Group 12 - GM 4 Cylinder Engine 1

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GM 2.2L 4 Cylinder Engine

Contents

Gate One

Group 12 has been assigned the task of analyzing a GM 4 cylinder engine. The purpose of Gate One is to establish an effective plan to disassemble, analyze, and reassemble the engine. Much of this gate is comprised of information generated by the intuition and research of a group of engineering students. The group has established a plan of action to perform the engine dissection. The plan includes proposals for working together in a group, working with another group, and handling the complexity of the task. The group has also complied sections of information that give insight into the engine itself, including development of the engine, usage, complexity, energy, and engine alternatives.

Work Proposal

The following information will provide a synopsis of how Group 12 plans to dissect and reassemble the GM 4 cylinder engine assigned to them. The proposal will include the methods of dissection and assembly, the tools needed to perform the tasks, group member attributes that pertain to the task, and a “game plan” for the gates of the project yet to come.


Dissection and Reassembly Plan/Overview

The general plan for the dissection of the GM 4 cylinder engine is to work from the outside in. In order to keep track of all the components and parts, the group has come up with an efficient system of labeling. Each part of the engine that is removed will be placed in a Ziploc bag and labeled. Each bag will be marked with the name of the part and where it came from, as well a number to be associated with the part. A detailed account of disassembly will be kept in a notebook to be used by both groups that are sharing the engine. The step by step process of how the engine is disassembled, including the numbers documented for each part, will be kept in the notebook. Keeping a detailed record of disassembly should enable a seamless reassembly.

Below is a diagram of how Group 12 plans to break up the project into subtasks over time:

Group 12 Gantt Chart


Because there are two groups working on one engine, the groups will take separate days to work in the dissection lab. Group 14, along with one member of Group 12, will work on Tuesdays; keeping a detailed record of the work they perform. Group 12, along with one member of Group 14, will work on Thursdays; picking up immediately were Group 14 left off and continuing the detailed record of disassembly.

No initial challenges were observed in the first inspection of the engine. The group plans to evaluate challenges accordingly as they arise. Due to the group’s general lack of experience with four cylinder engines, a timeframe for disassembly of the engine is difficult to generate.

The time frame for each stage to be completed is estimated to be approximately two weeks, which breaks down into about four lab sessions (each a few hours long)and two outside meetings. Four lab sessions should give Group 12 enough time to disassemble the engine, and another four sessions to reassemble the product.

Tools

The tools anticipated to be needed for dissection and assembly of the engine are as follows:

  • Torque wrench, SAE socket set and wrenches, open end wrenches and box wrenches
  • Basic handheld tools: wrenches, screwdrivers, rubber mallet, pliers
  • Shop press to remove the pistons from the rod
  • Piston ring remover (ring pliers)
  • Piston ring compressor (reassembly)
  • Feeler gauge to measure gaps (assembly)
  • Harmonic balancer puller (if it cannot be easily removed)

Group Member Attributes

The table below provides an overview of attributes that may help or hinder the group’s task of analyzing the GM 4 cylinder engine they are assigned. All group members anticipate using what helpful attributes they have to allow for the smoothest completion of the project, while developing themselves to eliminate what shortcomings they may have. The information provided in Table 1 is based on each group member honest assessment of themselves.

Table 1: Group Member Attributes
Group Member Positive Attributes/Capabilities Negative Attributes/Shortcomings
Marc Krug

- Can take almost anything apart
- Very good with tools
- Experience with basic engine repair
- MAE 177 AutoCAD experience

- Has never worked on a 4 cylinder engine
- Lacks in depth knowledge of an engine’s internal systems

Kari Puma

- Has some experience with tools, including socket sets and wrenches
- Doesn’t mind learning about engines and believes it will be beneficial
- 2 years of CAD experience and 1 year of inventor experience

- Knows absolutely nothing about engines

Erik Ibbett

- Has over three years of technical work experience
- Skilled in technical writing
- Has worked in a supervisory position

- Work experience is in electronics
- Limited experience with internal combustion engines
- No prior experience with wiki format

Joseph Scandurra

- Hands-on experience with engine rebuilding
- Has been working with power tools for roughly ten years
- Understands the use of different tools found in a workshop
- Understands the dynamics behind a 4-stroke engine

- Most of work experience is on two stroke engines
- No rebuilding experience with 4 cylinder engines

Christopher Galus

- MAE 177 AutoCAD experience
- Personal SolidWorks experience
- Previous hands on experience (bike maintenance, very simple car maintenance, etc)
- Loose understanding of internal combustion engine operations
- Ready to do as told

-No previous hands on experience with combustion engines
-Poor self-confidence
-No experience with technical presentation

Skills that need to be developed and improved among the group as a whole include solid modeling skills and technical communication and/or presentation. These skills are imperitive to the group's success and overall presentation of the project. Also, each member should improve their background knowledge of the engine before starting disassembly, so that there is an abundance of information available on hand during disassembly and reassembly.

Management Proposal

Group 12 has developed a management plan in order to ensure the assigned engine is disassembled, analyzed, and reassembled efficiently. The group has agreed on a regimented schedule to ensure everyone is on the same page, as well as to enable smooth collaboration with Group 14, who will also be using the 4 cylinder engine.



Meetings

Two meetings have been scheduled for every week until the project’s completion. The first of the two meetings will be held on Mondays at 5pm in the bottom floor of Capen Library. This meeting is reserved for the group’s main discussions. All assignments and deadlines will be discussed and established primarily during the Monday meetings. Internal deadlines will be set during this time to make certain each gate is finished with plenty of time to edit and format. During Monday meetings, group members will be asked to bring up problems they may be having, so as to ensure as many members as possible are present to offer democratic resolution to the issue. Group 14 will also meet on Monday to ensure both groups are going the same direction with the engine, as well as for sharing information that may have been discovered during the groups’ respective dissection times.

The second meeting of each week will be held on Thursdays. These Thursdays will begin in the bottom floor of Capen Library at 5:30pm. The group will take some time to discuss any troubles they may be having with their assignments and then the group will proceed to the dissection lab to work on the engine.

After every meeting an email will be sent out as a reminder of what was discussed, as well as to clarify any ambiguities. These emails will be sent by Group 12 Project Manager, Marc Krug.

Personnel

Table 2 gives a list of the group members in Group 12, the role/title of each group member, and a description of the duties that group member is expected to perform.

Table 2: Group Roles
Group Member Title Duties
Marc Krug Project Manager Enforce internal deadline; Preside over the settling of group conflicts; Go to professor with any group concerns; Send out post-meeting and other emails, Communicate with Group 14
Kari Puma Communications Liaison Access information needed for the project from the professor or Teaching Assistants; Wiki-page expert; Organize group and project information
Erik Ibbett Technical Writing Expert Proofread and format all assignment submissions; Ensure all final submissions are grammatically and technically correct as formatted
Joseph Scandurra Dissection Manager Keep record of lab dissection; Keep track of engine parts that have been removed from the main apparatus
Christopher Galus Technical Expert Handle any troubleshooting the group may have with technology; Maintain the group Google account

All group members will perform physical labor on the engine as well as divide the written work between one another equally.

Point of Contact

Group Twelve's point of contact will be Marc Krug, who can be reached via email at marckrug@buffalo.edu.

Collaboration and Conflict Resolution

Communicating well is essential to Group 12’s success in the dissection and reassembly of the engine assigned to them. Marc Krug from Group 12 and Mike Micieli from Group 14 will act as the groups’ arbiters. Inter-group communication will be done between them, permitting the groups to work together as effectively as possible. Group 14 has established their lab dissection day as Tuesdays; and, in order to guarantee that Group 12 has the information needed for analysis of the engine, one member from Group 12 will observe and take notes on the dissection that Group 14 performs. Group 14 will also send an observer to Group 12 lab dissections.

A Google account specific to the GM 4 cylinder engine groups has been created to allow for communication within the individual groups as well as between the groups themselves. Meeting summaries will be sent via the engine Gmail account. The group account will house availability schedules for all members of both groups working on the 4 cylinder engine, allowing quick reference in case an emergency meeting needs to be scheduled.

Conflicts between group members are asked to be brought up to the project manager. Conflicts that can be settled will be solved as a group during Monday meetings. More private conflicts will be resolved by private meeting with the project manager and/or the course professor. If the group members involved in such conflict do not oblige to the consenus agreed upon by the group manager, the professor will then be notified of the conflict, and group members may be asked to perform other tasks.


In the event that the lab is overly crowed or there is a lack of necessary tools for engine work, leading to the group being unable to work on the engine, the group will go to the library to work on assignments which would normally be done individually. This will ensure that the available time the group has together is not wasted. Additionally, group members will be looking into bringing and supplying their own tools to prevent future lab issues due to lacking proper devices.

Product Archeology

Disclaimer!
Portions of the product archeology were completed Group 14, who is also working on the GM 4 cylinder engine. These portions will be replaced in subsequent revisions of this wiki. The portions affected are annotated as such.

Development Profile

Group 14
The GM 4 Cylinder Engine that Groups 12 and 14 have been assigned was developed over a number of years. It was initially designed in 1982, but has been updated and reworked multiple times over the years into multiple versions until 1999.

In this time period, 1982 to 1999, a key global and economic concern was the rapid and powerful emergence of globalization. With such treaties as the North American Free Trade Agreement, products were able to be sold in multiple locations around the world, and manufactured in separate areas. This allowed corporations to maximize production efficiencies by producing products in places where labor costs are low and sell them elsewhere in places with higher demand. These conerns enabled the company to produce a cheaper engine for the consumer, or expand its own profit margin.

The GM Engine has a history which indicates that it was intended to be sold globally, specifically in industrialized areas with motor ways. The engine, over 3 million of which this general version were sold, was used in many vehicles such as Chevrolet’s early main compact, the Cavalier, to the S-10 pickup truck. Chevrolet, along with several subsidiaries of General Motors, is a worldwide producer and vendor; thus, this product is intended to be used in a variety of places around the wolrd where automobiles are driven.

This particular GM 4 Cylinder was designed to be used in multiple automobiles. Each of these individual automobiles often served different tasks, and performed them to varying degrees. However, the engine is designed to provide the power necessary to propel the vehicle and this basic task does not change from model to model. This in mind, it can be said that the intended impact on the consumer is the ability to, with regular maintenance, operate their automobile.

Usage Profile

Group 14
This model of GM engines has been used in multiple GM vehicles through multiple subsidiaries, including GMC, Chevrolet, etc. Its use in a variety of vehicles does not affect the primary intended use of the 4 Cylinder block. As an engine, its basic intended function is to be the main source of power to the vehicle. As the power production to a vehicle, it is intended to allow the users transportation.

This engine is designed for both home and professional use. The Chevy Cavalier is a sedan marketed as a means of transportation to and from work and daily activities. The S-10 can be used both as an individual’s daily mode of transportation as well as an "on the job" truck. Professionally, businesses often use pickup trucks for tasks that go beyond the capabilities of small compacts and sedans. The most common use of a pickup truck in professional service is as a way to transport items to and from job locations and as a way to move finished products from a warehouse to home consumers.

The engine is used in situations where multiple jobs are being performed. This product can be placed and called upon anywhere a smaller sized engine is needed to provide power. So while there are possible unconventional uses for it,such as powering a generator or a compressor, the most common of the engine’s intended uses is to be the main power provider to small scale GM vehicles. Within this job, the engine’s power is doing multiple tasks, such as powering the vehicle’s electronics, supplying the force need to move the vehicle, as well as running the cabin environment controls.

Energy Profile

Figure A: Energy Flow Chart

The General Motors 2.2 litre, four cylinder engine’s primary function is to transform chemical energy into rotational energy. Chemical energy in the form of petroleum is supplied to the engine via the fuel pump, which distributes fuel to the individual cylinders through the fuel rail and injectors. Electrical energy, partially converted to heat energy by the spark plugs, is used to initiate combustion in each cylinder, in intervals set by the distributor. Through this combustion, the petroleum’s chemical energy is converted into heat and pressure, which forces the pistons into linear motion. This linear kinetic energy is transferred to the crankshaft via the piston rods, and is there transformed into rotational energy. While the greater portion of the engine’s power output is used to provide motion to the vehicle in which it is situated, some of the energy is also used to run ancillary systems such as climate control, and power-assisted handling. More importantly, though, some of the rotational energy at the crankshaft is used to keep the engine itself running. To this end, some output energy is used to drive the fuel pump and alternator, which maintain fuel flow and provide necessary electrical energy to the engine, respectively.

Complexity Profile

Group 14
In creating a complexity file for this product we have made the following assumptions: - Complexity will be defined as a group of diverse components operating together in some fashion to perform a higher function. Removal of any of the components prevents the function from being accomplished and an increase in variety is a more complicated group. - Gate 1 detail will include general types and applications of parts and assemblies, but not a complete bill of material. - The team has taken the definition of a part to be, “the smallest denominator of a device that can accomplish the function it was intended to perform”. - Some generalizations will be made to describe the parts until the engine dissection occurs. - The object of the project is a 2.2L GM 4 Cylinder Automotive Engine

How many components are used?
The engine is made up of roughly three hundred “components” and is summarized in the classifications below while an attempt is also made to give a rough idea of what components make up the engine:
Bolts & Nuts: There are approximately twenty to thirty types of bolts or nuts in this application and they are by far the largest single group of components by number count, probably 30% of the engine. They are used to join two components together and in several instances, use common fastener designs. They are used to join large components, like the engine block to the header, and to smaller items, such as the oil filler neck.
Gaskets & Seals: These would include gaskets between main components to seal from air, oil, and other fluid contamination or leaks. Also, o-rings, compression seals, and mechanical seals for higher pressure environments. With gaskets being in these situations, it is reasonable to say that there are a small number of them and probably make up 5% of the total components.
Electrical components: Including spark plug wires, spark plugs, the main electrical harness, sensor wires, distributor and coil components, including attachment brackets, sensors for coolant temp., oxygen, and oil pressure. With few electrical components for the engine itself, they most likely make up 15% of the total amount.
Main Housings: The smallest category by amount, these are large singular pieces represent around 5% of the motor and consist of the engine block, cylinder head, manifold, valve cover, intake manifold, and oil pan.
Internal engine components: In this type of engine, many smaller components are used in properly timing and running the engine. With about 25% of the engine comprising of parts such as the crank shaft, cam shaft, oil pump, timing chain and gears, pistons and connecting rods, various bearings and journals, sleeves, valves, lifters, springs, push rods, and rocker arms.
Accessory drives, exhaust & fuel delivery: Something around 20% of the remaining parts are auxiliary pieces required for the engine to receive all the proper conditions for operation. This includes but is not limited to, the Water pump, thermostat, pulleys (several different), belt tensioner, exhaust manifold, fuel injectors, throttle body, fuel rail, oil filter, and oil filler tube.
How complex are the individual components?
An interesting situation with an engine, and many other mechanical devices, is if it were to be broken down to all its singular parts, no one part would strike a person as being a very complex piece. A few larger components might be consider complex, such as the timing chain which consists of a variation of stiff pieces to achieve a belt like motion and give proper timing to the engine.
How complex are component interactions?
As parts are combined to created larger components, complexity in the engine tends to increase dramatically. A few pieces alone, such as the valves, lifters, springs, rocker arms, create a very important and complicated action with multiple parts that are very different in nature. The interaction between the cylinders, pistons, connecting rods, and crankshaft are very complex. Together these parts manage to, with the proper combustion, turn reciprocal motion into rotational motion. Over all, the entire engine and all of its many varied components, are operating to turn chemical energy stored in a fuel into a constant and controllable rotational motion.

Materials Profile

Group 14
Engines are comprised of a number of materials. The materials that make up GM’s 4 cylinder engine are chosen for a number of reasons. Durability, strength, weight, and cost effectiveness are all taken in consideration when a material is chosen for a specific component.

Visible Material

The most abundant materials in the engine are by far metals.

  • The largest single piece, the engine block, is cast and machined iron because it is strong, durable, and much cheaper than its aluminum alternative.
  • The exhaust manifold is also cast iron.
  • Stamped steel is also used for things like the oil pan and oil filter most likely because it is relatively cheap and easy to manufacture.
  • Steel is also used for parts like gears, serpentine belt pulleys, and bolts because of steels strength and cost effectiveness.
  • Aluminum is used on the engine as well.
  • Parts like the water pump are made out of aluminum because of its lightweight as well as it is relatively cheap.
  • Plastic and rubber are also used.
  • Parts such as hoses, dipstick cap, spark plug wires and hose and wire brackets

Non-Visible Materials

Metals are used as much on the inside as they are on the engine.

  • The cylinder head, valves, and pistons are most likely comprised of cast and machined iron or aluminum. While iron is more durable and inexpensive, aluminum is lighter weight but more expensive.
  • Steel or iron is probably used for other parts such as the camshaft, crankshaft, rocker arms, springs, and internal bolts. This is because of the strength, durability, and cost effectiveness of steel and iron.
  • Stamped steel or rubber is almost certainly used for gaskets to create an air or liquid tight seal on parts like the valve cover, oil pan, or dipstick cap.

User Interaction Profile

User Interfaces

The engine assigned to Group 12/14 was intended to be mounted and used inside of a commercially available vehicle. This allows assumption to be made that the user will interact with the engine predominately as the operator of the vehicle(with the possible inclusion of maintenance and repair which will be explained later). The user sits inside the vehicle and controls the power output of the engine with a throttle cable connected to a pedal that is pressed with the user’s foot. Conventionally, combustion engines in public vehicles are initially started with a starter motor that the user activates with the vehicle’s key. This engine, however, does not currently have a starter motor mounted to it. In conjunction with directly controlling the engine’s performance, the user has access to information about the engine’s condition, which is displayed to the user while inside the vehicle. This is evident through the multiple electronic connections on the engine, which are linked to sensors for providing vital data such as engine temperature, oil pressure, and engine speed (rpm's).

Beyond the operation of the engine, the user and/or others interact with the engine during periods of maintenance and repair. For these situations, the engine has additional parts added and certain aspects specially designed. Firstly, there is a metal band extended down into the engine’s internals, which can be removed to check oil levels. This part’s existence does not directly impact the engine’s operation, but is required to maintain oil amounts needed for performance. For part repair/replacement the engine is built and designed in a manner to allow a person access. There are protrusions on the main engine block which aid in handling and moving the engine. Bolts and small parts (such as spark plugs) are positioned in a manner to allow space for the necessary tool and removal of the part. It should be noted that while these additional design aspects help repair and maintenance, the average operator would still be troubled in attempting to do it without the proper understanding and tools.

The idea of something being intuitive implies that without prior knowledge and understanding of the object, a person can very quickly begin using it properly. In this sense, an internal combustion engine can be intuitive. It can be difficult for an average user to understand or know much about the engine’s processes for performing, but with short trial time or sometimes simply observing another operator, the use of the engine by a new user can be learned readily. Operation aside, maintenance and repair of the engine requires a much deeper understanding of how the system works, and does not lend itself readily to an average operator.

Where intuitiveness deals with how quickly a user can operate the engine, ease of use deals more with what the user is doing while operating it. During operation, a user can expend very little energy to get the desired performance from the engine. An average user does not need to be physically conditioned in any way to effectively operate the engine. Also, ease of use is shown in that once an individual learns the basics of operation, using the engine can almost become a second nature.

Maintenance

The performance of the engine is a process that can degrade over time and does require proper maintenance to continue operation. The system is not frictionless and there is motion so there is energy expended into the engine that causes wear on parts. This wear should be regularly checked through maintenance and repair. As implied and stated previously, neither the repair nor maintenance can be an easy or intuitive process. This is evident in the entire field of auto-mechanics who cater to doing maintenance and repair on engines for the average user who is unsure of what to do or lacks the tools required.

Product Alternatives

Group 14

Existing Alternatives
A similar alternative is the Mazda F2 2.2L SOHC engine.
Advantages
Unlike the OHV (Overhead valve) engine, a SOHC (single overhead camshaft) engine controls the valves in the engine. At higher rpm’s the valve timing is almost perfect thanks to the camshaft. Better timing improves the quality of the air mixture in the combustion chambers as well as the overall efficiency of the engine. The alternative also has a lower inertia on its valve since it does not require extra components such as lifters, pushrods, and rocker arms to control valve timing. Also, SOHC engines have the capability to install three to four valves per cylinder, while OHV engines can only have two valves per cylinder due to the difficulty in implementing new technologies. This particular engine has twelve valves compared to the eight on the GM engine.
Disadvantages
SOHC engines require certain timing belts or chains with similar components to keep the camshaft running. This alternative is much more complex than the OHV engine due to the different components and the positioning of the camshaft. It is also much more expensive because of the complex parts and the four extra valves.
Performance Comparison
The GM 2.2L OHV engine has a horsepower of 120 hp at 5000 rpm, while the Mazda F2 SOHC engine has a horsepower of 110 hp at 4700 rpm. Also, the OHV engine has a torque of 140 ft-lb at 3600 rpm and the SOCH engine has a torque of 130 ft-lb at 3000 rpm. Even though the SOHC is more complex and has twelve valves compared to the 8 valves in the OHV, the OHV engine out performs the SOHC in terms of horsepower and torque.
Cost Comparison
Since the GM OHV comes from a 94’ S-10 and the Mazda SOHC comes from 91’ Ford Probe and 92’ Mazda MX6, these engines can only be bought used (refurbished). The Mazda engine costs $2180.00 while the GM engine costs $1400.00. The big difference in the prices is the complexity of the Mazda engine. The OHV is a much more simple and durable engine than the SOHC so it costs less.

Gate Two

Using the plans that were generated and the information gathered in Gate 1, Group 12 disassembled the GM 4 cylinder engine. For Gate 2 of the project, Group 12 disassembled the engine, documented the process step by step, and compiled information on the engine’s interconnections. Along with disassembling the engine, Group 12 also assessed the original work and management proposals from Gate 1, and considered corrective actions for any troubles faced during Gate 2 or any troubles foreseen in the future gates.

Preliminary Project Review

As Group 12’s project progresses, the work and management proposals initially established in Gate 1 of the project may need to be amended in order to be successful. Causes for corrective action would be any discrepancy in the initial proposals that caused the group a waste in time, or an unforeseen problem, and the group had to go out of the bounds of the proposal to correct those discrepancies. The following are the troubles or lack thereof which have appeared to date.

Work Assessment

The work proposal developed by Group 12 has worked quite well, with only minor discrepancies in the plan. Most of the problems that developed while working on the engine were due to the group’s general lack of detailed knowledge about the engine, but even that lack of knowledge provided only minor hindrances.

The lack of knowledge caused difficulties mainly in the documentation of the engine. As a component or part was removed from the engine, it was placed in a bag with its fasteners, and named. Naming some components or parts with no previous knowledge of their function proved to be difficult. In hindsight, names such as “gray sensor” or “rounded pulley” do not provide an accurate representation of the component or part’s location on the engine, function, etc. The group could have taken the following preventative measure to insure greater ease of disassembly documentation: While Groups 12 and 14 were taking off each component or part, there should have been some sort of reference to where on the engine the part was located.

The group’s lack of knowledge also lead to minor difficulties when deciding upon a way in which a component or part should be removed, or in what order certain components or parts should be removed. Difficulties arose when group members did not know what a specific component or part was. This could be not knowing the part's existence or function, or knowing of a part but not knowing where it was or what it looked like. The harmonic balancer, the crankshaft, and the timing chain were the components that the group ran into difficulty with. The group knew of the harmonic balancer and knew how to remove it, but the group did not know where it was or what it looked like. When Groups 12 and 14 came across the harmonic balancer during disassembly, time was wasted just trying to figure out what it was before we could remove it. When the Groups 12 and 14 got to the crankshaft, they assumed it simply slid out. The groups were not aware that the gear that runs to the distributor needs to be removed before the crankshaft could be removed. The timing chain provided difficulty because Groups 12 and 14 were under the impression that there would be a master link to remove the chain, and time was again wasted until it was realized that the timing chain came off when the gears were pulled.

In general, the difficulties faced during Gate 2 of the project from a work standpoint could have been prevented if a plan for research was included in the work proposal. One or more members of each group should have been assigned the task of researching the components of the engine, their location, and what they look like. It would have been beneficial for the group to look up videos of previous engine dissections so that a disassembly plan could be drawn up in more detail.

Management Assessment

The management proposal developed by Group 12 in Gate 1 of this project worked seamlessly. Meetings went as planned, personnel performed their assigned tasks as established, and there was no need for conflict resolution, to date.

The success of the management proposal is due partly to how thoroughly it was planned out when it was established, and partly to how studiously the members of Group 12 are performing at this point in the project.

No official timeline for the project was established in Gate 1 of the project, yet work is getting done on schedule, and in the case of disassembling the engine, work is being completed well ahead of schedule thanks to the efficiency at which Group 12 is running, as well as the efficiency at which Groups 12 and 14 are collaborating on the shared parts of the project.

There appears to be no need for corrective action as far as the management side of the project is concerned. This may change as the project progresses, because the intensity of other courses that individual group members are taking may increase as the semester progress. Other classes’ work loads are something that Group 12 has to keep in constant thought due to the diversity of those courses due very much to the fact that Group 12 is composed of sophomores and juniors.

Product Dissection

Ease of Disassembly

With the difficulty of a task varying from one individual to another, creating a scale for gauging it can be troublesome. The rating system for this gate will split up and consider two sides of a particular task, the tangible/physical requirements and the mental/knowledge requirements. If assembling or removing a component takes large amounts of force, it will be physically difficult. If a task requires special knowledge, it will be mentally difficult. This difficulty also will consider time for each task. Some tasks may consume large amounts of time and indicate a difficult step, though it should be said that some steps are simply many easy tasks and are not difficult despite the time taken.

In this engine disassembly, the scale of difficulty will begin with the removal of a simple bolt. This level of difficulty will be rated as a 1. A 1 level difficult will be a process that takes very little time to finish, requires little physical and mental effort, and can be accomplished with basic tools (socket wrench, screw driver, even hands).

A level of 2 will imply a medium degree of difficulty. This is a task that consumes more time than an easy process, required more effort/force than an easy task, or needed more mental attention than an easy task. While a 2 shows the removal of something that acted as an obstacle, that step did not cause serious interruption of the disassembly.

A level 3 is a rating of hard and is the highest level of difficulty. Something of this level requires a special tool, a very large amount of force, a great deal of time, and/or some thought.



Figure AA: Engine Assembly

Step by Step Dissection

Table 3, below, is a step by step disassembly of the GM 4 cylinder engine assigned to Groups 12 and 14. The disassembly was performed and documented as a collaborative effort with Group 14. During the dissection process members from both groups were always present to ensure both groups gained as much valuable experience with the engine as possible.

Table 3 includes the components/parts of the engine, how those components/parts were taken off the engine, the tools needed to take off the each component/part, and a picture of the component/part. It is important to note that the engine was disassembled while on an engine rotisserie, and unless stated within the step, the engine was right side up. It is also important to acknowledge that all threads on the engine required counterclockwise motion to loosen them and clockwise motion to tighten them. Figure AA below shows a basic diagram of a pushrod engine, and the parts are numbered and listed to the right of the diagram. The some of the parts listed below in the table correspond to a component and its position shown in figure AA.

Table 3: Step by Step Dissection
Step # Part Procedure Tools Used Difficulty Image
1 Spark Plug and Spark Plug Wires Unscrew three 10 mm bolts and disconnect the three spark plug wires from the distributor and remove the three corresponding spark plugs. hands, 10 mm socket, 1/4 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Sparkplugsandwires.jpg
2 Coolant Tube Remove one 13 mm hex nut and one 15 mm hex nut and disconnect the coolant tube. 13 mm & 15 mm sockets,3/8 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (nut), allowing it to be removed by any person with a proper socket set. Coolant tube.jpg
3 Fuel Rail Assembly Unscrew two 10 mm mounting bolts and remove the fuel rail. 10 mm socket, 1/4 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Fulerailassemblyg14.jpg
4 Intake Assembly Remove three 13 mm standoff bolts, two 13 mm mounting bolts, two 13 mm hex nuts, and disconnect the sensor wire; remove the intake assembly. 13 mm socket, 3/8 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt, nut), allowing it to be removed by any person with a proper socket set. Intake assemblyg14.jpg
5 Oil Filter Unscrew the oil filter. hands 1, this part was designed to be removed, evident by the method of connection (thread), allowing it to be removed by any person with a proper wrench set. Oil filterg14.jpg
6 Vacuum Sensor Loosen the 16 mm black vacuum sensor. 16 mm socket, 1/2 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (thread), allowing it to be removed by any person with a proper wrench set. Vacuum sensor14.jpg
7 Dipstick Tube Remove one 16 mm mounting bolt on the dipstick and disconnect it from the engine block. 16 mm socket, 1/2 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Dipstick tubeg14.jpg
8 Exhaust header/manifold (including O2 sensor) Unscrew four 13 mm hex nuts on the exhaust header/manifold and remove it along with the O2 sensor. 13 mm socket, 3/8 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (nut), allowing it to be removed by any person with a proper socket set. Exhaust manifoldg14.jpg
9 Valve Cover Remove the six 10 mm bolts along the edge of the valve cover. 10 mm socket, 1/4 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. ValveCover.png
10 Rocker Arms and Pushrods Loosen the eight 10 mm bolts within the rocker arms and pull out the eight push-rods located inside of the valve assembly. 10 mm socket, 1/4 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Rockerarmsg14.jpg
11 Distributor Unscrew the three 13 mm mounting bolts on the distributor and remove distributor. 13 mm socket, 3/8 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Distributorg14.jpg
12 Water Pump Pulley Remove two 13 mm mounting bolts on the belt tensioner pulley. 13 mm socket, 3/8 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Waterpumppullyg14.jpg
13 Mounting Bracket Unscrew the four 13 mm bolts on the mounting bracket and pull off. 13 mm socket, 3/8 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Mounting bracketg14.jpg
14 Distributor Mounting Bracket and spacer Remove the five 8 mm bolts behind the Distributor and pull off the mounting bracket and spacer. 8 mm socket, 1/4 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Distributor mounting bracketg14.jpg
15 Valve Housing Remove the five 15 mm external bolts and five 15 mm internal bolts connected to the valve housing and lift the assembly off the engine block. 15 mm socket, 1/2 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Vlave houseingg14.jpg
16 Black mount for coolant thermostat Unscrew the two 8 mm bolts on the black housing connected to the coolant thermostat. 8 mm socket, 1/4 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Blackmountforcollantthermostatg14.jpg
17 Spring gasket for coolant thermostat Pull out the spring gasket housed inside the coolant thermostat. hands 1, this part was designed to be removed, evident by the method of connection (loose), allowing it to be removed by any person with a proper socket set. Springgasketforcoolantg14.jpg
18 Silver coolant thermostat housing Unscrew the two 13 mm bolts on the silver coolant thermostat and disconnect it. 13 mm socket, 3/8 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Silvercoolantthermostathousingg14.jpg
19 Belt tensioner pulley Remove the one 16 mm bolt on the water pump pulley/assembly and pull off the pulley. 16 mm socket, 1/2 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Belttensionerpullyg14.jpg
20 Belt Wheel Unscrew one 18 mm bolt with an accompanying washer and three 13 mm bolts that connect the belt wheel to the harmonic balancer. 18 mm & 13 mm sockets, 3/8 & 1/2 drive ratchets 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Beltwheelg14.jpg
21 Oil Pan Remove twelve 10 mm bolts and twelve 10 mm washers from the outer edge on the bottom of the oil pan and lift off the pan. It is suggested the engine be upside down for this step. 10 mm socket, 1/4 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Oilpang14.jpg
22 Oil Pump Unscrew two 15 mm bolts connecting the oil pump to the bottom of the oil pan and end the end of the crankshaft. It is suggested the engine be upside down for this step. 15 mm socket, 1/2 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Oilpumg14.jpg
23 Crankshaft clamps Remove eight 15 mm bolts on the U clamps holding the crankshaft in place. (The order goes Blue, Green, Orange, Pink from the back of the crankshaft to the front.). Use a rubber mallet to tap the clamps until they are loose enough to remove. It is suggested the engine be upside down for this step. 15 mm socket, 1/2 in drive ratchet, rubber mallet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Crankshaftclampsg14.jpg
24 Oil Pressure Sensor Unbolt the one 8 mm bolt holding the oil pressure sensor down to the oil pan. 8 mm socket, 1/4 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Oiltemperaturesensorg14.jpg
25 RPM Sensor Unscrew the one 8 mm bolt connecting the RPM sensor to the engine block. 8 mm socket, 1/4 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. RPMsensorg14.jpg
26 Temperature Sensor Unscrew the 22 mm temperature sensor from the engine block. 22 mm open end wrench 1, this part was designed to be removed, evident by the method of connection (thread), allowing it to be removed by any person with a proper socket set. Temperaturesensorg14.jpg
27 Back Crankshaft Clamp Remove one 15 mm bolt from the large U clamp on the back of the crankshaft. It is suggested the engine be upside down for this step. 15 mm socket, 1/2 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Backcrankshaft clamp.jpg
28 Piston Clamps Using vice grips to grasp the nuts unscrew eight 13 mm nuts (2 from each clamp) from the four piston clamps and pull them off. It is suggested the engine be upside down for this step. vice grips 1, this part was designed to be removed, evident by the method of connection (nut), allowing it to be removed by any person with a proper wrench set. Pistonclamps.jpg
29 Pistons Tap out the pistons from each of their cylinders. rubber mallet 1, this part was designed to be removed, evident by the method of connection (friction), allowing it to be removed by any person with a rubber mallet socket. Pistonclampsg14.jpg
30 Push-rod Guides Remove two 10 mm bolts from each of the four plastic push rod guides (10 from each guide) and pull them out of the engine. 10 mm socket, 1/4 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt, friction), allowing it to be removed by any person with a proper socket set. No Image
31 Push-rod Seats Pull out the eight push rod seats using hands or pliers when necessary. hands, needle nose pliers 1, this part was designed to be removed, evident by the method of connection (loose), allowing it to be removed by any person able to pull it out. Pushrodseatsg14.jpg
32 Camshaft Pulley Unscrew the one 15 mm bolt holding the camshaft pulley up in front of the camshaft. 15 mm socket, 1/2 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Camshaftpullyg14.jpg
33 Harmonic Balancer Using a gear puller, pull off the harmonic balancer (lots of force). Be sure that the gear puller is pulling straight. gear puller 3, this part was not designed to be removed be an average user. It requires a high amount of force and a specialized tool (harmonic balancer/gear/steering wheel puller) which also warrants is a high difficulty rating. However, this would be something a mechanic could readily take care of and remove the part. Harmonicbalancerg14.jpg
34 Timing Gear Cover Remove the six 8 mm bolts holding the timing gear cover in place on the side of the engine block. 8 mm socket, 1/4 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Timinggearcoverg14.jpg
35 Chain Tensioner Unscrew one 11 mm bolt, one 11 mm washer, and one T-40 Torx screw keeping the chain tensioner component in place. 11 mm socket, 1/4 drive ratchet, T-40 Torx screwdriver 1, due to the location of this part (behind the harmonic balancer), it was not designed to be removed, evident by the method of connection (bolt, Torx screw). These issues would make it nearly impossible for an average user to remove this part. This could still be removed by a mechanic. Chaintensionerg14.jpg
36 Timing Chain Asembly Remove one 15/16” bolt from the timing chain assembly. After the bolt is removed, place the wrench between the engine block and the gear and use it to pry off the gear. 15/16 in open end wrench 2, this part was not designed to be removed by an average user, evident by the position (behind the harmonic balancer). Knowledge was required in properly removing the gear and chain, along with a high difficulty level, a mechanic would be more able to remove this part. Timingchainasemblyg14.JPG
37 Crankshaft Lift out the crankshaft, which is now completely loose. It is suggested the engine be upside down for this step. hands 1, this part was not designed to be removed, evident by the position (behind the harmonic balancer) which provides the only obstacle for an average user. A mechanic, who removed the harmonic balancer, could easily lift free the crankshaft. Crankshaftg14.jpg
38 Distributor timing gear Unscrew one 10 mm bolt holding the distributor timing gear in place. 10 mm socket, 1/4 in drive ratchet 1, this part was designed to be removed, evident by the method of connection (bolt), allowing it to be removed by any person with a proper socket set. Distributortiminggearg14.jpg
39 Camshaft Pull out the camshaft rotating when necessary to make sure the camshaft clears all holes. hands 2, this part was not designed to be removed, evident by position (behind the harmonic balancer). The part requires some forethought to know to remove the distributor timing gear and to position it correctly while pulling it out. This gives it a higher difficulty rating, and offers an additional obstacle to the average user. Again, for maintenance and repair, a mechanic could still easily remove the part. Camshaftg14.jpg
40 Oil Temperature Sensor Unscrew oil temperature sensor on the side of the engine block. hands 1, this part was designed to be removed, evident by the method of connection (thread), allowing it to be removed by any person with a proper socket set. Oilpressuresensorg14.jpg

Connection of Subsystems

The motor implements a variety of subsystems in order to perform the overall function of converting chemical energy into rotation. Each of these physical groups of components performs a variety of functions working in tandem, and rely on one another in various ways for operation. In other words, none of the subsystems are able to effectively operate independently. The engine can be broken into subsystems as follows:

  • Intake and Fuel Delivery
  • Valve Train
  • Block
  • Lubrication
  • Electrical
  • Ancillary Drive

A multitude of interconnections is required to allow the engine to operate. Each subsystem is physically connected in a way which enables effective material, signal, and energy transfer as needed to function properly. Also taken into account in the physical connections are space economy, maintenance, and efficiency.


Figure A1: Engine Block


The largest physical subsystem in the GM motor is the block, which forms the center of the engine’s mass and serves as the main physical connection point for the other subsystems,as shown in figure A1. The valve train is bolted directly to the top of the block. Its location here is necessary for effective performance, as the valves provide an entry and exit path for material flow into and out of the block.

The location of the intake and fuel delivery system is also based on enabling effective material flow and efficient performance. It is bolted to the valve train, to which it provides a mixture of air and fuel. The lubrication system is also involved in material transfer, sending oil to and from the moving parts contained in the block and valve train. The largest component of this subsystem, the oil pan, is bolted beneath the block, and is located here so as to keep the oil reservoir at the lowest point in the engine. This allows gravity to return the lubricant to the pan, and also enables user maintenance, as the engine therefore need not be removed to perform an oil change. User maintenance can be considered both a societal and economic concern.

The ancillary drive subsystem is physically and mechanically connected to the front of the engine block, at the crankshaft. This subsystem provides mechanical power to ancillary systems in the automobile, and mechanical timing signals to the valve train and distributor, via a camshaft located in the block. Its direct attachment to the crankshaft avoids unnecessary mechanical linkages and is therefore the most efficient location for the subsystem.

The primary component of the electrical subsystem, the distributor, is mechanically connected to the camshaft in the block, and sends electrical power to the spark plugs as required to combust the air/fuel mixture in intervals determined by the angular velocity of the mechanical input. The distributor is physically located at the rear of the valve train, to which it is bolted. Also included in the electrical subsystem are various sensors, which provide performance data to the vehicle’s electronic control unit and gauge panel. These sensors are located where they can effectively acquire data—be it temperature, pressure, flow rate, gas composition, or rotational speed.

Most of the subsystems and their components are physically connected using metric bolts. This decision reflects a global concern; namely, by using the metric sizing, the engine can be maintenanced in any country, permitting global sales.

The choice of materials used for subsystem connections reflects economic and environmental thinking on the part of the designers. The main material used for these connections is aluminum; this material was chosen for its strength to cost ratio and availability. When comparing aluminum to a material like titanium, it is obvious to use aluminum for connection from an economic view because of the material costs. Aluminum is also easily recycled, showing how environmental factors may have played into the design of this engine. Iron is also used prominently used because it is a strong, easily casted material that can withstand high pressure and high temperatures. Grey cast iron is used in the engine block, malleable iron is used for parts of the crankshaft, and a ductile iron is used for parts of the camshaft.

Gate Three

For this Gate, Group 12 was tasked with analyzing the engine on the component and subsystem level. The Gate will first discuss project management on the basis of problems faced and problems solved on a management and work level. Then, the Product Evaluation will list the components of engine and give insight into each component's function and manufacturing (the information for the component summary was gathered in collaboration with Group 14). The group has also modeled a push rod and rocker arm assembly to analyze the interactions between components. With all the knowledge gained from investigating each component, the group has come up with, and will present within the Gate, an engineering analysis of a subsystem of the engine as well as three design revisions that could be made on the engine.

Coordination Review

Work Assessment
There were no conflicts or problems within Gate 3 as far as actual work on the engine. All work in the lab was done on time as well as effectively. This success was half due to a well established work proposal, and Group members' willingness to do the work and do it well. The next Gate requires the engine to be reassembled. Based on how effortless the disassembly of the engine was (on a labor basis) there are no foreseeable problems with the labor involved in the next Gate.

Management Assessment
There was one discrepancy from a management standpoint that had to be fixed during Gate 3. Sections of Gate 2 that were completed were not posted on the wiki and the group was penalized for not having them. This discrepancy is due very much too human error as well as an inefficient proofing system. Initially it was only one group member’s job to proof the final submission of the Gate, but this method lacks and double checking making leaving out an entire section much more likely. Now, that method has been ameliorated. The Technical Writing Expert’s and Group Manger’s job is to email the rest of the group when the Gate is up on the wiki and can be read. The rest of the group is then obligated to know what the Gate involves and requires, and check over the posted Gate, being sure to immediately send out notification if there is something wrong with the Gate.

The future Gate at a glance appears to be very similar to the first Gate of the project; and due to the overall success of the management during the first Gate, there are no foreseeable problems for the next gate as far as management is concerned.

Component Summary

The following is a list of all the components of the GM 4 cylinder engine that this project focuses on. The components are organized in to groups based on their functions. The following information will be provided for each component: Part Number, Approximate Weight, Materials, Manufacturing Method, Basic Function, Amount of that Part, Approximate Dimensions, and Associated Dissection Step (in reference to Gate 2). Most of the engine components are not visible when the engine is assembled an functioning within vehicle and therefore most components have little to no aesthetic purpose beside that which provides functionality. The few notable aesthetic properties are as follows: the labeling on the dipstick tube’s cover, and the components that are painted black. The black paint can make the engine look more appealing, but it also serves the purpose of protection those components from rusting. The label on the dipstick tube’s cap gives indication on what the component is and its purpose. The labeling helps to make maintenance more user friendly.

Note that the nuts, bolts, screws, and washers, are mention in the fasteners section, but due to the sheer amount of them dimensions, weights, part numbers, and dissection steps will not be mentioned.

**Please refer to the "associated dissection step" for photos of each component, where none is present**



=== Sensors ===

Vacuum Sensor

Part #: 1997278

Weight: 0.5 lb

Materials: plastic, steel

Photograph: http://gicl.cs.drexel.edu/wiki-data/images/4/46/Vacuum_sensor14.jpg

The vacuum sensor is manufactured with:

  • A stamped plate, evident in its thin width and bent edges
  • Injected molded body, with visible seam lines and plastic material

Function: Measures manifold pressure and mass flow rates to determine the best ration of inputs for maximum combustion.

Amount: 1

Dimensions:

  • Overall Height: 10 cm
  • Width at Largest Point: 7 cm

Associated Dissection Step: 6


Oil Pressure Sensor

Part #: 6617008

Weight: 0.25 lb

Materials: brass, plastic, rubber

Photograph: http://gicl.cs.drexel.edu/wiki-data/images/7/7a/Oiltemperaturesensorg14.jpg

The oil pressure sensor is manufactured by:

  • Lathed brass end, visible in the groove marks around the part and the part's axial symmetry
  • Injected molded O-ring, evident by the seam line and pliable material
  • Injected molded connector, evident in the seam lines and the plastic material
  • Stamped center piece, supported by its small thickness

Function: Measures the pressure of the oil and relays the information to determine the amount of oil needed for the best performance of the engine.

Amount: 1

Dimensions:

  • Diameter: 1 cm
  • Height: 6 cm

Associated Dissection Step: 24


RPM Sensor

Part #: none

Weight: 0.25 lb

Materials: steel, plastic, rubber

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/2/2d/RPMsensorg14.jpg

The RPM sensor is manufactured by:

  • Injected molded connector, evident by the seam lines and plastic material
  • Injected molded O-ring, visible in the seam lines and pliable material
  • Stamped aluminum end, evident by its very thin thickness

Function: Reads the window (notch) on the fly wheel to determine when the one piston is making a stroke and thereby determine the rotations of the engine.

Amount: 1 Dimensions:

  • Diameter: 1.75 cm
  • Height: 8 cm

Associated Dissection Step: 25


Temperature Sensor

Part #: 10456209

Weight: 0.25 lb (all plugs and wires)

Materials: brass, plastic, steel

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/d/d2/Temperaturesensorg14.jpg

The temperature sensor is manufacture by:

  • Injected molded connector, evident by the plastic material and seam lines
  • Lathed fitting, which is visible in the axial symmetry of the component and the circular grooves
  • Machining, the part has an external thread on one end which would require machining to make

Function: Measures engine temperature and relays information that helps to determine the best ratios for combustion and engine performance.

Amount: 1

Dimensions:

  • Larger Diameter: 3.5 cm
  • Smaller Diameter: 1 cm

Associated Dissection Step: 26


Oil Temperature Sensor

Part #: 24575739

Weight: 0.25 lb (all plugs and wires)

Materials: plastic, steel

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/a/ad/Oilpressuresensorg14.jpg

The oil temperature sensor is manufactured by:

  • Injected molding, evident in the seam lines and the plastic material use
  • Die casting, visible in the part's rough surface finish
  • Machining, due to the external threading on the end of the cast section

Function: Measures oil temperature and relays information that helps to determine the best ratios for combustion and engine performance.

Amount: 1

Dimensions:

  • Height: 5.5 cm
  • Diameter: 2 cm

Associated Dissection Step: 40


O2 Sensor

Part #: none

Weight: 0.25 lb

Materials: aluminum, plastic, copper, rubber

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/6/64/Exhaust_manifoldg14.jpg

The O2 sensor is manufactured by:

  • A drawn wire, thin in diameter
  • Injected molded connector, with visible seam lines
  • Cast protrusion, evident by the rough surface finish
  • Machining done to the protrusion, shown by the addition of threads to the piece

Function: Reads the oxygen content of the exhaust and relays information to determine if the proper amount of oxygen is present during combustion.

Amount: 1

Dimensions:

  • Length of Sensor: 8.5 cm
  • Length of Sensor and Wire: 34 cm
  • Diameter at Widest Point: 2 cm

Associated Dissection Step: 8



=== Pulleys and Gears ===

Water Pump Pulley

Part #: 24576031 JA

Weight: 2.5 lb

Materials: steel, plastic, aluminum

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/a/aa/Waterpumppullyg14.jpg

The water pump pulley is manufactured by:

  • A stamped metal wheel, evident by its relatively thin width
  • Extruded center, visible by the constant cross-section Function: Receives torque for and transmits it to the water pump in order to power the water pump.

Amount: 1

Dimensions:

  • Diameter: 11.5 cm
  • Height: 11.5 cm

Associated Dissection Step: 12


Belt Wheel

Part #: 10112371

Weight: 1.5 lb

Materials: Steel

Photograph:http://gicl.cs.drexel.edu/wiki/File:Beltwheelg14.jpg

The belt wheel is manufactured by:

  • Die casting, the part is made from a single piece of material indicating either machining of casting, and the geometries of this part to not require machining to be created

Function: Receives torque form crankshaft in order to drive the belt and thereby other tertiary systems

Amount: 1

Dimensions:

  • Height: 2.5 cm
  • Diameter: 16 cm

Associated Dissection Step: 20


Belt Tensioner Pulley

Part #: Illegible

Weight: 0.75 lb (all plugs and wires)

Materials: Steel

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/d/d3/Belttensionerpullyg14.jpg

The belt tensioner pulley is manufactured by:

  • Stamped wheel, due to its relatively thin thickness
  • Die cast body, evident by its rough surface finish
  • Extruded tube due to its constant cross-section
  • Lathed collar, evident by the visible circular grooves around the center of the part
  • Stamped and machined plate/impeller, evident by the overall thin thickness and intricate geometries

Function: Maintains tension on the timing belt in order to maintain the transmission of torque to the tertiary system. Redirects the timing belt to other systems.

Amount: 1

Dimensions:

  • Diameter: 8 cm
  • Height: 2.5 cm

Associated Dissection Step: 19


Chain Tensioner

Part #: none

Weight: 1 lb

Materials: steel, plastic

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/d/d0/Chaintensionerg14.jpg

The chain tensioner is manufactured by:

  • Injected molding, visible in the seam lines on the two plastic pads
  • Stamped casing and leaf spring, evident in the very thin and precisely bent shape of the parts

Function: Creates tension on the timing chain to maintain the transmission of torque between gears.

Amount: 1

Dimensions:

  • Base 1: 10.5 cm
  • Base 2: 5.5 cm
  • Side 1: 10.5 cm
  • Side 2: 11.5 cm

Associated Dissection Step: 35


Camshaft Pulley

Part #: 24574843

Weight: 2 lb

Materials: plastic, steel, aluminum

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/f/f9/Camshaftpullyg14.jpg

The camshaft pulley is manufactured by:

  • Multiple stamped plates, evident in their thin thickness and layered together
  • Injected molding, visible in the seam lines of the wheel and that it is made up of a hard plastic

Function: Maintains tension on the timing belt to better transmit torque between systems. Redirects the timing belt to other systems

Amount: 1

Dimensions:

  • Diameter 1: 7.5 cm
  • Diameter 2: 8 cm
  • Width 1: 3.5 cm
  • Width 2: 4.5 cm

Associated Dissection Step: 32


Distributor Timing Gear

Part #: 110401333101w

Weight: 1 lb

Materials: aluminum, steel, rubber

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/9/91/Distributortiminggearg14.jpg

The distributor timing gear is manufactured by:

  • Die casting, evident in the surface finish of the body, and the shaft
  • Milling, visible in the intricate geometries cut into the shaft
  • Injected molded O-ring, due to the seam line and pliable material
  • Stamping, evident in the separating plate's small thickness

Function: Receive camshaft and pass it to the distributor for mechanical timing

Amount: 1

Dimensions:

  • Largest Diameter: 3.5 cm
  • Smallest Diameter: 1.75 cm
  • Height: 13.5 cm

Associated Dissection Step: 38


Spring Gasket for Coolant Thermostat

Part #: 1809189

Weight: 0.25 lb (all plugs and wires)

Materials: steel, plastic, rubber

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/0/08/Springgasketforcoolantg14.jpg

The spring gasket is manufactured by:

  • Injection molding to form the gasket, evident but the seam line and rubber material
  • Two stamped metal sides, due to their thin thickness
  • Extruded core, due to its constant cross-section
  • Drawn wire, due to the visible spring surrounding the core with thin diameter

Function: Allows the engine to heat up to the proper temperature and then regulates the flow of coolant to maintain that temperature.

Amount: 1

Dimensions:

  • Largest Diameter: 4.5 cm
  • Smallest Diameter: 2.5 cm
  • Height: 4.5 cm

Associated Dissection Step: 17



=== Fasteners ===

Mounting Bracket

Part #: 41-948 25320502

Weight: 10 lb

Materials: steel or cast iron

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/5/5c/Mounting_bracketg14.jpg

The mounting bracket is manufactured by:

  • Die cast body, evident by rough surface finish
  • Drilled holes and threads, visible on the body

Function: Provides mounting for other systems that attach to the engine (i.e. alternator, water pump, etc.)

Amount: 1

Dimensions:

  • Length: 39 cm
  • Width: 17.5 cm
  • Thickness: 1 cm

Associated Dissection Step: 13


Distributor Mounting Bracket and Spacer

Part #: 24576136

Weight: 0.25 lb

Materials: aluminum

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/e/e6/Distributor_mounting_bracketg14.jpg

The distributor mounting bracket is manufactured by :

  • Die cast body, evident by rough surface finish
  • Drilled holes and threads, visible on the body.

Function: Mounts/Connects the distributor to the engine block

Amount: 1

Dimensions:

  • Side 1: 15 cm
  • Side 2: 6 cm
  • Side 3: 6 cm
  • Side 4: 6 cm
  • Side 5: 11 cm
  • Side 6: 6.5 cm

Associated Dissection Step: 14


Piston Clamps

Part #: none

Weight: 0.5 lb (each)

Materials: the clamp is most likely steel, the inner collar is aluminum

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/a/a5/Pistonclamps.jpg

The piston clamps are manufacture by:

  • Die casting with cutting, evident in the rough surface finish and circular saw marks
  • Drilling, the parts have multiple holes that would've been created by a drilling process

Function: Clamps the pitons to the crankshaft. The collar allow for lubrication (see manufacturing for details)

Amount: 4

Dimensions:

  • Outside Diameter: 8 cm
  • Inside Diameter: 5.5 cm

Associated Dissection Step: 28


Back Crankshaft Clamp

Part #: GM 25240

Weight: 2.5 lb

Materials: Steel

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/c/c8/Backcrankshaft_clamp.jpg

The back crankshaft clamp is manufacture by:

  • Die casting with cutting, evident by the rough surface finish and the circular saw cuts
  • Extruded aluminum covered that are pressed and rolled, evident by the constant cross-section with a center channel pressed into it and a curve added. This is done to lower expenses, it is easier to add an oil groove in a thin aluminum collar than to mill it into the piston clamp
  • Drilled holes, the part contains smooth holes through the part which would be best created by drilling

Function: Bolts to the block to hold the crankshaft in position

Amount: 1

Dimensions:

  • Outside Diameter: 13.5 cm
  • Inside Diameter: 6.5 cm
  • Thickness: 4.5 cm

Associated Dissection Step: 27


Crankshaft Clamps

Part #: none

Weight: 1.5 lb (each)

Materials: steel

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/6/6a/Crankshaftclampsg14.jpg

The crankshaft clamps are manufactured by:

  • Die casting with cutting, evident by the rough surface finish and the circular saw cuts
  • Extruded aluminum covered that are pressed and rolled, evident by the constant cross-section with a center channel pressed into it and a curve added. This is done to lower expenses, it is easier to add an oil groove in a thin aluminum collar than to mill it into the piston clamp
  • Drilling. The parts contain smooth holes through the part which would be best created by drilling

Function: Bolts to the block to hold the crankshaft in position.

Amount: 4

Dimensions:

  • Outside Diameter: 11.5 cm
  • Inside Diameter: 7 cm
  • Thickness: 2.5 cm

Associated Dissection Step: 23

The engine also has 100+ bolts, nuts, washers, and screws. These are all made of steel and are all different shapes and sizes depending on the component requires for fastening. In order to mass produce screws and bolts, steel rod is rolled in between two dies to produce the threads. If more accuracy is required the threads can be machined on a lathe. The threads in a nut are machined by drilling the hole with a tap.



=== Fluid Transfer Components ===

Coolant Tube

Part #: none

Weight: 1.5 lb

Materials: Steel

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/2/2b/Coolant_tube.jpg

The coolant tube is manufactured with:

  • Multiple extruded tubes which are welded together, shown in their constant cross-section and welding fillets
  • Stamped plates, evident in their small thickness
  • Injected molded fitting, due to visible seams and plastic material

Function: Transports coolant to the engine block.

Amount: 1

Dimensions:

  • Diameter: 4 cm
  • Length: 60 cm

Associated Dissection Step: 2


Fuel Rail

Part #: 17200924 DELPHI 00097

Weight: 1 lb

Materials: copper, plastic rubber, brass, aluminum

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/f/f0/Fulerailassemblyg14.jpg

The fuel rail assembly is manufactured with:

  • Multiple injected mold connectors, evident by the seams and plastic material
  • Multiple extruded and shaped tubing, seen in the constant cross-section with areas of bending
  • Multiple stamped fittings, evident in their low thickness and large quantity.

Function: Delivers fuel to individual cylinders.

Amount: 1

Dimensions:

  • Length: 36 cm
  • Hose length: 36 cm
  • Hose Diameter: 2 cm

Associated Dissection Step: 3


Intake Assembly

Part #: 12563051

Weight: 7 lb

Materials: plastic, silicon, aluminum, brass, rubber

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/3/33/Intake_assemblyg14.jpg

The intake assembly is manufactured with:

  • A large injected molded case, with visible seam lines and plastic material
  • A metal die cast core, evident by the rough surface finish
  • Extruded tubing, due to its constant cross-section
  • Extruded and machined fittings, evident by their constant cross-section and internal threads
  • Multiple stamped plates with thin thickness and identical shape
  • A drawing and bending, visible in a spring with thin wire and creating tension

Function: Evenly distributes the combustion mixture into each cylinder to obtain optimum efficiency.

Amount: 1

Dimensions:

  • Length: 37 cm
  • Height: 27 cm
  • Width: 28 cm

Associated Dissection Step: 4


Oil Filter

Part #: 2501074

Weight: 0.5 lb

Materials: aluminum, foam, rubber

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/c/c6/Oil_filterg14.jpg

The oil filter is manufactured with:

  • Injected molded O-ring, evident by the seam lines and plastic material
  • Injected molded center, due to plastic material and injection points
  • A stamped metal exterior, due to its low thickness
  • A stamped metal base, evident by its small thickness

Function: Removes contaminants from the engine oil.

Amount: 1

Dimensions:

  • Diameter: 7.5 cm
  • Height: 8.5 cm

Associated Dissection Step: 5


Dipstick Tube

Part #: none

Weight: 0.5 lb

Materials: plastic cover, aluminum tube

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/9/9f/Dipstick_tubeg14.jpg

The dipstick tube is manufactured with:

  • An extruded tube, evident by its constant cross-section
  • A stamped mounting plate, due to its thin thickness
  • Injected molded cap, evident by its plastic material and visible injection point
  • Rolled metal strip, due to its thin thickness and constant profile Function: Allows a user to check the oil level of the engine.

Amount: 1 Dimensions:

  • Diameter: 4 cm
  • Length: 40 cm

Associated Dissection Step: 7


Oil Pan

Part #: 156050

Weight: 6 lb

Materials: aluminum, rubber

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/d/d7/Oilpang14.jpg

The oil pan was manufactured by:

  • Stamped plates, as seen by their small thicknesses
  • The drilled, evident by the holes surrounding the rim of the pan

Function: Houses the motor oil that is transported to lubricate the engine. Holds the oil for the crankshaft “bath.” A magnet in the bottom of the oil pan also helps to isolate any metal contaminates from the rest of the oil.

Amount: 1

Dimensions:

  • Length: 37 cm
  • Height: 24 cm
  • Width: 17 cm

Associated Dissection Step: 21


Oil Pump

Part #: 10198830

Weight: 2.5 lb

Materials: aluminum, steel, plastic

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/5/5b/Oilpumg14.jpg

The oil pump was manufactured by:

  • Die casting with cutting of the body, which has a rough surface finish and circular saw marks
  • Extruded tube, which can be inferred by its constant cross-section
  • Stamped circle, evident by its very flat nature

Function: Pumps oil through passages in the engine to lubricate the systems that need it.

Amount: 1

Dimensions:

  • Max Height: 23 cm
  • Width: 13 cm
  • Length: 16.5 cm

Associated Dissection Step: 22


Exhaust Header Manifold

Part #: none

Weight: 10 lb

Materials: steel or cast iron

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/6/64/Exhaust_manifoldg14.jpg

The exhaust manifold is manufactured with:

  • Die cast body which is cut, evident by the rough surface finish and circular saw marks

Function: Directs the exhaust out of the engine. Houses the O2 sensor.

Amount: 1

Dimensions:

  • Side 1: 14 cm
  • Side 2: 30 cm
  • Side 3: 13 cm

Associated Dissection Step: 8


Black Mount for Coolant Thermostat

Part #: none

Weight: 0.25 lb

Materials: steel

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/d/d5/Blackmountforcollantthermostatg14.jpg

The black mount for the cooling thermostat is manufactured by:

  • Stamped plate, evident by its thin thickness and bent edges
  • Extruded piper, due to constant cross-section

Function: Acts as a flange connection for coolant intake. Houses the Spring Gasket for Coolant Thermostat.

Amount: 1

Dimensions:

  • Height: 4 cm
  • Top Diameter: 3.5 cm
  • Bottom Length: 9.5 cm
  • Bottom Width: 7.5 cm

Associated Dissection Step: 16


Silver Coolant Thermostat Housing

Part #: 24575473

Weight: 0.5 lb

Materials: aluminum

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/5/5a/Silvercoolantthermostathousingg14.jpg

The silver coolant thermostat housing is manufactured by:

  • Die casting and cutting, evident by the rough surface finish and the circular marks indicating a circular saw cut

Function: Acts a channel for coolant to flow trough. Houses the Spring Gasket for Coolant Thermostat.

Amount: 1

Dimensions:

  • Length: 18 cm
  • Diameter: 4.5 cm

Associated Dissection Step: 18



=== Electrical Components ===

Spark Plugs

Part #: 41-948 25320502

Weight: 1 lb (all plugs and wires)

Materials: porcelain, zinc chromate, aluminum, copper

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/6/65/Sparkplugsandwires.jpg

The spark plugs are manufactured with:

  • An extruded tube, due to its constant cross-section
  • An injected molded casing which is evident by the seams and plastic material,
  • This part is also heavily machined, evident by the intricate geometries that are present.

Function: Provides the necessary electrical spark to ignite the fuel air mixture within each cylinder.

Amount: 3

Dimensions:

  • Length: 7.5 cm
  • Diameter: 1.5

Associated Dissection Step: 1


Spark Plug Wires

Part #: none

Weight: 1 lb (all plugs and wires)

Materials: copper, rubber, plastic

The spark plug wires are manufactured with:

  • Injected molded covers which, is evident by the seams in the material
  • Extruded tubing, which is evident by the constant cross-section
  • And with what is assumed to be wire inside being drawn due to its thin diameter

Function: Transmits the electrical charge from the distributor to the spark plugs.

Amount: 3

Dimensions:

  • Length: 67 cm

Associated Dissection Step: 1


Distributor

Part #: 11040450D12

Weight: 2.5 lb

Materials: plastic, aluminum, cooper inside for wires

Phototgraph:http://gicl.cs.drexel.edu/wiki-data/images/e/e6/Distributor_mounting_bracketg14.jpg

The distributor is manufactures with:

  • Stamped base plate, evident by its small thickness
  • Injected molded casing, due to visible seam lines and plastic material
  • Extruded connecting points, due to constant cross-section

Function: Provides timed electrical impulses to the spark plugs, via the spark plug wires, to initiate fuel combustion

Amount: 1

Dimensions:

  • Length: 15 cm
  • Width: 13.5 cm
  • Height: 9 cm

Associated Dissection Step: 14



=== Covers and Housings ===

Valve Cover

Part #: 24577252

Weight: 2 lb

Materials: aluminum

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/4/4c/ValveCover.png

The valve cover is manufactured with:

  • Die cast body, due to the rough surface finish
  • Machining, due to the threaded holes
  • Injected molded gasket, with visible seam line

Function: Maintain pressure within engine and valve housing as well as prevent oil leakage.

Amount: 1

Dimensions:

  • Length: 34 cm
  • Width: 14.5 cm
  • Height: 4 cm

Associated Dissection Step: 9


Valve Housing

Part #: 24576144

Weight: 25 lb

Materials: aluminum

The valve housing is manufactured by:
Figure [1]: Lost Foam Cast Valve Housing
  • Lost foam casting (see Figure 1), evident by the unique surface finish
  • Drilling done, evident by the threaded holes on the housing






Function: House the valves that control to intake of fuel and air as well as the release of exhaust from the cylinders.

Amount: 1

Dimensions:

  • Length: 45 cm
  • Width: 15 cm
  • Height: 14 cm

Associated Dissection Step: 15


Push Rod Guides

Part #: 24575541

Weight: 0.25 lb (each)

Materials: plastic

The push-rod guides are manufactured by:

  • Injected molded, evident in seam lines and plastic material used

Function: Guide the push rods in a straight linear path.

Amount: 2

Dimensions:

  • Length: 15 cm
  • Width: 2.5 cm
  • Height: 5 cm

Associated Dissection Step: 30


Timing Gear Cover

Part #: none

Weight: 1 lb

Materials: aluminum

Photograph:http://gicl.cs.drexel.edu/wiki-data/images/3/3f/Timinggearcoverg14.jpg

The timing chain cover is manufactured by:

  • Die casting, evident in the plate's surface finish
  • Injected molding, visible in the gasket's seam line and pliable nature
  • Drilling, evident in the holes and threads places in the part

Function: Prevent contaminants and debris from entering the timing gear and timing chain.

Amount: 1

Dimensions:

  • Length: 30 cm
  • Width: 19 cm
  • Height: 2.5 cm

Associated Dissection Step: 34

Product Analysis

The product analysis will take ten of the more integral components of the engine and go into a more in depth analysis. Each component section will have the following: Part Number (if applicable), Component Function, Component Form, Manufacturing Methods, Component Complexity, The Associated Dissection Step (in reference to gate 2), and a picture of the component. Note: During the time period in which this engine was designed, global, environmental, and societal factors weighed very little on the design decisions in comparison to economic factors.

Component Function
The section describing the component's function will discuss the components primary and any secondary functions that the component may perform. The section will also discuss the primary transfer associated with the components main function. It is important to note that all the components in this section loose energy from heat generated by friction. The final thing that is discussed in the component function is the environment in which the component itself functions. Each components function, transfers, and environment can directly affect the other sections of this discussion (manufacturing, complexity, and form).

Component Form
This section will provide a bridge between a component's function and the shape and properties of that function. The section will go over the shape, symmetry, material, and aesthetic properties of the component, and tie that information back to the function that the component must perform. It is important to note that almost all of the components (with the engine block being the exception) are not visible while the engine is together and functioning. These components do not have any “beautifying” aesthetic properties. This section will also contain the approximate dimensions and weight of the component.

Manufacturing Methods
The creation of a particular part is done through many possible manufacturing processes. In many instances, a property of a component can be created through many different manufacturing methods. Which method is used can be effected by four many factors of design, environmental, social, global, and cultural. The methods used to create a piece can be figured out from characteristics of the part such as certain surface marks, materials used and shapes or geometries.

Component Complexity
For this section, component complexity will be defined by what the part does, the shape of the part and what goes into making the part.

A part whose function is of higher level, for example turning electrical energy into rotational energy, is a more complex part. As opposed to a part that may just act to hold to other components together is less complex.

For shape, a component that has a very intricate geometry, such as many asymmetries or possible multiple pieces in it, is a more complex part. Where a component that has regular geometries or multiple levels of symmetry is less complex.

The manufacturing process will also impact that over all complexity. If a part requires many processes to create, or processes that are difficult, that part will have added complexity. This compared to a part that may have a very simple manufacturing process which would then be less complex.

The scale used will work as follows:

  • The component's function can be rated from 1 to 3 in terms of complexity. 1 is a very simple function such as holding two other components together. Where 3 is a function that converts some operation from one to another, such as a motor creating rotational energy from electricity.
  • The component's shape can be rated from 1 to 3 in terms of complexity. 1 is a shape that contains multiple symmetries. 3 is a shape that has none or few symmetries.
  • The manufacturing that goes into a component can be rated from 1 to 3. Where 1 is a component that requires very inexpensive processes. And 3 is a component that requires an expensive process (expense coming from difficulty and time, which will imply complex).

Each component will have a number for each category determined then summed to find an overall complexity of the component.

For the complexity of component interactions, each component will be check to see which surrounding components it interacts with directly and then rated from 1 to 3 in complexity. In this scale, a 1 is a very simple interaction such as a static relationship between the two components with possibly some forces, such as a gear on a shaft where relative to each other there is no motion occurring (this example does not yet consider the interaction between the gear and another gear or chain). A 3 would have motion occurring between the two components and multiple forms of energy transfer between the two components.

Pistons

Figure [2]: Pistons

Part #: none

Piston Function

A piston’s primary function is to translate its linear motion, which is caused by the expansion of gases, to the crankshaft of the engine. As the piston strokes downward it is able to draw in air and fuel from the valves. This mixture is combusted further perpetuating the piston’s function. Pistons also perform of a secondary function of flushing the cylinders of the exhaust left from the combustion process. The upward stroke of the piston forces the remaining gases out of another valve. Both material flows (fuel, air, and exhaust) and energy flows (mechanical/kinetic energy) are associated with a piston’s functions. A piston works inside a confined cylinder under high pressure and high heat conditions. These conditions are part of the reason for the materials selected for the pistons composition.

Piston Form

The general shape of a piston is a cylinder (see Figure 2). The piston head is a cylinder allowing it to fit into the cylinder of the engine block. The piston head is then connected to the crankshaft via the piston rod. The bottom of the piston rod is a half circle; this circular geometry accommodates the rotational motion of the crankshaft.

The piston has two different vertical symmetries 90 degrees apart from each other. These symmetries are partial due to the cylindrical shape of the piston head. The symmetry of the piston head gives insight into the method of manufacturing used to create it (i.e. machining). The piston is primarily 3 dimensional. This is to allow for a volumetric space in which the piston can function as well as allow for the combustion and expansion of gases within the cylinder, which houses the piston.

The cylindrical shape of the piston head is to allow for the most volume within the cylinder itself with the least amount surface area on the sides of the piston head. The smaller surface area and cylindrical shape allows for an even distribution of forces on the sides of the piston head. The circular shape at the end of the piston rod allows the crank shaft to freely rotate within the connection of the piston and crankshaft. If this connection was not circular the crankshaft would not be able to complete a rotation.

The piston heads are aluminum along with the collars. The piston rods are iron, and the axel in the piston is steel. Iron is chosen for its strength as well as its manufacturability (see manufacturing). Aluminum is chosen for the piston head because it’s light, which would lower the inertia of the piston. Aluminum also cools very quickly which can beneficial as for the piston id firing under extreme heats due to the combustion in the cylinder. The reasons these materials are chosen from a manufacturing standpoint will be discussed in the manufacturing section. The main factor affecting the material choice is economics, which is also discussed in the manufacturing section.

The pistons have no particular color besides the color of the material they are made of (aluminum being grey and iron rusting to a brownish color). The color, therefore, only alludes to the material of the piston. The pistons have no aesthetic purpose as they are contained within in the block and cannot be seen while the engine is functioning. The piston head and the collar both have a rather smooth finish this allows lower the friction between the cylinder and the crankshaft respectively. The surface finish is merely functional.

Dimensions:

  • Piston Head Diameter: 9 cm
  • Piston Head Height: 5.5 cm
  • Total Height: 18 cm
  • Diameter of Collar: 8 cm

Weight: 2.5 lb

Piston Manufacturing

The pistons are components with multiple pieces used in forming them. At the top of the piston there is a piston head with rings for sealing the compression chamber. Below the piston head is the connecting rod which is needed in attaching the piston head to the crankshaft and is held to the piston head with an axle.

The processes of manufacturing are likely as follows:

  • The head of the piston would be first created with a casting and cutting (flashing removal) process. After this rough shape was made it would be lathed down and then milled and finally drilled. The piston head's shape and required strength would be best accomplished by casting. While milling could achieve this as well, it would be excessive considering the lathing and milling that already takes place. The piston's lathing is evident in the circular grooves along the heads surface and the constant indents in the piston's side created for the piston rings. Very consistent sections are removed from the piston on the side in a non-axial symmetric way, which shows milling was likely used. Finally, the precise hole required for the connecting rod axle would be drilled. The aluminum head prevents a grinding process from being used to create smooth surfaces which forces other processes to be employed.
  • The axle that the piston head and rod pivot around would be extruded. The malleable steel used in its creation and its shape allow for extrusion to be the best manufacturing method available as well as give the steel a smooth surface finish to decrease friction.
  • The connecting rod is created by casting and cutting (flashing removal), and drilling. The bulk of the part would be formed by casting to create a piece strong enough to withstand the forces involved, and the required shape for use. The use of iron would make casting a better choice of manufacturing process to give the rod high strength. At the rod's base where it connects to the crankshaft, two holes are drilled and a thread is cut into the inside of the holes.

The main factor affecting the creation of the piston, again, is economic. The processes used are chosen for their overall cost. Casting and some machining process are used to get the precision where needed but it is a goal to make the parts as cost effective as possible.

Piston Complexity

  • Due to a piston's over all function of turning linear motion into rotational motion (in conjunction with the crankshaft) as well as compress gas in the chamber, its function complexity is a 3.
  • The shaping of a piston gives it a bilateral symmetry and a shape complexity of 2.
  • The multi-step and expensive processes that go into creating a piston give it a manufacturing complexity of 3.

Overall component complexity = 8

The interactions of the reciprocating pistons, with the cylinder walls in the form of friction and the crankshaft, are all forms of motion and energy transfer. This gives the pistons a component interaction complexity of 3.

Associated Dissection Step: 29

Crankshaft

Part #: none

Crankshaft Function

The crankshafts primary function is to turn the mechanical energy it receives from the pistons into rotational motion. The rotational motion generated by the crankshaft is transmitted to the transmission and from there into the drive shaft and the wheels of the vehicle the engine is powering. The rotational motion of the crankshaft is also transmitted to multiple other systems on the engine. The rotation and torque is transmitted to the camshaft by the timing chain and gears. The rotation and torque is also transmitter to systems like the alternator, water pump, etc. by the timing belt. The transmission of the crankshaft’s torque and rotational motion helps to perpetuate the function of the engine and by virtue the function if the crankshaft itself. The primary flow associated with the crankshaft is the transfer of mechanical energy by rotational motion/torque. The crankshaft is also associated with the transmission of signal. A notch or window on the crankshaft is read by a sensor to determine the engine rotations per minute. The crankshaft functions in a closed environment. It rotates in a bath of oil that helps to lower friction as well as remove some of the heat from the components of the engine.

Crankshaft Form

From the side the crankshaft is roughly shaped like a sine wave. If rotated 90 degrees along an axis down its length, the crankshaft all of the weights and connection points lie in a straight line down a central axis. All the connection points on the crankshaft are cylindrical. The crankshaft is mostly asymmetrical. Any symmetries are contained to small sections of the crankshaft, and most of these sections are the cylindrical connection points. The crankshaft as a whole is three dimensional

The crankshaft’s shape is largely coupled to the function it performs. The sine wave live shape is due to the offsetting of the piston connection pints on either side of the central axis. These offsets are what allow the crankshaft to be rotated of “cranked” by the pistons as the stroke upward and downward. The other asymmetries in the shape of the crankshaft are due to the weights on the crankshaft that also aid in maintaining the rotational motion.

The crankshaft is made of iron for the weight and durability of the material. The constant torque, force, and heat that the crankshaft endures requires it to be made of a sturdy material. Iron is also quite heavy. The extra weight of the iron means it takes more force to get it moving (a lighter force taking less force to get moving of course), but this also benefits the engine as for iron will remain in motion as for it is heavy and requires more force to stop it. See the section manufacturing to find out how materials may have affected the manufacturing process of vice versa. Iron is relatively heavy, cheap, obtainable, and abundant; therefore economics influences the choice of material the greatest.

The crankshaft has no purposeful aesthetic properties as for it is housed within the engine and is not visible while the engine functions. The aesthetic properties such as color and finish merely allude to the material, manufacturing, and functionality of the crankshaft. The smoother shiner finishes on the connection points of the crankshaft are to cut down on friction between it and the piston. The rougher finish of the rest of the crankshaft is a result of the manufacturing process used on it. See the section on manufacturing for more information in this. All the aesthetic properties of the crankshaft are functional.

Dimensions:

  • Length: 46 cm
  • Diameter at Widest Point: 15 cm

Weight: 40 lbs

Crankshaft Manufacturing

The crankshaft of the engine is probably one of the more recognizable and well know parts of an engine, especially to an average user. However, the intricacies of this part can be lost on a normal observer.

The manufacturing processes that go into its creation are likely as follows:

  • This single component, and its convoluted shape, was die cast in a mold to form the overall shape of the crankshaft. After this casting, a lathing and grinding process is used to create round contact points with very fine surface finishes. This step would be more complicated than the normal lathing and grinding processes because the points on the crankshaft that the pistons clamp onto are off center and the crankshaft cannot be rotated around these points with its shape causing improper balance. This would mean another form of lathing or grinding would need to be used with the head rotating around the part. The center contact points of the crankshaft, where it is held onto the engine block, are at the center and the part can be rotated around these sections. On one end of the crankshaft, special milling would go into the part due to a slot for a keyway. There are also very shallow drill marks at certain areas on the crankshaft, in particular the heavier sections that act to counterweight the pistons. These conical divots are likely a machining result from balancing the crankshaft. The part is likely spun to test its balance, and if it does not rotate smoothly, any weight causing the off balance will be removed by this drilling. Most of the exterior of the part has a rough finish and imply some form of casting, either a die with a rough interior or sand casting. This method allows for a strong and seamless rough shape to be made from iron which can be work into the proper product. The contact points on the crankshaft show very, very fine lines about their rims, they are likely from lathing or grinding. The choice of iron for this part allows many highly precise manufacturing methods to be used, due to the strength of iron.

Again, like many of the components in the engine, the individual part and the manufacturing processes that went into it focus on keeping cost down and are a result from economic factors. Iron becomes a material of choice for its strength and low cost. And the overall shape is formed in a single process of casting for lower cost.

Crankshaft Complexity

Due to the crankshafts over all function of turning linear motion into rotational motion (in conjunction with the crankshaft) its function complexity is a 2.

The shaping of the crankshaft gives it very intricate geometries and what would appear to be no forms of complete symmetry giving it a shape complexity of 3.

The multi-step and expensive processes that go into creating the crankshaft give it a manufacturing complexity of 3.

Over all component complexity = 8

The interactions of the crankshaft, with the pistons and the engine block have changing motion and energy transfer. However, there are multiple components mounted on the crankshaft that to not move relative to it. This gives it an overall component interaction complexity of 3.

Associated Dissection Step: 37

Harmonic Balancer

Part #: none

Harmonic Balancer Function

The harmonic balancer’s primary function is to dampen the vibrations created by the crankshaft. The harmonic balancer simply connects to the end of the crankshaft, and by virtue of its mass it dampens the vibrations of the crankshaft. The harmonic balancer found on the GM 4 cylinder engine that is the subject of this project, also connects to a belt pulley and helps translate torque to the engine belt. The harmonic balancer helps translate mechanical energy in the form of torque. It also helps to eliminate the transfer of unwanted mechanical energy that my come from vibrations caused by the crankshaft. The harmonic balancer functions in a relatively open environment. Exposure to outside elements should have little to no affect on its function.

Harmonic Balancer Form

The harmonic balancer is a stout, hallow, semi-tapered, cylinder with three evenly space connection points that branch off the front of it. If the keyway is to be included in analyzing the symmetry of the harmonic balancer, then there is only one bilateral symmetry along a axis that slits the keyway in half. If the keyway is neglected as for it would be added after all the initial symmetry is manufactured (see manufacturing for more details) the harmonic balancer can then be said to have one axial symmetry through the center of the hollow inside cylinder and three bilateral symmetries bisection the harmonic balancer similar to the symmetries of a triangle. Beside the keyway the other most notable feature of the harmonic balancer is its weight, which is its sole purpose for existing. The weight of the harmonic balancer along with is axial symmetry, which means its center of mass lies somewhere on the axis (again ignore the negligible amount of mass removed for the keyway). This property aides the harmonic balancer in performing its function of dampening the vibrations of the crankshaft as it rotates along the same axis that the center of mass lies on.

The harmonic balancer is made of iron. The material choice is impacted by the function of the component primarily on the fact that iron is a heavy material. See the manufacturing section on how the material choice affects the manufacturing of the harmonic balancer of vice versa. Iron is relatively heavy, cheap, obtainable, and abundant; therefore economics influences the choice of material the greatest.

The aesthetic properties of the harmonic balancer merely alludes to the material, manufacturing and connection method used. The grayish color alludes to the harmonic balancer being composed of some sort of metal, in this case iron as previously discussed. The exterior and interior finishes allude to the manufacturing process used to create the harmonic balancer (see the manufacturing section for more details). There is notable symmetry, which has been discussed previously. The other notable aesthetic property is the keyway. The presence of a keyway implies that the harmonic balancer is friction fir (as opposed to being threaded). The smoother interior finish also supports this claim as for it would allow for ease of assembly or disassembly by cutting down on friction as well as having a tighter fit. The aesthetic properties of the harmonic balancer are functional.

Dimensions:

  • Inside Diameter: 4 cm
  • Outside Diameter: 6 cm
  • Height: 7 cm
  • Point to Point: 8 cm

Weight: 2 lb

Harmonic Balancer Manufacturing

At one end of the crankshaft is the harmonic balancer. Its existence is integral to the operation of the engine, as it helps dampen out vibrations in the engine.

The manufacturing processes that go into making it are likely as follows:

  • The harmonic balancer was cast to get its rough shape. After casting and cutting (flashing removal), one face was lathed down to a roughly flat surface. The 4 holes in the piece, (one in the center and three others surrounding the center) could be placed in the cast but due to other features were likely machined. Each of the three outer holes were drilled and machined, where the central hole was drilled and broached. These processes are supported by the fact that iron was used, which lends itself to being cast and machined. On the harmonic balancer's one side there is a constant spiral groove which is a very good indication of some form of lathing. Also, the out surface has a rough finish often caused by some form of casting such as sand casting. The three outer holes are threaded which would require drilling and machining, where as the central hole is very smooth and contains a keyway which would be made with drilling and broaching.

The main factor effecting the creation of the harmonic balancer, again, is economic. The processes used are chosen for their overall cost. Casting and some machining processes are used to get the precision where needed but trying to make as many parts as possible as cheaply as possible is an important goal. Harmonic Balancer Complexity

Due to the harmonic balancer's simple function of, to be blunt, have mass which in turns aids in dampening vibrations, its function complexity is a 1.

The shape of the harmonic balancer gives it an axial symmetry as well as multiple bilateral symmetries, giving it a shape complexity of 1.

The brief creation processes that go into the harmonic balancer, with a noting of the lathing that occurs, gives it a manufacturing complexity of 2.

Overall component complexity = 4

The harmonic balancer, which is mounted on the crankshaft and then has a pulley mounted to it, sees no motion relative to the parts around it. This gives it a component interaction complexity of 1.

Associated Dissection Step: 33

Timing Chain

Part #: none

Timing Chain Function

The timing chain’s primary function is to translate the rotational motion and torque of the crankshaft to the camshaft. The timing chain is connected to a smaller gear on the crankshaft to a larger gear connecter to the camshaft. The ratio of these gears allows the chain to translate the proper torque and speed to allow the engine to function in harmony. The timing chain is primarily associated the transfer of mechanical energy in the form of rotational motion/torque. The timing chain functions in a relatively closed environment shielded by the timing chain assembly cover, which prevents debris from getting caught up in and damaging the assembly.

Timing Chain Form

Describing the shape of the timing chain is difficult without using the word “chain” in the description. The timing chain consists of multiple links. Each individual link is comprised of multiple flat pill shaped pieces that are stacked together. Two adjoining links alternate staking so the chain links are stacked in such a way that there is space left for the gear teeth to fit in each link (the effect of this being the space in each link that one can see through). This shape allows the timing chain to fit over both the timing gear and the gear at the end of the crankshaft. It may sound redundant, but the timing chain is shaped like a chain because it needs to be a chain. To accurately transfer the timing need from the crankshaft to the camshaft, a gear system is needed, and a chain is needed to bridge the gap between gears. The alternative would be a belt and pulley system, but such a system would be subject to slippage and most belt materials are more commonly subject to deformation. On that note it can be determined that a chain in the shape of chain is needed to perform the task of a chain. (Note: this applies only to the engine of this case and study, and other engine may use different systems).

Due to the fact the timing chain is composed of multiple links, each being symmetrical, and that the chain is only able to bend around one axis, it can be said that the chain is symmetrical along the axis which it cannot bend around. Much of the timing chain’s symmetry is dependent on the gear it is interacting with. The timing chain does not need to be symmetrical to function, but on this particular engine by virtue of the gears it is interacting with the timing chain is symmetrical. The timing chain is primarily three dimensional because the teeth of the gears that it interacts with are three dimensional.

The timing chain is comprised of steel. Steel was chosen because of its strength and durability. Steel was chosen as opposed to iron due to is increased strength and lighter weight, which will lower the amount of force required to begin moving the chain. As previously mentioned, a chain was chosen over a belt most likely due the materials of a belt more commonly deforming. Therefore, the chain requires a more durable material, steel. See the section on manufacturing for any information on how the material may have affected the manufacturing process of vice versa. Steel is relatively, cheap, obtainable, and abundant and it meets the requirements of the system; therefore economics influences the choice of material the greatest.

The timing chain has no aesthetic purpose. Its aesthetic properties only allude to the material and the manufacturing process used in creating the component. The silver grey color gives indication that the timing chain is made of some sort of metal, in this case steel as already stated. The smoother surface is to cut down on friction between adjoin links and friction with the gears that the timing chain is interacting with. The aesthetic properties of the timing chain are merely functional.

Dimensions:

  • Length of Whole Loop: 56 cm
  • Width: 1.5 cm
  • Thickness: 0.5 cm

Weight: 2 lb

Timing Chain Manufacturing

From the timing gear to a smaller gear mounted on the crankshaft, runs the timing chain. This flexible part is used to transmit torque from the crankshaft to the timing gear. The piece itself can be broken done into two main parts. There is the axle component that a linkage pivots about and s flat component that hinges around the axle piece.

The processes of manufacturing are likely as follows:

  • The links are formed in a stamping process. A magnetic metal, likely steel, is stamped and punched from a plate to create a flat link with two holes in it at either end. The shape, or more specifically the small thickness of the links and their large number, even for a single engine, means that they would try to be created in higher volume which a stamping process would best accomplish. The use of steel, and its malleable properties, allows for stamping and punching to be used without warping or damaging the shape.
  • The 'axle' component would be drawn steel rod which is then pressed to flatten one end. After the links are added the other side would be flattened in a riveting style process. This can be seen by looking at the ends of the axle components which appear to have been cut and then compressed, which would be easily and cost effectively done by drawing the thin rod, cutting, and flattening. Also, the axial symmetry of the rods would allow for drawing to be very easily done. The use of steel, and its malleable properties, allows for drawing to be used without breaking the axle piece.

Of the four factors, the most applicable to the manufacturing processes here is economic. The chain just could have easily been made with thicker links that are fewer in number, but this would make stamping more difficult and other process for cutting the links would and drilling the holes would be more expensive even if they used less material. The drawing process, or possibly extrusion, for the axle component would be used to very quickly make the needed pieces at a speed that other processes wouldn't be able to match.

Timing Chain Complexity

Due to the timing chain's overall function of transmitting torque over some distance perpendicular to the torque, its function complexity is a 2.

The shape of the chain poses a brief challenge in that it is flexible in many, many degrees. To counter this, the shape complexity will consider a single linkage assembly (which is then repeated to create the entire real chain). A linkage has multiple areas of bilateral symmetry, giving it a shape complexity of 2.

The overall simple manufacturing processes that go into making the chain (stamping, extruding and pressing, all fairly basic) give it a manufacturing complexity of 1.

Over all component complexity = 5

The timing chain, which has an interesting motion relative to the gears it runs on. Where a single link does not see motion relative to the gear tooth it rests on. There is a transmission of energy from one portion of the chain to another, giving it a component interaction complexity of 2.

Associated Dissection Step: 36

Timing Gear

Part #: GM10198810

Timing Gear Function

The primary function of the timing gear is to transmit the torque and rotational motion received from the timing chain via the camshaft, to the camshaft. The ration of the timing gear to the gear on the crankshaft allows the timing gear to transmit the proper speed to the camshaft to allowing the engine to function in harmony. The timing gear is primarily associated with the transfer of mechanical energy in the form of rotational motion/torque. The timing gear functions in a relatively closed environment protected by the timing chain assembly cover. The cover prevents debris from entering the timing chain and timing gear, and possibly damaging or interrupting the assembly’s function.

Timing Gear Form

The timing gear can be described as short cylinder. It has numerous teeth around its edge that interact with the timing gear. If the keyway is taken into account the gear has one bilateral symmetry (ignoring the one small circular hole) that cuts it into two semicircles down the center of the keyway, and one axial symmetry through its center. If the keyway is ignored as for it would be added after most of the symmetry is already present (see manufacturing for more on this) then the timing gear has three bilateral symmetries each cutting the gear into two semicircles and bisection one of the three elongated holes (this is again ignoring the one circular hole). The timing gear is relatively flat in comparison to the overall diameter of the gear and is therefore as a whole is primarily two dimensional (though it should be noted the teeth on a smaller scale are three dimensional).

The circular shape and the symmetry of the gear are coupled to its rotational function. The relative “flatness” of the gear helps to cut down in the space in which the gear functions. The three elongated holes in the gear are primarily to cut down on weight and may, secondarily, redistribute some forces.

The timing gear is made of iron. Iron is chosen primarily for its strength as well as its malleability. See the manufacturing section for more on how the material choice impacted the material and vice versa. The gear is exposed to extreme heat as well as constant torsion while the engine is running and the material choice needs to be able to withstand these conditions. Iron is relatively heavy, cheap, obtainable, and abundant; therefore economics influences the choice of material the greatest.

The primary aesthetic properties of the engine allude to the material choice, the function, the connectivity, and manufacturing of the timing gear. The gear has no aesthetic purpose as for it is not visible while the engine is operating. The timing gear is a particular grey which implies that the gear is most likely made of some sort of metal. The finish on the timing gear is linked to the manufacturing process used to create it (see manufacturing for more). The teeth along with the keyway give evidence to the gears interaction with other components of the engine. The teeth indicate that the gear fits to the timing chain to either transfer or receive torque. The keyway indicates that the timing gear is friction fit as opposed to threaded etc. A Friction fit involving a keyway implies the part is involved in a lot of rotation. Threads have the possibility of unscrew in the part it under too much torque or rotation, this makes a friction fit with a keyway a wiser choice. The aesthetic properties are primarily linked to the components functionality.

Dimensions:

  • Outside Diameter: 12 cm
  • Inside Diameter: 2 cm
  • Height: 1 cm

Weight: 2.5 lb

Timing Gear Manufacturing

Mounted on one end of the camshaft and being driven by the timing chain is the timing gear. This component takes the torque delivered by the chain to rotate the camshaft and the correct rpm for opening the valves above the pistons.

The processes of manufacturing are likely as follows:

  • The gear's overall form would be cast . After casting, the flat faces of the gear would be lathed down to achieve a flat surface finish. Then the out edge of the gear would be milled to create the gear teeth. With the gear's rough finish on sections that are not machined, as well as it's constant cross-sectional shape, it is likely die cast. Each side of the gear has a groove about its axis which points towards a lathing process. The gear teeth themselves would be most easily machined down due to the precision needed and the intricate shape. These manufacturing processes are possible due to the iron in the gear. Had another softer material been used, these high precision processes would not achieve tolerances as iron.

The single largest factor type affecting the manufacturing processes are the economic factors. Again, this is seen in the choice of material, which in this case is iron, chosen to for its malleability, strength, and lower cost compared to alternatives such as certain steel types. Interestingly the gear's shape has a constant cross-section which creates the question, why not extrude the gear? While the process may be possible, multiple issues would arise that would increase cost of the gear's life. Firstly, there is a risk to the precision in the gear as well as strength. The amount of material per gear would also be greater. If these costs were still cheaper, over the life of the gear, damage from poor precision or breaking due to lower strength would also raise the total cost.

Timing Gear Complexity

Due to the timing gear's simple function of applying the timing chain's torque into the camshaft, its function complexity is a 1.

The shape of the timing gear gives it many, many bilateral symmetries as well as an axial symmetry, giving it a shape complexity of 1.

The manufacturing processes that go into making the gear, however, are very time consuming (e.g. lathing, cutting teeth), giving it a manufacturing complexity of 3.

Over all component complexity = 5

The timing gear does not see any motion relative to the chain or camshaft but does apply a force to the camshaft, giving it a component interaction complexity of 2

Associated Dissection Step: 36

Camshaft

Part #: 101012HB1

Camshaft Function

The camshafts primary function is to translate receive the torque/rotation from the timing chain assembly, and translate that rotation in to properly timed linear motion. The rotation of the camshaft causes the individual cams along the shaft to interact with the push rod seats at established intervals. The camshaft also times the distributor via a gear on one end if the camshaft. The camshaft is primarily associated with the transfer of mechanical energy either by passing rotational motion on to a system that will act in a linear fashion or by transmitting rotational motion/torque to the distributor timing gear. The camshaft is also associated with the transmission of signal. A notch or window on the camshaft is read by a sensor to determine the engine rotations per minute. The camshaft functions confined within the engine block operating within a lubricated environment. Because it is in the block, the camshaft will also be exposed to extreme heats.

Camshaft Form

The camshaft, in essence, can be described as a long thin cylinder. The camshaft in actuality is comprised of a number of shorter cylinders and cams (a cam being an almost tear drop shaped cylinder) staked together in the general form of a longer cylinder. Overall the camshaft has no symmetries mainly because it performs its function with asymmetry (i.e. the cams). The camshaft is primarily three dimensional. The overall cylindrical shape of the camshaft is primarily linked to the camshaft having to rotate in order to function. The individual smaller cylinders that make up the “stack” are what rest on point within the block keeping the camshaft rotating in place. The shape of the cams changes at a particular point as the whole camshaft rotates guiding the push rod seats up and down.

The camshaft is made of steel. Steel is chosen for its durability. The camshaft needs to be made of a material that can withstand the heat it endures in the engine as well as the constant wear and torsion in the camshaft. Steel has the proper attributes to allow the camshaft to successfully perform its function. See manufacturing for information on how the material choice affects the manufacturing of the camshaft and vice versa. Steel is relatively, cheap, obtainable, and abundant and it meets the requirements of the system; therefore economics influences the choice of material the greatest.

The most prominent aesthetic properties of the camshaft are the color and the finish. The color being a silver grey alludes to the material of the camshaft, steel. The finish of the camshaft is functional only. The smooth finish is to cut down on friction between camshaft and the engine block as well as the camshaft and the pushrod seats.

Dimensions:

  • Largest Diameter: 4.5 cm
  • Length: 42.5 cm

Weight: 10 lb

Camshaft Manufacturing

The camshaft of the engine stands as a very interesting component. A broad spectrum of manufacturing processes went into its creation. To begin, the camshaft is made of multiple pieces mainly consisting of a tubular shaft with cams, circular weights/resting points, and a helical gear attached.

The processes of manufacturing are likely as follows:

  • The main shaft is an extruded tube that was then cut at both ends. This is supported by the fact that the shape of the shaft has an axial symmetry about which it could be extruded. Also there are cut marks at the exposed end of the shaft meaning it was separated from another section of tubing. The material, likely to be iron, would allow these processes to be used due to its malleable properties. Over all, only a few materials would work well for the machining required for all the parts of the camshaft and price narrows down the selection further making iron the material for choice.
  • The circular weights/resting points would likely have been cast then lathed to achieve tight tolerances. The sides have fine grooves in them which support the idea of having been tooled on a lath. Also, like the shaft, their shape has axial symmetry allowing it to be mounted on a lath. The highly polished outer edge of the weights imply that at some point they were finely ground before finishing. Like the shaft, these processes would be possible due to the iron used in making the raw part. A softer metal, such as aluminum would not work with these manufacturing methods.
  • The helical gear’s manufacturing would likely be similar to the weights. It would have been cast then turned on a lathed. Additionally, it would be finely machined on a mill to add the helical cuts for gearing. Like the weights, the gear has fine grooves along its sides supporting the idea of being lathed. Interestingly, the peaks of the gear teeth show the same grooves which means the grinding step was likely omitted. The intricacy of the shape of the gear and gear teeth only allow for a highly precise milling machine, likely CNC, to complete the task of making the gear.
  • The cams on the camshaft are very precise parts that are created separately then attached to the camshaft. These pieces are likely cast in a raw form which is then machined down to a close approximate shape which then has the outer edge ground to a very fine surface finish. Die casting the raw part would be one of the simplest solutions to create a large number of them. After the raw cam is created, heavy machining would bring it to its final shape. This would include milling, drilling and grinding to achieve the required high precision. This is evident by the grinding marks on the exterior edge and very sharp angles on the part. The grinding is of particular interest due to the shape of the cams. Grinding the cams requires a device, a cam grinder, which uses a master cam which is a larger version of the desired cam and shifted the movement of a grinding head which will take the rough cam and smooth it to exact dimensions.

Economic factors, by far, impact the choices made the most. Every manufacturing process aims to reduce cost as much as possible. The shaft of the camshaft is extruded, allowing for many to be created with relative low cost. Many of the high precision parts are done in the lowest costing manner available, though much of the milling and machining still comes at great expense. A point can be made for other factors, that a material such as iron was used over steel due to end product price which is determined by what a target society is willing to spend. And that certain resources are too rare to be worth the cost of acquiring. Both these global and societal factors end up affecting the choice made in a way related to economic.

Camshaft Complexity

Due to the camshaft's over all function of turning linear motion into rotational motion (in conjunction with the push rod seats) its function complexity is a 2.

The shape of the camshaft, with numerous profile changes, offers no ways of creating over all symmetry, giving it a shape complexity of 3.

The manufacturing processes that go into making the camshaft give it a manufacturing complexity of 3.

Overall component complexity = 8

The camshaft interacts with the push rod seats as well as the timing chain. Constant rotational motion and its energy is transferred to the push rod seats. This gives it a component interaction complexity of 3.

Associated Dissection Step: 39


Pushrod Seats

Part #: none

Pushrod Seats Function

Figure [2.1]: Rocker Arm connected to camshaft


The primary function of the pushrod seats is to work in compliance with the camshaft to translate the camshafts rotational motion in to linear motion. The guide wheel at the bottom of the pushrod seat “rides” along the shape of an individual cam on the camshaft (as shown in figure 2.1) effectively moving up and down in a linear fashion as the cam rotates. This linear motion is then transmitted to the pushrods. The pushrod seats are primarily associated with the transfer of mechanical energy by converting the rotational motion of the camshaft to linear motion. The push rod seats function within the block inside individual cylinders, because they are within the block the pushrod seats can be under extreme heats while engine is functioning. They function under constant lubrication.

Pushrod Seats Form

The general shape of the piston rod seats is a cylinder. The cylindrical shape allows for the most even distribution of forces on the sides of the pushrod seats as they move up and down in their individual cylinders. The push rod seats have some symmetry and have three dimensions by virtue of their cylindrical shape. Other notable properties of the push rod seats are the divots at the top and the sideways cylinders at the bottom. The divots provide a seat for the push rods to sit in; the inverted cone shape of the divots keeps the push rods centered in the push rod seat. The sideways cylinder at the bottom of the pushrod seat acts as a roller. The roller rolls along the shape of the cam helping guide the push rod seat up and down as well as lowers the friction between seat and the camshaft.

The pushrod seats are made of steel. Steel is chose for its strength as well as its ability to be machined accurately (see manufacturing for more on the material choice of steel). Steel can with saran the forces that pushrod seats endure as well as the extreme heat of the engine. Steel is relatively, cheap, obtainable, and abundant and it meets the requirements of the system; therefore economics influences the choice of material the greatest.

The color of the pushrod seats merely alludes to the material used for the pushrod seats. The gray color of the seats implies that the pushrod seats are possibly metallic in nature. The main aesthetic property of interest is the finish of the pushrod seats. The seats have a very smooth finish to reduce the friction on the seats both between the block and the seat and the roller and the camshaft. The aesthetics of the pushrod seats are only related to their function.

Dimensions:

  • Diameter: 2 cm
  • Height: 5.5 cm

Weight: 0.5 lb (each)

Pushrod Seats Manufacturing

In order to turn the rotational motion of the camshaft in to linear motion, a small part called a pushrod seat is used. These small cylindrical components are pushed up and down by the cams and create a purely linear motion. The components themselves have multiple parts within them, which can be deceptive due to their small size.

The processes of manufacturing are likely as follows:

  • At the bottom of the pushrod seat there is a small cylindrical bearing. The bearing can freely rotate as a cam rolls against it. This piece would most likely have been extruded and then ground to a precise tolerance. The objects shape is the main supporter of this, with axial symmetry extruding this part would be the fastest way to accomplish it. The very smooth surface finish for lower friction indicates grinding was used. This cylindrical bearing can be ground to a smooth surface finish because of the use of steel as its material.
  • Within the pushrod seat there is a spring that keeps the cylindrical bearing pressing against the bottom of the push rod seat and acts to smooth the motion between the bearing and the cam. This spring, while difficult to see, is formed from wire. The wire is likely manufactured by a drawing process. After being drawn the wire is likely shaped and formed into a helix with some form of tempering involved to give it a greater elasticity. The spring's thin diameter, coiled shape, and malleable metal material support the idea that a drawing process was used.
  • The main body of the pushrod seat is completely symmetrical about its long axis. Along with this, the end that the push rod sits in is a hemispherical shape indent and the outside of the body has a changing profile. These shapes support that the push rod seat was likely extruded first. After a blank cylinder was formed it could be compressed to add strength as well as create an internal cavity for the spring and bearing. It would then be placed on a lath to create the changes in the part's profile and the indent. The exterior and the indent would then be ground to correct tolerances, evident by the fine surface finish.

This component is under the same circumstance as the others, the largest factor in its creation is economical. It is most desirable by the manufacturer to create the part as cheaply as possible, and the cheapest methods available can be chosen independent of global, societal, and environmental. While an argument can be made that watching that not too large a strain in resource consumption is placed on the environment or global interactions, these end up being accounted for within the economic factors.

Pushrod Seats Complexity

Due to the function of a push rod seat to turn rotational motion into linear (in conjunction with the camshaft) its function complexity is a 2.

The shape of a push rod seat does offer bilateral symmetry giving it shape complexity of 2.

The overall manufacturing processes that go into making a push rod seat give it a manufacturing complexity of 3.

Over all component complexity = 7

A pushrod seat moves in a linear motion receiving energy from the camshaft and transmitting it to a push rod, giving it a component interaction complexity of 2.

Associated Dissection Step: 31

Pushrods

Part #: none

Pushrods Function

The primary function of the pushrods is to receive linear motion from the pushrod seats and transmit that linear motion to the rocker arms. The linear motion of the pushrods actuates the rocker arms. The pushrods are primarily associated with the translation of mechanical energy in the form of linear motion. The pushrods function in a closed environment under constant lubrication. The push rods are under constant stress and heat while the engine is functioning.

Pushrods Form

The pushrods are long thin cylinders that have a small spherical bearing on either end. The push rods have axial symmetry along an axis down their length as well at bilateral symmetry (essential being able to be cut into two shorter rods). The push rods in reality are three dimensional, but in essence they are a one dimensional straight line. The push rods act long there length (in one dimension) transferring force to the rocker arms. As long as the forces that the push rod is transferring are parallel to the length of the rod, then it can endure fairly high loads by nature of its shape. The bearings at either end of the push rod help to seat the push rod in the divot of the push rod seats at one end and the hole in the rocker arm at the other end.

The pushrods are made of steel because it allows for them to with stand the forces constantly acting on them while the engine is functioning. Steel also lends to ease of manufacturing (see manufacturing for more). Steels properties are especially important to the push rods because of their slender shape. The pushrods need to function over the life of the engine without bending snapping or deforming under the extreme heats and forces of the engine. Steel is relatively, cheap, obtainable, and abundant and it meets the requirements of the system; therefore economics influences the choice of material the greatest.

The pushrods have very little in way of aesthetic properties. What can be obtained from the aesthetics of the pushrods clues to how they manufacturing (see manufacturing for more) and what material they are composed of, again the gray color implies something metallic in nature. The pushrods aesthetics only give clue to function, manufacturing, etc. and serve no other purpose as there are not visible while the engine is functioning.

Dimensions:

  • Length: 19 cm
  • Diameter: 0.5 cm

Weight: 0.5 lb (each)

Pushrods Manufacturing

To have the linear motion of the pushrod seats reach the rocker arms above the cylinders, pushrods are required to translate the force over that distance. Very simple in shape, the push rods are also deceptive. In actuality, they consist of 3 pieces, two spherical pieces and a central shaft.

The processes of manufacturing are likely as follows:

  • The two spherical end pieces look very similar to bearings with an added hole. This shape can likely imply that the process for manufacturing a bearing is used with an added step. Material would be stamped into a rough ball shape that would have any flashing removed then ground to reach a near to a sphere as possible. After this, the bearings would be drilled than affix to the central shaft by some form of welding. For attaching to the steel shaft, the spherical ends would be steel as well. The properties of steel allow for the spheres to be ground down to the correct precision and then drilled.
  • The central would be created by an extrusion process. Its shape has axial symmetry and constant cross-sectional shape. For the forces involved would have steel as the material of choice which would allow for the tub to be extruded.

Economic factors are the most important for the manufacturing process used. This particular part could have been lathed and the drilled. However, it was done in separate pieces with simple manufacturing processes, and then assembled.

Pushrods Complexity

Due to the simple function of a pushrod to merely translate a force from a push rod seats to a rocker arm, its function complexity is a 1.

The shape of a push rod offers axial symmetry as well as bilateral symmetry giving it a shape complexity of 1.

The manufacturing processes that go into creating a push rod give it a manufacturing complexity of 1.

Over all component complexity = 3

A pushrod takes the energy received from the pushrod seat and transfers it to a rocker arm. This gives it a component interaction complexity of 2.

Associated Dissection Step: 10

Rocker Arms

Figure [3]: Rocker Arms, Pushrods, and Seats

Part #: none Rocker Arms Function

The primary function of the rocker arms (see Figure 3) is to receive linear motion and by virtue of rotational motion, redirect the linear motion in another direction. The rocker arms receive linear motion from the push rods and pivot around a central axial point redirecting the linear motion in a downward direction toward the valves. The rocker arms are primarily associated with the transfer of mechanical energy by redirecting linear motion in a different direction than it is received by virtue of a pivoting rotational motion. The rocker arms function in closed lubricated environment that is under constant heat while the engine is functioning.

Rocker Arms Form

The best way to describe the shape of the rocker arms is that they are, from the side a boxy capital “T” that has depth as well making it three dimensional. The rocker arms “T” shape has a circular pivot at the junction where the top of the “T” and the trunk meet. The rocker arms have no notably symmetry as for their function does not require them to have any. It is important to note that there is a semi-circle hole in one side to the “T’s” top that acts as the resting point for the push rod to rest in, and as the point where the rocker arm receives it force. The pivot allows the rocker arms to act like see-saws but in reverse. The upward force of the push rod is transferred downward on to the valves. The pivot point, which is a bearing, redirects the force around that axis.

The rocker arms are made of steel. Like most other parts steel is chosen because it has the required properties to withstand the torsion and forces that the component, in this case the rocker arm, are subjected to. See manufacturing for more information on the how the material choice affects the manufacturing of the rocker arms and vice versa. Steel is relatively, cheap, obtainable, and abundant and it meets the requirements of the system; therefore economics influences the choice of material the greatest.

The aesthetic properties of the rocker arms only give insight to how the component was manufactured as well as the material the component is comprised of. The rocker arms are note visible when the engine is functioning. The grey color give indication that the part is probably comprised of something metallic. The surface finish gives clues into how the component is manufactured, for more information see the manufacturing section.

Dimensions:

  • Height: 5.5 cm
  • Width: 3.5 cm
  • Length: 7.5 cm

Weight: 2.5 lb (each)

Rocker Arms Manufacturing

These important parts reverse the linear motion, turning an upward motion into a downward motion. This change is for compressing and releasing the valves and the springs. The rocker arms themselves contain multiple pieces to achieve this.

The processes of manufacturing are likely as follows:

  • The head of the rocker arm is formed by casting and cutting (flashing removal), with a pair of holes drilled into it. Its nonsymmetrical shape does not lend itself to any manufacturing process other than casting. And the use of the holes in it (for bearings and an axle) would require the precision of a drilling process. The iron in the rocker head allows casting to be an effective manufacturing process.
  • The steel bearings inside of the rocker arm are cylindrical in shape. Due to this they were likely produced by extrusion to get the rough cylinder shape and then ground down to achieve the high precision. This grounding is evident in the smooth surface finish and is possible because of the bearings’ material.
  • The bearings rotate within a bearing raceway piece. This piece is likely made by stamping the material. Its thin width, malleable material, and simple geometry allows stamping to be done
  • The steel axle that rotates within the entire head of the rocker arm is a solid piece of metal that is extruded and ground. Its axial symmetry and constant cross-sectional shape would allow for the piece to be extruded while its very fine surface finish implies a grinding process was used. Being made from steel allows the axle to be ground down to the correct precision.
  • The entire rocker head then pivots around a base piece which then can be threaded into place. This part is cast and machined to the required tolerances. Its nonsymmetrical shape implies that it would be best to cast. Due to the high precision required on the hole through which the axle passes, drilling would be the process of choice. Some form of machining die would be one of the only ways to create the thread around the bottom protrusion. Like the rocker head, the iron in the base piece allow casting to be an effective manufacturing process.

The influential factors effecting the decision on the manufacturing processes would be economic factors. The choice of casting over completely machining the head would be to saving on cost and time in production.

Rocker Arms Complexity

Due to a rocker arm's simple function of switching the direction of a force, and by nature translating it some amount, its function complexity is a 1.

The shape of a rocker arm offers bilateral symmetry giving it a shape complexity of 2.

The manufacturing processes that go into making a rocker arm give it a manufacturing complexity of 3.

Over all component complexity = 6

A rocker arm will take the force of the push rod, and transfer it down into a valve and spring. However, to do this it must apply a force on the engine block. This gives a rocker arm a component interaction complexity of 2.

Associated Dissection Step: 10

Engine Block

Figure [4]: 2.2L Engine Block

Engine Block Function

The primary function of the engine block (see Figure 4) is to house all the connections and interactions of the rest of the engines components. The engine blocks primary function is merely a culmination of multitudes of tertiary functions. The engine block must with stand all of the forces, interactions, and flows from the rest of the components interacting with each other. The engine block is associated with both the flow of energy (mechanical and heat primarily) and the flow of materials (fuel, air, exhaust, etc.). The engine block itself is an environment that houses the rest of the engine components. The engine block’s environment is one of immense heat and stress due to the interactions of other engine components.

Engine Block Form

The engine block is essentially a rectangular prism. The rectangular shape provides multiple flat surfaces for the components and subsystems of the engine to attach to. In actuality the engine block has many intricacies, namely bountiful passage ways and holes throughout it to allow for coolant, oil, air, and fuel flow. The most recognizable of the holes are the four cylinders that hose the pistons, and where the combustion is performed. The engine block as a whole has no symmetry. Due to its need to volumetric spaces, the engine block is three dimensional. The engine block is the centerpiece of the engine and needs many different internal geometries to compensate for the subsystems for that is houses. The aforementioned cylinders are one example of an internal geometry that the engine block has, but there are others as well. The bottom of the engine bloc is primarily open to allow the crankshaft to rotate. There is a whole drilled in the side of the engine along its length that houses the camshaft.

The engine block is made of cast iron. Cast iron is chosen for two primary reasons. First, iron can be processed in to the intricate shapes required for the engine block (see manufacturing). Second, cast iron is durable, the engine block needs to be durable as for it has to withstand numerous and constant explosions within its center. It is important to note that in performance engines that engine blocks may be made of lighter materials, but high performance was not the intention of the this engine so cast iron was chosen because it is more affordable. Iron is relatively heavy, cheap, obtainable, durable, and abundant; therefore economics influence the choice of material the greatest.

The engine does have some aesthetic properties. The engine block is visible when the engine is assembled and function there for the outside of the block is painted black to dress up the engine a bit as well as prevent rust from forming on the outside of the block. The finish on the interior of the cylinder is extremely smooth; this is to eliminate as much friction as possible. One of the more interesting aesthetics of the engine block is the texture of certain finishes. This texture indicates that the engine block was manufactured using lost foam casting (for more information on this and how other aesthetic properties relate to manufacturing see the manufacturing section). The engine block as a whole has both functional and “beautifying” aesthetics.

Dimensions:

  • Length :44 cm
  • Height: 15 cm
  • Width: 24 cm

Weight: 100 lb

Engine Block Manufacturing

The components discussed all, in some direct or indirect way, interact with the engine block. This piece is central in the operation of the engine.

The processes of manufacturing are likely as follows:

  • The engine block is first and more or less entirely made from a lost foam casting processes. After the overall block is made, then removal based processes are applied. Sawing occurs to remove any extra iron that is still on the engine block from the casting process. Heavy drilling occurs to create future threads, mounting points and holes. Drilling with thread cutting bits takes place to form any needed screwing points. Milling occurs to carve out any cavities that simple drilling cannot create. Many sections of the engine are ground down to create smooth attaching points. The external texture of the engine indicates that a lost foam casting process was used to make it. At the front of the engine block, the top, and multiple other locations, feint circular lines are visible which are likely from a circular cutting tool, or less likely from a circular grinding process. The engine block is covered in threaded holes which would be made almost exclusively by drilling and thread cutting. The integral surfaces of the cylinders, as an example, exhibit a very fine surface finish which implies that grinding was used during the block’s creation. The use of iron as the material in the engine block makes casting a cost effective process that yields a strong component.

For the engine block's creation, again economic factors weigh the heaviest; however a crucial step adds other factors. The use of removal processes with iron as a material allow for easy reusing of the removed material which aids in keeping costs down. In addition to the economic concerns, the process of lost foam casting offers advantages over other casting processes, such as sand casting which can process dangerously large thermal waste in the form of high temperature sand.

Engine Block Complexity Due to the engine block's function of holding and directing all the components and forces, its function complexity is a 1.

The shape of the engine block, without a doubt, offers no symmetry which gives it a shape complexity of 3.

The manufacturing processes that go into creating the engine block give it a manufacturing complexity of 3.

Over all component complexity = 8

The engine block sees the greatest amount of component interaction. Many components are attached directly to the engine block and any energy or motion they have will be interacting with the block. This large amount of motion and energy, and transfer and conversion of them give the engine block a component interaction complexity of 3 (they would need to be broadened to adequately do the engine block justice).

Associated Dissection Step: N/A

Solid Modeled Assembly

The rocker arm, the pushrod seat, and the pushrod were modeled using Autodesk Inventor Professional 2011. This model displays how these three parts are assembled and connected in an overhead valve engine. One end of the rocker arm is raised by the camshaft, via the push rod and seat, and the other end acts as a valve stem, and opens either an intake or exhaust valve. This allows fuel and air to be drawn into the combustion chamber during the intake stroke, or exhaust to be expelled during the exhaust stroke. The leverage of the rocker arm is dependent on the ratio determined by the distance between the center of rotation of the rocker arm and the tip of the arm, divided by the distance from the center of rotation to the point acted on by the pushrod.

Figure [5]: Rocker Arm
Figure [6]: Pushrod Seat
Figure [7]: Pushrod
Figure [8]: Pushrod and Seat
Figure [9]: Full assembly: Pushrod, Seat, and Rocker Arm

Engineering Analysis

Problem Statement

Determine the amount of energy that is lost due to friction in one piston stroke.

Diagram

Figure [10]: Analysis of a Piston

F = Applied Force from Combustion

N = Normal Force from Cylinder Wall

ƒK = Kinetic Friction Force

V = Piston Velocity

Assumptions

  • Uniform Coefficient of Friction between the piston, piston rings and cylinder wall
  • Neglect Static Friction
  • Normal Force is the only force acting between the piston and the cylinder wall
  • Perfect Linear Motion of the piston
  • Constant motion of the piston

Equations

  • ƒK = µK N

Where, ƒK = Kinetic Friction, µK = Coefficient of Kinetic Friction, N = Normal Force

  • σ = ϵE = F/A

Where, σ = Stress, ϵ = ΔL/L , E = Young’s Modulus of Elasticity, F = Force and A = cW (L = Length, c = Circumference, W = Thickness of the Piston)

  • Representing the Force (F) from the Stress Equation as the Normal Force (N) from the Friction Equation: N = AϵE
  • Therefore: ƒK = µKAϵE = µKcWΔL/LE
  • Finally: Q = ƒKd = µKcWΔL/LEd

Where, d = Distance traveled in one stroke and Q = Energy Lost from Kinetic Friction in one piston stroke Estimated Values: Most important values that influence the energy lost from friction are estimated below. The other parameters are defined by general engine size and have small window for dimensional change.

  • µK = 0.11 for standard quality motor oil
  • E = 13.4*10^6 psi @ 21(˚C) for Gray Cast Iron


Discussion

Engineering Analysis was used to determine the amount of energy lost due to friction in one piston stroke. This would be an important factor to consider in the design process. Friction is a force that typically converts usable energy into waste heat. By calculating the energy lost due to friction, an engineer may be able to design a more efficient engine. Also, this energy lost would have to be accounted for by adjusting the energy input of the system so it behaves as designed.

By understanding forces like friction that take energy out of the system, engineers can change certain parameters that influence its outcome; this creates a more energy efficient system. The most influential parameters that affect friction are the Coefficient of Kinetic Friction and Young’s Modulus of Elasticity. Some examples of typical values where given in the equation section; these parameters are then adjusted by choosing the appropriate motor lubricants and product material to get the desired value. This will then decrease the friction force as much as economically possible. The other dimensional changes would have to be calculated based on the general size of the engine and other factors. This would help create a more efficient system.

The assumptions stated above have a significant impact on the way this problem was modeled. There are other forces acting on the piston and there is most likely a more accurate ways of solving this problem; but this an estimated model to understand the dynamics of the system from an engineering analysis prospective. The engineering analysis process is a powerful tool used during the design process.

Design Revisions: Components/Sub-systems

Figure [11]: Overhead cam system

An engine meant for mass production in the global economy must meet ever increasing standards of performance, efficiency, and reliability. As gasoline becomes more costly, and environmental regulations more stringent, the demand for engines which maximize fuel economy grows proportionally. In order to remain competitive, an engine must balance efficiency and output with overall economy; in other words, performance must be balanced with price. There are several design variations that might be implemented in this engine which will result in significantly better performance without substantially affecting its overall economy.


Significant improvements in both fuel economy and power output can be realized by replacing the current pushrod valve timing system with an overhead cam system, as modeled in Figure 11, which is capable of varying the duration of valve opening with engine speed. The current system, while advantageous in its design simplicity, has a negative impact on fuel economy when compared to an overhead cam setup with variable valve timing (VVT). The pushrod setup must be designed to optimize valve timing at only one engine speed, thus sacrificing both performance and efficiency at all other speeds. By replacing this system with an overhead cam and VVT, not only is the engine able to run optimally at various speed; the need for pushrods is eliminated as well, thereby reducing mechanical drag on the engine.

Figure [12]: Direct injection system

The currently used throttle-body fuel injection system is outdated technology which served primarily to transition from carburation to fuel injection without significant design revisions. This system operates by injecting fuel into the cylinder at a single point, the start of the compression cycle, and is unable to be tailored to whatever demand the engine may be subjected to. In comparison, a direct injection system (see Figure 12) may inject fuel at any point in the compression cycle, enabling extremely efficient operation at idle or constant speed by injecting fuel near the end of the compression cycle.

As seen in the engineering analysis, the piston rings have a great impact on power lost to friction in the operation of the engine. In light of this, it is clear that improvements in efficiency may be made by altering the piston rings so as to minimize the friction between them and the cylinder. While higher performance materials such as chromium and molybdenum, and ceramic coatings on both the piston rings and cylinder sleeves present a large price increase relative to cheaper, gray cast iron parts, the additional cost with respect to the total cost of a vehicle is slight, and may thus be absorbed by the consumer.

Gate Four

For Gate 4, Group 12 was tasked with reassembling the GM 4 cylinder engine assigned to them, and documenting the step by step process in a meaningful manner. Along with the reassemble, Group 12 had to develop three design revisions for the engine, on a system level. This Gate allowed the Group to round out their analysis of the engine and make detailed observations based on their experience.

Coordination Review

Work Assessment
There were no conflicts or problems within Gate 4 as far as actual work on the engine. All work in the lab was done on time as well as effectively. This success was half due to a well established work proposal, and Group members' willingness to do the work and do it well. The reassembly performed in the Gate required some expertise in order to complete (i.e. how to put the pistons back in the block). Because of similar problems faced in Gate 2, Group 12 anticipated these difficulties and came prepared. Group manager Marc Krug brought in a ring compressor to put the pistons back in the block, and together the group researched how to put the harmonic balancer back on. Thanks to the preemptive planning the engine was reassembled in less than half the time it took for disassembly. Seeing as the work on the engine is completed, there are no foreseeable future problems from a working standpoint.

Management Assessment
There were no problems within Gate 4 from a management standpoint. All sections of the Gate were submitted and completed on time. Due to problems with previous Gates, Group 12 has already adapted properly to complete Gate 4 efficiently (see previous Gates for those problems). Another reason Gate 4 was rather seamless was due to its similarities to Gate 2. Group 12 already had an extremely good idea of what was expected for the Gate submission, so completing the requirements of the Gate was rather simple. Group 12 has already gone ahead and established what needs to be done for the completion of the project and there are no foreseeable problems that may arise. Because it is getting late in the project, Group 12 has multiple resources (witnessing other group presentations, past Gate grading sheets, etc.) to draw from to know very precisely what needs to be done to draw the project to a close.

Product Reassembly

Table 4, below, is a step by step reassembly of the GM 4 cylinder engine assigned to Groups 12 and 14. The reassembly was performed and documented as a collaborative effort with Group 14. During the dissection process members from both groups were always present to ensure both groups gained as much valuable experience with the engine as possible.

Table 4 includes the components/parts of the engine, the order the components/parts were reassembled in, the tools needed replace each component/part, and a picture of the component/part, and the relative location if where each component/part goes on the engine. It is important to note that the engine was reassembled while on an engine rotisserie, and unless stated within the step, the engine was right side up. It is also important to acknowledge that all threads on the engine required counterclockwise motion to loosen them and clockwise motion to tighten them.

Location
Table 4 includes a description of where to place the part correctly, as well as a relative location of that place on the engine. Below, Figure B, Figure C, Figure D, and Figure E give three different angles at which to reference the engine (the back of the engine is the side opposite the one show in Figure C). The figures allow one to have a better understanding of the arrangement subsystems on the engine making it easier to reference where the parts need to go on the engine. The descriptions if the locations on the engine (left [13], front[14], right[16], etc.) are relative to how the engine was mounted on the rotisserie provided for this project. It is important note that similar locations may be give for some parts (especially for the sensors). Despite the similarities in the description if the location, when the actual reassembly takes and the engine is front of the person performing the task it is clear where parts go (holes line up correctly, each only fits properly in its correct spot, etc.).

Figure [13]: Left Side View
Figure [14]: Front View
FIgure [15]: Overhead View
Figure [16]: Right Side View

Difficulty

Ease of Assembly

With the difficulty of a task varying from one individual to another, creating a scale for gauging it can be troublesome. The rating system for this gate will split up and consider two sides of a particular task, the tangible/physical requirements and the mental/knowledge requirements. If assembling or removing a component takes large amounts of force, it will be physically difficult. If a task requires special knowledge, it will be mentally difficult. This difficulty also will consider time for each task. Some tasks may consume large amounts of time and indicate a difficult step, though it should be said that some steps are simply many easy tasks and are not difficult despite the time taken.

In this engine assembly, the scale of difficulty will begin with the removal of a simple bolt. This level of difficulty will be rated as a 1. A 1 level difficult will be a process that takes very little time to finish, requires little physical and mental effort, and can be accomplished with basic tools (socket wrench, screw driver, even hands).

A level of 2 will imply a medium degree of difficulty. This is a task that consumes more time than an easy process, required more effort/force than an easy task, or needed more mental attention than an easy task. While a 2 shows the removal of something that acted as an obstacle, that step did not cause serious interruption of the assembly.

A level 3 is a rating of hard and is the highest level of difficulty. Something of this level requires a special tool, a very large amount of force, a great deal of time, and/or some thought.



Table 4: Step by Step Reassembly
Step # Part Location Procedure Tools Used Difficulty Image
1 Camshaft round hole, bottom left side of the front of the block Slide the camshaft into the corresponding hole in the engine. hands 1 Camshaftg14.jpg
2 Distributor Timing Gear round hole, back of the left side of the block Slide the gear into the corresponding hole in the engine block. Replace the 10 mm bolt. 10 mm socket, 1/4 in drive ratchet 1 Distributortiminggearg14.jpg
3 Oil Pressure Sensor round hole next to small threaded hole, middle of the left side of the block Place the sensor in the corresponding block on the engine block. Replace the 8 mm bolt. 8 mm socket, 1/4 in drive ratchet 1 Oiltemperaturesensorg14.jpg
4 Temperature Sensor round threaded hole, back of the left side of the block Screw the temperature sensor into the corresponding threaded hole on the block. 22 mm open end wrench 1 Temperaturesensorg14.jpg
5 RPM Sensor round hole next to small threaded hole, middle of the left side of the block Place the sensor in the corresponding block on the engine block. Replace the 8 mm bolt. 8 mm socket, 1/4 in drive ratchet 1 RPMsensorg14.jpg
6 Pistons Four cylinder, center of the engine block Making sure the divots on the ring compressor are on the bottom (furthest from top of piston) tighten the compressor around the rings. Slide the piston into the top of the cylinder allowing the ring compressor to rest on the rim of the cylinder. Using the wooden handle of a rubber mallet, lightly tap the piston down into the cylinder (make sure the ring compressor does not slide into the cylinder). ring compressor, rubber mallet 3 Pistonclampsg14.jpg
7 Crankshaft U-shaped braces, bottom of the engine block Lower the crankshaft into place (the gear toward the front of the engine). Make sure that the crankshaft rests in each connecting rod of the pistons. It is suggested that engine be upside down for this step. hands 1 Crankshaftg14.jpg
8 Piston Clamps on top of the crankshaft (when engine is upside down), bottom of the engine block Slide the clamps on to the bolts on the piston connecting rod. Replace the nuts on each bolt (8 total). It is suggested that the engine be upside down for this step. vice grips 1 Pistonclampsg14.jpg
9 Back Crankshaft Clamp on top of the crankshaft (when engine is upside down), bottom back of the engine block Line the clamp up with the corresponding holes on the block. Replace the one 15 mm bolt. ). It is suggested the engine be upside down for this step. 15 mm socket, 1/2 in drive ratchet 1 Backcrankshaft clamp.jpg
10 Crankshaft Clamps on top of the crankshaft (when engine is upside down), bottom of the block Place the clamps in the corresponding spots on the engine block in the correct order. (The order goes Blue, Green, Orange, and Pink from the back of the crankshaft to the front).

Replace the two 15 mm bolts for each clamp (eight bolts total). It is suggested the engine be upside down for this step.

15 mm socket, 1/2 in drive ratchet, rubber mallet 1 Crankshaftclampsg14.jpg
11 Oil Pump on top of the back crankshaft clamp (when engine is upside down), bottom of the engine Slide the shaft of the pump into the corresponding hole on the engine block being sure the holes of the pump line up with the holes on the back crankshaft clamp. Replace the two 15 mm mounting bolts. ). It is suggested the engine be upside down for this step. 15 mm socket, 1/2 in drive ratchet 1 Oilpumg14.jpg
12 Pushrod Seats Eight holes in a line, top left hand side of the engine block Slide the push rod seats into the corresponding holes in the block. hands 1 Pushrodseatsg14.jpg
13 Chain Tensioner, Timing Gear, Timing Chain Timing Gear: in from of the camshaft, front of the block

Timing Chain: around the timing gear and crankshaft gear, front of the block

Chain Tensioner: between the timing gear and the crankshaft gear, behind the timing chain

NOTE: An extra pair of hands is very helpful for this step, so it is suggested that at least two people perform this step.

Slide the timing chain on the gear on the end of the crankshaft. Slide the timing gear into the other end of the chain making sure that it is rotated properly and the keyway on the gear lines up. Slide the timing gear onto the block to make sure everything lines up. Begin to slide the timing gear back of making sure the timing chain does not fall off either gear. Holding the timing gear away from the block, maneuver the chain tensioner behind the chain and between the two gears. Once everything is in place, replace the 15/16” bolt in the center of the timing gear. Replace the 11 mm bolt and washer into the chain tensioner as well at the T-40 Torx screw.

Chain Tensioner: 11 mm socket, 1/4 drive ratchet, T-40 Torx screwdriver

Timing Gear: 15/16 in open end wrench

Timing Chain: hands

Chain Tensionr: 2

Timing Gear: 2

Timing Chain: 2

Timingchainasemblyg14.JPGChaintensionerg14.jpg
14 Timing Chain Cover on front of the timing chain and timing gear, front of the engine block Line up the timing cover with the holes on the engine block. Replace the six 8 mm bolts to hold it in place. 8 mm socket, 1/4 in drive ratchet 2 Timinggearcoverg14.jpg
15 Harmonic Balancer on the end if the crankshaft, front of the engine block Place harmonic balancer in the corresponding spot on the engine block making sure the key way lines up properly. Using a rubber mallet knock the harmonic balancer back in to its hole.

NOTE: the harmonic balancer may not go on all the way with a rubber mallet. When the center bolt on the belt wheel is tightened all the way the harmonic balancer will get pulled the rest of the way in.

Rubber mallet 3 Harmonicbalancerg14.jpg
16 Belt Wheel on the harmonic balancer, front of the engine block Line up the holes on the belt wheel with those on the harmonic balancer. Replace the three outer 13 mm bolt and the one central 18 mm bolt. 18 mm & 13 mm sockets, 3/8 & 1/2 drive ratchets 1 Beltwheelg14.jpg
17 Oil Pan covering the crankshaft, bottom of the engine block Line up the corresponding holes on the oil pan with those on the block. Replace the twelve 10 mm bolts. It is advised that the engine be upside down for this step. 10 mm socket, 1/4 in drive ratchet 1 Oilpang14.jpg
18 Oil Filter on the threaded mount, left side of the engine block toward the front Screw on the oil filter to the corresponding threaded mount. hands 1 Oil filterg14.jpg
19 Camshaft Pulley left of the camshaft/timing gear, left side of the front of the block Placing the pulley in the correct spot on the engine, replace the 15 mm bolt. 15 mm socket, 1/2 in drive ratchet 1 Camshaftpullyg14.jpg
20 Water Pump Pulley on the protrusion, front of the block on the right side Line up holes on the pulley. Replace the two 16 mm mounting bolt. 16 mm socket, 1/2 in drive ratchet 1 Waterpumppullyg14.jpg
21 Oil Temperature Sensor round threaded hole, left side of the block in the middle Screw in the sensor to the corresponding threaded hole in the engine block. hands 1 Oilpressuresensorg14.jpg
22 Silver Coolant Thermostat hole inside flat oval shape on back of protrusion, right side of the engine block toward the front Line up the housing with the corresponding hole on the engine block. Replace the two 13 mm bolts. 13 mm socket, 3/8 in drive ratchet 1 Silvercoolantthermostathousingg14.jpg
23 Spring Gasket in the end of the silver coolant thermostat housing, right side of the engine block toward the front Place the spring gasket in the end of the silver coolant thermostat housing. hands 1 Springgasketforcoolantg14.jpg
24 Black Mount for Coolant Thermostat in front of the spring gasket on the end of the silver coolant thermostat housing, right side of the engine block toward the front Line up the mount with the end of the silver coolant thermostat housing and replace the two 8 mm bolts. 8 mm socket, 1/4 in drive ratchet 1 Blackmountforcollantthermostatg14.jpg
25 Pushrod Guides on top of the pushrod seats, top left side of engine block Place the guides in their proper spot in the block.

NOTE: The guides only fit properly in one direction so test both to make sure they are being placed properly.

10 mm socket, 1/4 in drive ratchet 1
26 Valve Housing on top of engine block Place the valve housing (valve springs up) on the engine block making sure everything lines up correctly. Replace the five 15 mm internal bolts and the five 15 mm external bolts. 15 mm socket, 1/2 in drive ratchet 1 Vlave houseingg14.jpg
27 Pushrods holes next to valve springs, inside valve housing Slide the pushrod into the holes in the bottom of the valve housing next to each valve spring. Make sure the pushrods seat correctly in the push rod seats. hands 1 Rockerarmsg14.jpg
28 Rocker Arms threaded holes on mounts between pushrods and valve springs, inside valve housing Screw each rocker arm into the thread holes in between the valve springs and the pushrods. Line up the divot end of the rocker arm with the top of the push rod and the other end with the center of the valve spring. Be sure that the rocker arm is making contact with both the pushrod and the valve spring. 10 mm socket, 1/4 in drive ratchet 1 Rockerarmsg14.jpg
29 Valve Cover on top of the valve housing Place the cover on top of the valve housing being sure the holes line up. Replace the six 10 mm bolts. 10 mm socket, 1/4 in drive ratchet 1 ValveCover.png
30 Exhaust Manifold (and O2 Sensor) four round holes in a row, left side of the valve housing (two holes toward back) Line up holes on the manifold with the corresponding holes on the valve housing. Replace the four 13 mm bolts. 13 mm socket, 3/8 in drive ratchet 1 Exhaust manifoldg14.jpg
31 Mounting Bracket in front of the valve housing, curved section to the bottom left, front of engine Line up the bracket with the corresponding holes on the block and replace the four 13 mm mounting bolts. 13 mm socket, 3/8 in drive ratchet 1 Mounting bracketg14.jpg
32 Belt Tensioner Pulley threaded hole, center bottom of mounting bracket, front of engine Screw the 13 mm center bolt of the pulley into the corresponding hole on the mounting bracket. 13 mm socket, 3/8 in drive ratchet 1 Belttensionerpullyg14.jpg
33 Distributor Mounting Bracket and Spacer back of valve housing Place the spacer between the valve housing and the bracket. Replace the five 8 mm bolts. 8 mm socket, 1/4 in drive ratchet 1 Distributor mounting bracketg14.jpg
34 Distributor on distributor mounting bracket, back of valve housing Line up the holes on the distributor with the corresponding holes on the distributor’s mounting bracket. Replace the three 13 mm mounting bolts 13 mm socket, 3/8 in drive ratchet 1 Distributorg14.jpg
35 Intake Assembly left side of valve housing Line up the corresponding holes on the assembly with the rest of the engine. Replace the three 13 mm standoff bolts, two 13 mm mounting bolts, and two 13 mm hex nuts. 13 mm socket, 3/8 in drive ratchet 1 Intake assemblyg14.jpg
36 Fuel Rail above intake assembly, left side of engine on top Screw in the two 10 mm mounting bolts. 10 mm socket, 1/4 in drive ratchet 1 Fulerailassemblyg14.jpg
37 Spark Plugs three threaded hole in a row, right side of the valve housing Screw in each spark plug to the corresponding hole on the block. 10 mm socket, 1/4 in drive ratchet 1 Sparkplugsandwires.jpg
38 Spark Plug Wires Ends of spark plugs to the plugs on the distributor, run from right side of valve housing to the back of the valve housing/distributor Plug the 90 degree ends of the wires on to the corresponding numbered sots on the distributor and the on the ends of the wires to the corresponding spark plug. hands 1 Sparkplugsandwires.jpg
39 Coolant Tube Hole in the front of the valve housing, runs from hole along the right side of the valve housing Slide the coolant tube on to the threaded studs on the engine. Screw on one 13 mm hex nut and one 15 mm hex nut. 13 mm & 15 mm sockets, 3/8 in drive ratchet 1 Coolant tube.jpg
40 Dipstick Tube Round hole, bottom right side of engine block toward the back, tube runs up the right side of the engine Slide the bottom of the dipstick tube into the corresponding hole on the engine and replace the 16 mm mounting bolt. 16 mm socket, 1/2 in drive ratchet 1 Dipstick tubeg14.jpg
41 Vacuum Sensor center if the left side of the block Place the sensor on the block and replace the 16 mm bolt. 16 mm socket, 1/2 in drive ratchet 1 Vacuum sensor14.jpg

Original Assembly
Group 12’s objective while reassembling the engine was merely to complete the task correctly, as opposed to the original assembly of the engine which would have much more precise process. The original assembly of the 2.2 liter GM 4 cylinder engine would have been a process developed for efficiency and productivity. The assembly would have been done in a factory, and it would have been completed through a series of stations in an assembly line. While the manufacturing of most parts on the engine could have been automated, it is much more likely that the actual assembly of the engine was done by people. The engine would start as simply as the engine block and then go through a series of stations, each which would as specified systems to the engine. Each station would be equipped with a technician trained for that specific part of the engine assembly, as well as the correct tools to complete the job. Electric or impact drivers would be used to install the fasteners on the engine, and each driver would be calibrated so that the fasteners it is meant to install are torqued properly. The purpose of the original assembly of the engine would have been to efficiently assemble a working engine that was assembled to certain standards of safety and performance.

Disassembly-Assembly
Assembling the GM 4 cylinder engine can be represented much as a “mirror” of the disassembly. For most of the components in the engine, the same tools were used for assembly and disassembly. The tools were now just applied in the opposite manor than the disassembly (tightening as opposed to loosening). Where the same tools weren’t used it can be generalized that the process used to reassemble the component was the “mirror” or the “opposite” of the disassembly step. For example, the harmonic balancer was pulled out with a gear puller in the disassembly, and for the reassembly the opposite was applied, it was pushed in with a rubber mallet. Even the pistons, which are probably the most difficult component to replace, followed a “mirror” process. For disassembly the pistons were pushed from the bottom of the cylinder out the top, and for reassembly the pistons were pushed from the top of the cylinder down into the cylinder (the only difference in the step is having to reapply compression to the rings). The steps of the assembly process can even be reversed to get a similar order of disassembly steps.

Design Revisions: System Level

Figure B: Sign at GM Powertrain; Tonawanda, NY
It is important to not disrupt manufacturing at existing facilities, as this will have a negative impact on the local community, and possibly affect sales/production costs.


In recommending component and subsystem level revisions, changes to additional subsystems must be anticipated and accounted for. Often, a change intended to affect a particular subsystem becomes a system-wide revision. Therefore, any and all design revisions must be reviewed carefully at the system level, in the light of economic, environmental, global, and societal concerns. Following is such a review for the design recommendations above:

Changes to the valve-timing setup, i.e. switching to an overhead cam engine, will involve many ancillary revisions, necessitated primarily by the change in the physical location of the camshaft in the engine, and the elimination of the pushrods. Moving the cam out of the block and removing the pushrods will require changes to the engine block; and placing the cam in the valve housing will require changes to the housing to accommodate the cam, as well as changing the location of the timing gear. These changes will have a large initial expense, in both design and manufacture.

Direct-injection is a more complicated process than any of its predecessors, as it involves spraying fuel directly into the cylinders, as opposed to into the valve housing. Changes will need to be made to the engine block to accommodate the injectors, and the entire intake and throttle assembly will need to be redesigned. Additionally, the engine management program will need to be changed to accommodate the additional injector timing control required.

If the material properties of the pistons are altered, e.g. by lightening or reducing friction drag, the entire flow of mechanical energy through the engine can be expected to be disrupted. Changes may need to be made to engine balancing, for example.

As all of the recommended changes will necessitate changes in overall engine structure, each can be expected to represent a significant initial cost hurdle. Any initial expense, however, can be expected to represent a greater rate of return in increased sales, as well as in government incentives. Additional considerations include manufacturing capabilities at various localities—from a societal standpoint it is very important that manufacturing not be disrupted at existing plants. From a global standpoint, it is important that the engine not lose its ability to be used in a variety of geographic localities and urban environments. As these changes should increase the engine’s versatility—particularly by increasing the optimal power band—this should not be an issue.

Figure [17]: OHV Head
Figure [18]:OHC Head

References

Development Profile
Anderson, Doug. "Rebuilding the Chevy 2.2L Engine: Engine Builder." Engine Builder - Serving Professional Engine Builders and Rebuilders with Information on Rebuilt Engines, Engine Parts and Performance Engines. 1 July 2000. Web. 21 Sept. 2010. <http://www.enginebuildermag.com/Article/2437/rebuilding_the_chevy_22l_engine.aspx>.


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