Revision as of 04:00, 14 December 2009

Executive Summary

Group 9 received a 2.2 liter 4 cylinder gm engine for their reverse engineering project. The engine was not operational when received but otherwise in good condition. This project was completed in cooperation with group 24. The engine was divided amongst the two groups with group 9 being responsable for the belt drive system, camshaft and crankshaft. Wheras group 24 was responsable for the headers and pistons. The project was to be completed over the course of a semester and was broken down into 5 stages or gates.

Gate 1 is the request for proposal. In this a work proposal is laid out. The work proposal discusses the overview of the work plan, the tools and time required, and the group's capabilities and shortcomings. Gate 1 also lays out a management proposal. The management proposal goves an overview of the management plans. This lays out responsabilities of each member and the role they will play. This also assigns each person a leadership role based on their expertise. Meeting times are also planned out as well as a plan to resolve conflicts. Gate 1 also dealt with the intitial product assessment. This is where the product is a report answering several questions about the product based on an initial assessment.

Gate 2 is the preliminary project review. This is where the product is disected and documented with images illustrating how the engine was taken apart. A difficulty is assigned to each task as well as details where difficulties occur. A cause for corrective action will also be submitted here detailing further how problems were resolved and how well the previously discussed plans played out.

Gate 3 is the coordination review. Here each part is analyzed in detail post disassembly. Each part is analyzed in terms of function, shape, material, manufacturing process, and the forces acting on it. Upon analyzing the parts design revions are proposed to improve the product. To increase the thoroughness of the review certain parts were solid modeled while others were analyzend with engineering analysis.

Gate 4 is the critical project review. This is where the product was reassembled while keeping the same level of detail as when the product was disected. At this point the product was reevaluated compared to before the disassembly.

Gate 5 is the delivery. This includes finishing the wiki accompanied by a compliance matrix ensuring the completion of all parts. This stage also encompasses an oral presentation of the results of the project.

The project was successfull in achieving the outlined objectives (as outlined in the introduction). The product was dissasembled and reassembled successfully while being analyzed along the way. Below is the results of the project.

Introduction

The main objective of this project was to disect and analyze an assigned product. Group 9 was given a 2.2 liter 4 cylinder gm engine. The engine was in non functioning condition. Understanding how products work and how to apply engineering logic to real world products is a very important skill to develop for up and coming engineers. This project reinforces these key skills as well as aims to improve group working skills and help create better decision making skills. This will also give a chance to showcase technical writing skills devolped in class.

Gate 1: Request For Proposal

Work Proposal

Approach for Disassembly

The product assigned to Group 9 is a 2.2 Liter GM inline 4 cylinder engine. Group 9 plans on collaborating with group 24 who have the same engine to work on. The planned components for dissection are the belt drive system,camshaft and crankshaft. Group 24 has revealed they will work on the headers and pistons. As a group, step by step photographic documentation will be taken throughout the disassembly/reassembly processes. In addition to the documentation, clear labeling of all the components will ensure a smooth reassembly process. The engine components are to be dissected using a combination metric wrench set, pliers and Allen wrenches. English/customary units will be be necessary because automobile engines are made to internationally compatible therefore the fasteners are in metric. Estimated time for dissection is approximately 3 to 4 hours spread over 2 weeks. Along the way of the project, group 9 expects to do some outside research because overall the group is not experienced with engines. Four of the five members of group 9 do not have previous knowledge of the function of engine components, where components are located, and how to disassemble/reassemble. Another challenge will be working and coordinating efforts and schedules with group 24. Group 24 must disassemble their components before group 9 can begin the disassemblly process. Space in the lab will also be a challenge, as the engine is fairly compact and workspace is limited. Reassembly will be challenging due to the complexity of the components.

Capabilities and Shortcomings

As a whole each member of group 9 has certain strengths to contribute. Bryan is the only person on our team with knowledge and experience with engines, the components that are part of the engine and disassembling/reassembling. Richard is experienced in 3D modeling with CAD and Pro Engineer. Michael has HTML knowledge and is quick at learning coding and related skills. Christine has experience as being leader of a group. Adi is always available and quick to respond and initiate conversation via e-mail and telephone. Despite the strengths group 9 still has shortcomings. All members in Group 9 except for Bryan have no prior knowledge of how engines work. As a group it is imperative to further develop knowledge of the internal combustion engine, dissection and assembly processes. Along with research of the internal combustion engine it is also important to know how all the parts function, if the engine was intact and working. Regardless of this shortcoming group 9 has a strong interest in the subject and view the assignment as a challenge. Ideally the interest in the subject will stimulate progress.

Management Proposal

Group Roles

The group will work on the project together so that all members will have a chance to edit the wiki, solid model, disassemble, etc. The purpose of the roles is simply to make certain people accountable for certain part of the project. Roles are expected to overlap once the project is underway, but accountability will remain as agreed upon by the group. As stated in the work proposal, the members in group 9 are expected to help one another with each part of the project. Team work is a major part in successfully meeting the challenge posed. Working together will result in an efficient outcome. Group 9 are efficient individuals but have not worked with one-another previously. To resolve this conflict each member is responsible for certain aspects of the project but will also be available for extra help and questions when another member is unsure of something. The biggest conflict group 9 will face is meeting regularly with all members present due to the differences in schedules and living arrangements. All members except Bryan live on campus so meetings will be held on campus. Group 9 has decided to meet every Wednesday at 5:00 p.m. to ensure the conflict is resolved.

"Project Manager" - Christine Menton

• In charge of keeping the group on task and makes sure that everyone adheres to the plan (proposal, gannt chart, etc)
• Leads general meetings and breaks up tasks among the group so the schedule is maintained.
• Makes sure group work is presentable and formatted well (final editor).
• Leads the group in gates 1 and 5.

"3D Modeling and Tech Expert" - Richard Lipcyznski

• Leads the team in the 3D modeling of the parts.
• In charge of the component listing/summary.
• Leads the group in analyzing the product and formulating design revisions.
• Leads the group in gate 3.

"Dissection Leader" - Bryan Papaj

• Leads the group in dissection and reassembly.
• Makes sure group gets to the lab and that everyone stays informed as to what were doing.
• Makes sure parts are labeled or easily identified so reassembly will be easier.
• Takes pictures of all the parts.
• Leads the group in doing Gates 2 and 4.

"Wiki Leader" - Michael Huffman

• In charge of learning about how to edit wiki, embed pictures, format, etc.
• Instructs the group how to properly use wiki.
• First editor of the content published on wiki page.
• Makes sure wiki is constantly updated with group progress.

"Communication Liaison" - Adityavikram Rajawat

• Contact point between our group and the professor/teaching assistants.
• Takes notes at group meetings and sends information through e-mail.
• Keeps group connected on days when members are missing from meetings.
• Takes over as Project Manager in Christine's absence.
• Ambassador to other groups, specifically group 24.
• Ensures group 24 removes their components so group 9 can begin disassembly.

Meeting Info

As stated in the group roles, group 9 plans to meet at least once a week on Wednesdays at 5:00 p.m. Group 9 We will meet in the classroom and go over to the library in Capen or computer lab in Bell Hall. This meeting will be to review group progress and assess current standings. Tasks for the upcoming week will be divided up amongst the group by the Project Manager (Christine), or in her absence the Communication Liaison (Adityavikram). Notes for the general meeting will be taken by Adityavikram and sent out to everyone by e-mail so there is no confusion as to what everyone is doing. The general meetings will be supplemented by additional meetings when needed. Group 9 plans to begin dissection starting on Monday October 12, 2009. Lab and dissection progress will be cataloged during these meetings.

Work will be managed directly using a Gannt chart which tracks progress and deadlines. Completed tasks are in blue.

Figure 1: Updated Gannt chart showing the planned deadlines and work periods throughout the project.

Initial Product Assessment

Intended Use of the Product

GM engine

The intended use of this product is to take air and fuel in and turn it into work. The work will then be transmitted through the transmission to the axles in order to drive the wheels of a car.

Is the product for home or professional use?

This product is intended for both home and professional use. The GM 2.2 L engine is made specifically for use in an automobile. Automobile engines are used by home owners and professionals alike. Homeowners maintain their engines to a certain degree(oil changes, air filter). Professionals are more knowledgeable of engine maintenance and can diagnose and fix larger problems with engines.

What are the different functions of the product?

The main function of this product is to produce mechanical work. This is its only function.

How the Product Works

How do you think the product works?

The engine takes electrical energy, air, and fuel in. It then compresses the fuel and air mixture, ignites it, which makes it combust into thermal energy, which does work on the pistons crankshaft. This work done on the crankshaft is relayed to work out of the system.

What types of energies are used?

The engine uses electrical, chemical, thermal, and mechanical energy in it's function.

How are these types of energies transformed and modified?

The process starts with electrical energy in the spark plugs. Air and fuel inside the cylinders is compressed and ignited which creates thermal energy. The extreme pressure inside the cylinder forces the pistons down which turns the crankshaft. The energy is now mechanical which can be used to power the drive shaft. Due to the internal combustion for the small amount of fuel intake, there is a much greater output in terms of mechanical work.

Product's Functionality

Is the product currently functioning?

The product is not currently functioning. An engine requires many other outside parts to operate. This system of parts will not available to us throughout the project.

If there are any problems, what do you think they are coming from?

Since we do not have all of the parts necessary to even start the engine it is clearly seen that it would not function anyway. The engine block itself has a large hole cut out of the side of the piston wall. If the pistons are not allowed to compress the gas/air mixture the combustion would not occur. There are also many other parts cut open into cross sections such as the oil filter. Since those parts do not form a closed system the engine would have too many problems and therefore fail to operate.

Product Complexity

How complex is the product?

Defined by the Merriam-Webster Dictionary complex is a whole made up of complicated or interrelated parts. Based on this definition the GM 2.2 L 4 cylinder inline engine is complex. It is complex because of the multiple number of interrelated components, advanced systems and complicated processes. Group 9 estimates that there are at least 5 different systems within the engine and roughly 100 individual components including fasteners.

For the individual components how complex are they?

The individual components are are not very complex by themselves. Most of the components are just metal or plastic pieces joined together in an elaborate way to create the complex system that is the engine. The form of the engine is determined by the function it creates.

Materials Used in the Product

What materials are clearly visible?

This product is primarily composed of various metals. It is mostly made of steel, hardened plastics and aluminum. Steel is easily recognizable because it has a rough finish, poor shine and is very heavy. Hardened plastics have a dull finish and rather light but durable. Aluminum has a shiny and smooth finish, is relatively light but at the same time strong. Rubber and copper are used in the wires for insulating and conducting properties respectively.

What materials do you think are not visible but present?

Group 9 can assumes the above materials of steel, aluminum, plastic and rubber are present but not visible. Some examples based on previous knowledge are :

• Engine block is steel
• Pistons are aluminum
• Pulleys are hardened plastics
• Gaskets are rubber for sealing purposes

Product Satisfaction

If you had to use this product, would you be happy with it?

It is unsure to say if group 9 would be happy to use the GM 2.2 L engine. Since the engine does not function there is no way of knowing if the engine is efficient, quiet or noisy, and also substantial if placed in an automobile. If the engine was working properly, group 9 would be happy with it because it is a rather well designed engine for mass produced automobiles.

Is the product comfortable to use?

The product is comfortable to use in a car. Standalone, this product is rendered useless. Cars are a very comfortable mode of transportation (especially compared to walking) and the engine just supplies work to it. The engine in no way makes the trip uncomfortable. It can however be inconvenient when it doesn't work.

Is the product easy to use?

This product is easy to use in a car, but again on it's own this product is rendered useless. Starting a car is very simple, you just turn a key. Using an engine is a very easy way to power a car and makes long distance transportation far more easy and convenient.

Does the product require regular maintenance? If so is the product easy to service?

This product does require regular maintenance, which is serviced by professionals. This makes servicing the engine fairly easy to the owner of the vehicle but it can be costly and time consuming.

Alternatives to the Product

What other alternatives to your product are there? How do these alternatives compare?

Our engine is quite standard but there are countless numbers of other engines out there. There are many alternatives, including different sizes, different fuel types, and different cylinder sizes. The larger engines will give more performance, but less fuel efficiency compared to our engine. Different fuel type engines include hybrid, electric, bio-diesel, and diesel.

What are the differences in cost?

Other fuel type engines such as a hybrid are usually more in cost compared to a gasoline engine. However, the hybrid engine will save more money over a longer period of time because their needed fuel is much less. Engines with more cylinders produce more power, and also have more fuel intake. Again, with more power comes more cost.

What are the advantages?

There are different performances for different cylinders. Our engine is a 2.2 liter inline 4 cylinder but there are 1.6L, 2.4L, etc., all with 4 cylinders. Advantages of a larger engine or better performing engine are increase in output in the form of speed/torque. The 2.2L is a good blend of performance, efficiency and cost.

What are the disadvantages?

The disadvantage of a more powerful engine is less fuel efficiency and for a hybrid/electric the costs are much higher and less performance.

Gate 2: Preliminary Design Review

Intro

The product that group 9 has to dissect is a 2.2 Liter GM inline 4 cylinder engine. Group 9 collaborated with group 24 who have the same engine to work on. Group 9 decided to take apart the belt drives, crankshaft, and camshaft. Group 24 took apart the headers and pistons. Group nine used photographic documentation throughout the disassembly/reassembly processes. In addition to the documentation, clear labeling of all the components was used to ensure a smooth reassembly process. Dissection time was about 3 hours spread over 2 days.

Causes for Corrective Action

The dissection of the product went mostly according to plan with only a few deviations. The collaboration with group 24 went smoothly, they began by dissecting their part of the engine first after which group 9 picked up from where they had left off. Everyone within group 9 contributed their part and worked well together, Bryan the dissection leader led the team through this gate. Everyone worked on the product and met on time as outlined in our proposal. Group 9 found that it was a very intricate process and that it would be essential to photograph and document all steps. Sometimes the group would reach a point at which the group was not certain on how to proceed but after much discussion and analyzing group 9 was able to move ahead and continue successfully.

Our one main challenge and perhaps the only noteworthy one (the rest too minor to go into detail with) was removing the camshaft. It seemed as if it would not fit through the openings it was resting in. Bryan did some further research on the subject of camshaft removal and learned that it was necessary to remove the oil pump drive prior to the camshaft. After the removal of the oil pump drive the camshaft was removed with ease. This could have been prevented by previous knowledge of the engine, and how to take apart a camshaft. This delay in completion therefore caused the difficulty level to be increased. This allowed us to stay on track with the group's Gantt chart.

Product Dissection Assessment

Tools Required

The dissection of the product did not require any special tools; various sized sockets, needle nose pliers, and a Torx T-30 were necessary to disassemble the engine. Engine fasteners and bolts were used to suspend the engine which allowed for the dissection of the engine from every angle. Bolts, and torx screws were used as fasteners in the engine.

Difficulty Description

For each step we list a difficulty from 1 to 5. One being easiest, task accomplished on first try with little effort. Five being the most difficult with many attempts required to perform the task correctly. The belt drives, crankshaft and camshaft were easy to take apart because it was mostly bolts holding it together. This engine is intended to be a structured disassembly. Taking it apart is not easy, but it is straightforward.

Dissection Procedure

Group 9 began the dissection of the engine where Group 24 left off. Group 24 dissected the top of the engine including the piston/cylinder system and the header. Group 9 worked on the remaining parts consisting of the crankshaft and camshaft systems which is where the dissection begins.The following steps were used to dissect the engine. Number 1 is the first step and number 17 is the last step. Please refer to the images below for clarity.

1. Removed the (3) water pump pulley bolts with a 13 mm socket [2]

2. Removed the water pump pulley by hand [1]

3. Removed the serpentine belt tensioner bolt with a 16 mm socket [2]

4. Removed the serpentine belt tensioner by hand [1]

5. Removed (3) idler pulley minor bolts with a 16 mm socket [2]

6. Removed (1) idler pulley major bolt and washer with 19 mm socket [3]

7. Removed idler pulley by hand [1]

8. Removed (3) water pump bolts with a 14 mm socket [2]

9. Removed the water pump by hand [1]

10. Removed (2) bolts from camshaft gasket with Torx T-30 [4]

11. Removed (6) bolts from the timing chain cover with a 8 mm socket [2]

12. Removed crankshaft and timing chain cover together by hand [3]

13. Removed (3) camshaft plate bolts with a 10 mm socket [1]

14. Removed the camshaft plate by hand [1]

15. Removed (1) oil pump drive bolt with a 10 mm socket [2]

16. Removed the oil pump drive by hand [1]

17. Removed camshaft by hand see corrective action for high difficulty [5]

Original condition all components intact	Idler pulley and serpentine belt fastener	Crankshaft in the Engine Block
Timing chain cover	Engine block at an angle	Engine block front view

Gate 3: Coordination Review

Intro

Group 9 did not encounter any major issues with the work and management plans. Group 9 met at least once per week to discuss the progress of the Coordination Review. Each member has contributed valuable input to the review. The group as a whole, has met and discussed which member would be focusing on which objectives. Also, the group has made a conscious effort to complete the review in a punctual manner. The groups individuals were assigned specific parts of gate 3. This made working towards finishing the gate much more efficient. The group put all of the individual assignments together and proof-read them to make sure they were sufficient and correct. This made the group use both the strengths of working as a group and as individuals to complete the gate.

Causes for Corrective Action

The group had some road blocks, and had to work around the holiday of thanksgiving. The group would have liked to have the gate done quicker than it happened, yet the group got delayed because of the 5 day weekend. This delay should have been planned into the work schedule that the group had composed. One of the group members email went down, which made communication throughout the group harder. This was over come by communicating via text messaging. These issues were resolved in time for the gate to be completed on time.

Engine Components List

Table 1: GM 4 Cylinder Engine Parts List

Part Number	Part Name	Quantity	Complexity	Material	Function	Manufacturing Process	Image
1a	Water Pump Pulley	1	2	Steel	Converts mechanical energy from the crankshaft through belt drive system and uses the energy to rotate the water pump	Stamped - Machined
1b	13 mm Bolts	3	1	Steel	Holds water pump pulley in place	Machined	Pictured Above
2a	Serpentine Belt Tensioner	1	3	Hard Plastic, Aluminum, Steel	The belt is connected to the drive pulley of the engine creating more tension which supplies power to the belt drive system	Die Cast - Molded - Machined
2b	16 mm Bolt	1	1	Steel	Keeps serpentine belt tensioner in place	Machined	Pictured Above
3a	Idler Pulley	1	2	Steel	It acts a tensioner (keeps tension in system) and a guide for the belt which prevents it from coming off the main pulleys and reduces vibration	Molded - Machined - Milling
3b	16 mm Bolts	2	1	Steel	Keeps idler pulley in place.	Machined	Pictured Above
4	Water Pump	1	4	Steel, Aluminum	Circulates water throughout the engine to prevent it from overheating and reduces friction	Die Cast - Machined - Stamped - Pressed - Molded
5	Crank Shaft	1	5	Steel, Aluminum	Transmits power from the pistons and connecting rods into shaft work	Cast - Machined
6	Timing Chain Cover	1	4	Aluminum	Holds the timing chain against the timing sprocket and protects timing chain from debris	Stamped
7a	Camshaft Plate	1	2	Steel	Holds camshaft in place and prevents debris from entering camshaft	Stamped
7b	10 mm Bolts	3	1	Steel	Holds camshaft plate in place	Machined	Pictured Above
8	Oil Pump Drive	1	4	Steel, Aluminum, Rubber	Secures camshaft in place and drives the oil pump based on input from the camshaft	Cast - Extruded - Machined - Molded
9	Camshaft	1	3	Steel, Aluminum	Timing mechanism used to open and close the valves for the combustion process	Cast - Machined

Component Discussion

Why were different materials used for different components?

The components all must be sturdy enough to withstand the pressures and forces that act on a functioning internal combustion engine. The engine itself is subjected to intense temperatures and pressures. For an internal combustion engine, the list of materials is quite short because the materials must be strong and also cost effective. For the GM 2.2 L 4 cylinder inline engine components, the materials used are:

• Steel
• Aluminum
• Hardened Plastics
• Rubber (used for forming a seal)

The majority of the components are made almost entirely of steel. Tempered steel is relatively low in cost and provides a sturdy structure that will withstand the high temperatures and pressures faced inside the cylinders. Also stands well against high tensions ans shear forces. The second most abundant material used in the components is aluminium. Aluminium is light but more costly than the steel. The aluminum is used in areas that require less weight and do not need to withstand as much forces as the steel. Engineers who designed the components had to find a balance between weight and strength. A component that is in direct contact with the high temperatures and pressures will be made almost entirely of the steel. Components containing aluminium are used to reduce the total weight of the engine without sacrificing stability. Hardened plastics are relatively cheap and easy to make. In the engine, plastics appear in the form of pulleys. The pulleys need to be strong enough to transmit power to and from the various systems without letting the belts slip. Since the pulleys are not indirect contact with the cylinders, they can be made of plastic. The hardened plastics will not melt or deform and are very light, so they are perfect for the pulleys. Rubber is not used much in the selected components. Rubber in the engine is used primarily to form seals. For this reason, rubber functions as a seal in both the oil pump drive and the water pump. The rubber prevents oil from escaping the oil pump drive and water from leaving the water pump. The materials that make-up each component are included on the engine parts list.

Cosmetic vs Functional

All the components listed in our engine are functional. Each component contributes something to the overall functioning of the engine. Engines are typically located under the hood of a car and are thus not meant to be seen. Since engines are hidden, there isn't usually a need to add cosmetic parts.

Complexity

Complexity is used to characterize something with many parts in intricate arrangement also on the difficulty in manufacturing the parts. In the above table (1) is given to the least complex whereas (5) to the most.

Component Analysis

Water Pump Pulley

What material is used?

Steel

Why?

There is a lot of friction within this component creating high temperature and steel is an ideal material when dealing with extreme heat because of its high resistance.

What forces are applied to the component?

There are frictional and tension forces exerted on the pulley.

Force estimate

The tension force is estimated at 50 to 100 N.

Does the material choice affect the manufacturing process?

Yes, certain materials would not be able to withstand such high temperatures and therefore not function properly.

What is the components shape?

The Water Pump Pulley is a circle with raised edges designed to fit on the water pump. It also has holes on the face of it for bolt attachment.

Why?

The circular shape is chosen because this component operates as a pulley using rotational dynamics in which this shape is ideal.

Does the shape affect the manufacturing process?

The circular shape of the water pump pulley is most easily stamped and cleaned-up with light machining. It would be unnecessary to manufacture using other processes.

Why was the manufacturing process chosen?

Stamping was chosen for this product so that it can be mass produced with precision.

How complex is the component?

The part can be easily manufactured by stamping thus not being that complex. Also, a pulley is a very simple machine that transmits power around a circular shape.

Serpentine Belt Tensioner

What material is used?

Hard Plastic, Aluminum, Steel

Why?

Plastic is used for its physical property of not needing any lubrication, it has reduced wear on it and the parts in contact with it, it is inexpensive and corrosion resistant. Aluminum is used because it is soft, light and also corrosion resistant. Steel was used in this component because of its high tensile strength and high resistant against corrosion.

What forces are applied to the component?

There are frictional forces exerted on the tensioner.

Force estimate

The tension force is estimated at 50 to 100 N.

Does the material choice affect the manufacturing process?

Yes. Plastic cannot be machined and must be injected into a mold. The die-cast parts were produced as so because they are easily mass produced whereas the machined parts were done because of a required precision.

What's the components shape?

The component consists of a cylinder with a protruding arm attached to a second cylinder.

Why?

The circular shape is chosen because this component operates as a pulley using rotational dynamics in which this shape is ideal. This reduces friction.

Does the shape affect the manufacturing process?

No the process is unaffected by the shape, because plastic can be molded into a cylinder quite easily. This shape is not a hard shape to mold, so there would be no problems during the molding process.

Why was the manufacturing process chosen?

Plastic can be easily molded, whereas metals can be easily machined and die cut using appropriate tools.

How complex is the component?

This is one of the most complex component of our product as it's manufactured from three different materials, it consists of a cylinder with a protruding arm attached to a second cylinder, which operates as a pulley for which the shape is ideal.

Idler Pulley

What material is used?

Steel

Why?

Steel was used in this component because of its high tensile strength and high resistance against corrosion.

What forces are applied to the component?

There are tension forces present.

Force estimate

The tension forces are estimated at 50 to 100 N.

Does the material choice affect the manufacturing process?

The same results can be achieved using a different metal as well.

What's the components shape?

The Idler Pulley is a circle with raised edges. It also has holes on the face of it for attachment via bolts.

Why?

The circular shape is chosen because this component operates as a pulley using rotational dynamics in which this shape is ideal.

Does the shape affect the manufacturing process?

No, the shape of the idler pulley does not make it so it can not be milled, or molded. Machining is also not a problem with this shape.

Why was the manufacturing process chosen?

Milling was required for the holes, which reduces the weight. Molding parts are easily and accurately reproduced. Machining was used to produce a smooth finish to reduce friction

How complex is the component?

This component is fairly simple as it consists of just one circular part with holes in it. It can be easily molded and the holes can be milled accurately.

Water Pump

What material is used?

Steel and Aluminum

Why?

Aluminum is used for it's soft, light and also corrosion resistant properties. Steel was used in this component because of its high tensile strength and high resistance against corrosion.

What forces are applied to the component?

There are tension forces present

Force estimate

These forces are estimated at 50 to 100N

Does the material choice affect the manufacturing process?

Yes, steel is harder to machine than aluminum because aluminum is softer and needs to be more precise.

What is the components shape?

A triangular mount with a small shaft attached to a small rotor.

Why?

This is required because it needs to take the rotational energy through the shaft to move water throughout the cooling system.

Does the shape affect the manufacturing process?

Yes, the intricate shape required, casting, pressing, machining, and molding to manufacture.

Why was the manufacturing process chosen?

The steel components were cast and pressed, the shaft was machined, and the rotor was molded. These components are most accurately and cost effectively produced in this manner.

How complex is the component?

This component is very complex because it's made of two different materials as well as it would be an intricate process to construct the required shape for the component.

Crankshaft

What material is used?

Steel and Aluminum

Why?

Steel was used in this component because of its high tensile strength and high resistance against corrosion. Aluminum is used for its soft, light and also corrosion resistance properties.

What forces are applied to the component?

The weight and movement of pistons due to combustion.

Force estimate

From our calculations, the force is approximately 4000 N.

Does the material choice affect the manufacturing process?

Steel and Aluminum are most workable through machining processes.

What is the components shape?

Several cylinders and circular plates of various diameters offset from a center axis.

Why?

The cylinders and plates separate and time the pistons.

Does the shape affect the manufacturing process?

Yes, many of the components can be cast but need to be machined for precision.

Why was the manufacturing process chosen?

Yes, a smooth finish is required for the cylinders to reduce friction between them and the connecting rods of the pistons.

How complex is the component?

This is the most complex component as it has several cylinders and circular plates of various diameters, it also needs to have a smooth finishing to reduce friction.

Timing Chain Cover

What material is used?

Aluminium

Why?

Aluminium is used for its soft, light and also corrosion resistant properties.

What forces are applied to the component?

The force on this component is the weight of the pulleys.

Force estimate

The pulleys weigh approximately 10 to 20 N combined.

Does the material choice affect the manufacturing process?

Yes, because aluminum's softness makes it ideal for stamping.

What's the components shape?

This is an oval with a protruding circle at one end.

Why?

This is meant to cover the timing chain and provide support for the pulleys.

Does the shape affect the manufacturing process?

Yes, because this shape cannot easily be machined or cast, it is much easier to stamp this component.

Why was the manufacturing process chosen?

The timing chain cover does not need to be smooth and aluminum is easily stamped and reproduced.

How complex is the component?

This part is not that complex as it can be easily stamped and also it need not to be smooth.

Camshaft Plate

What material is used?

Steel

Why?

Steel was used in this component because of its high tensile strength and high resistance against corrosion.

What forces are applied to the component?

The bolts holding plate in place.

Force estimate

These are approximately 3 N.

Does the material choice affect the manufacturing process?

No, it is still able to be stamped with it being steel.

What's the components shape?

This component is a circle with three equally spaced protruding miniature circles.

Why?

The protruding circles are present for attachment purposes.

Does the shape affect the manufacturing process?

This shape is most easily and efficiently stamped.

Why was the manufacturing process chosen?

This component is most effectively and mass produced in the stamping process.

How complex is the component?

This is a fairly simple component as it can be stamped easily and efficiently.

Oil Pump Drive

What material is used?

Steel, Aluminium and Rubber

Why?

Aluminium is used for its soft, light and also corrosion resistant. Steel was used in this component because of its high tensile strength and high resistance against corrosion. Rubber is used for its ability to create a firm seal.

What forces are applied to the component?

There are rotational forces present.

Force estimate

The rotational force is estimated at 30 to 40 N-m

Does the material choice affect the manufacturing process?

The gear was cast, the steel shaft was machined, and the rubber was molded into a ring.

What's the components shape?

There are several cylinders attached at their central axis with a protruding edge for attachment via bolt. There is also a main gear.

Why?

The gear's purpose is to attach to the camshaft, hold them in place and drive the oil pump.

Does the shape affect the manufacturing process?

Yes, this gear needed to be very precise, which caused it to be machined.

Why was the manufacturing process chosen?

Machining provides a smooth surface for less friction of the gear.

How complex is the component?

This component is complex as it uses three different materials for manufacturing, the gear, the steel shaft and the rubber ring. Its shape also has to be very precise and smooth to limit friction.

Camshaft

What material is used?

Steel and Aluminum

Why?

Aluminium is used for its soft, light and also corrosion resistant. Steel was used in this component because of its high tensile strength and high resistance against corrosion.

What forces are applied to the component?

There are rotational forces and forces due to the push rods

Force estimate

The estimated rotational forces are 100 to 150 N-m and the push rod forces are estimated at 50 to 100 N.

Does the material choice affect the manufacturing process?

Yes, these metals are easily machined and cast. Aluminum is used more in the machining whereas the steel components are cast.

What is the components shape?

The camshaft is composed of a long shaft with several lobes placed along the length of the camshaft.

Why?

The placement of the lobes is determined by where the pushrods are placed.

Does the shape affect the manufacturing process?

The camshaft is generally made on a lathe but, the lobes are cast and machined separately.

Why was the manufacturing process chosen?

Lathes produce smooth cylindrical finishes.

How complex is the component?

This is a fairly complex component as it's composed of a long shaft with several lobes along its length. It has a smooth cylindrical finish which has to be cast and machined separately.

Design Revisions

The design changes Group 9 is suggesting are intended to make the engine lighter, cost effective and performance driven.

• Camshaft configuration

• In the GM 2.2L Four Cylinder Inline engine the camshaft configuration is a pushrod system. Group 9 would recommend to the manufacturer a switch to an overhead camshaft system either single (SOHC) or double (DOHC). The current pushrod system is less efficient than an overhead cam system.

• Pushrod timing systems have an in-block camshaft located below the cylinders. Thin rods of metal called pushrods which are usually 8-10 inches in length ride on top of the lobes of the camshaft. As the camshaft spins the lobes push the pushrods up which move the rocker arms up and open the valves into the cylinder. In the pushrod system more material is needed to make the pushrods and the timing of the valves is not at its peak efficiency. Pushrods add mass to the system and increase the load on the springs which greatly limits the performance of the engine. A camshaft that is mounted above the cylinders and directly next to the rocker arms is more desirable.

• Single Overhead Cam (SOHC) systems have the camshaft located directly above the cylinders and next to the rocker arms. Not only does this improve performance but it reduces costs and the total weight of the engine. Without the pushrods the chance for failure is greatly reduced and the energy of the camshaft is directly exchanged into the rocker arms and valves. The overhead camshaft system is just plainly simpler but at the same time more efficient. In overhead camshaft systems the timing must be perfect otherwise the pistons may hit the valves. This problem is avoided by the timing chain which connects the camshaft(s) to the crankshaft.

• Double Overhead Cam (DOHC) systems are almost exactly the same as the SOHC system except instead of one camshaft per head there are two. For example in a V-4 engine there would be two overhead cams for a SOHC system or four overhead cams for a DOHC system. In a V shaped engine there are two heads so there must be at least one cam per head. The GM 4 cylinder inline could have either one or two overhead cams because there is only one head. The major disadvantage to two cams per head would be an increase of weight but at the same time it is increasing performance. A balance between weight and performance must be made for the best efficiency. Two cams are preferable for performance and one is preferable for keeping costs down. Overall, a change from the pushrod system to an overhead mounted cam would improve the engines functionality, reliability and reduces maintenance.

• Cylinder/Piston Size

• One of the biggest performance improvements that can be made to a stock engine like the GM 2.2L Four Cylinder Inline engine is to increase the cylinder and piston size.

• The concept of increasing the enclosed volume of the cylinder to improve performance is widely known in engine manufacturing. The way a company would increase the size of the cylinder is to take the bare engine block and bore out the cylinders with a mill. From intuition, the more air that can be compressed and ignited with fuel, the better the engine will perform. Cylinders can be bored with great precision by a milling machine. One small mistake in this process would result in a major problem with the combustion process. The pistons must fit perfectly within the cylinders creating limited friction and an impenetrable seal of the combustion chamber. If this is not achieved then either the piston and cylinder wall may crack or the combustion process will be incomplete or highly inefficient.

• An advantage of the increased cylinder size is more performance out of the same engine block. When the cylinder is bored it must still have enough cylinder wall between each cylinder to prevent the engine block from cracking. The pressures inside of an internal combustion engine are enormous so the cylinders must have enough strength to overcome all the forces applied to them.

• The biggest disadvantage to boring the cylinders wider is cost. Since the milling process is highly precise it is quite costly. However, if performance is an issue to the company then this is an improvement that should be considered. Another issue with a larger cylinder is the limitation based on the piston sizes. The pistons must ride perfectly within the cylinders so the size of the cylinder is based on the size of the piston.

• A precise engine means greater performance but more cost. The reliability and functionality will greatly increase if the cylinders are precisely milled. Increasing the cylinder size will remove material but adding larger pistons adds mass. The balance between cylinder and piston size will keep the weight about the same. If the manufacturer can afford larger, more precise cylinders the design of the engine will be improved.

• Pulleys

• The two main pulleys on the engine are the idler pulley and water pump pulley. They are both made of steel and have vertical grooves along the outside where they come into contact with the belt. Group 9 is suggesting as a design revision the idler pulley and water pump pulley be made completely of aluminum and a different design for the grooves.

• A pulley’s main function on the engine is to transmit power to and from various components. It is important that the pulleys be lightweight and has enough grip to ensure the belt does not slip.

• The idler pulley acts as a guide and tensioning device for the belt. If the idler pulley was made of aluminum it would weigh less than steel and there would be no need for the extra holes made in the original. The manufacturer cut holes in a circular pattern to reduce the weight because the steel is very heavy. However, aluminum is already lighter than steel and is strong enough to hold the belt system in place.

• The water pump pulley takes the energy from the crankshaft and idler pulley to turn the water pump. A water pump is attached to the backside of the water pump pulley and as the belt spins the pulley, the water pump is driven. Efficiency of the water pump depends on the water pump pulley so to make the pulley out of aluminum will make it lighter and faster. The aluminum is costly but in this case worth it.

• For both pulleys the vertical grooves are not the most efficient way of creating a solid grip of the belt. If the belt has horizontal grooves then the pulleys should have horizontal grooves for the belt to fit into. There is a very small chance of the belt slipping if the design includes matching grooves for the pulleys and belt. The grooves will not increase costs and the reliability and functionality will greatly increase.

Solid Modeling

All of the solid modeling was done in Pro Engineer 4.0 because of its common use and convenience. The parts chosen were the camshaft, oil pump drive and bolt, and serpentine belt tensioner. The parts were chosen for their complexity and for their importance in functioning of the product. The camshaft and the oil pump drive were chosen for their unique interaction. The camshaft and the oil pump drive function simultaneously to drive the oil pump. The oil pump drive bolt functions to secure the oil pump drive and thus is an important part of the process. The serpentine belt tensioner also plays a key role in the functioning of the system. The serpentine belt tensioner creates tension to supply power to the belt drive system.

Parts

Camshaft Modeled in Pro Engineer Wildfire 4.0.

Oil Pump Drive Modeled in Pro Engineer Wildfire 4.0.

10 mm Oil Pump Drive Bolt Modeled in Pro Engineer Wildfire 4.0.

Serpentine Belt Tensioner Modeled in Pro Engineer Wildfire 4.0.

Assembly

Assembly Picture 1 in Pro Engineer Wildfire 4.0.

Assembly Picture 2 in Pro Engineer Wildfire 4.0.

Assembly Picture 3 in Pro Engineer Wildfire 4.0.

Assembly Picture 4 in Pro Engineer Wildfire 4.0.

Assembly Picture 5 in Pro Engineer Wildfire 4.0.

Assembly Picture 6 in Pro Engineer Wildfire 4.0.

Engineering Analysis

Problem Statement: A superheated piston becomes warped inside a cylinder of an internal combustion engine. During the combustion phase of the cycle, the piston begins to move down from the ignition of the air and gas mixture by the spark plug, when it becomes jammed only 1 cm down from its original position. The deformed piston caused a stoppage in the system, which creates a large buildup of pressure inside the cylinder. The built-up pressure over one cycle of the engine is to be determined.

Diagram:

Assumptions:

• The original piston/cylinder device is frictionless

• The frictional force of the jammed piston/cylinder device is always greater than or equal to the force of the explosion

• Original pressure inside cylinder = P1 = 1 atm = 101.325 kPa

• Original temperature inside cylinder = T1 = 20°C = 293 K

• Adiabatic combustion temperature of gasoline = T2 = 2300K

• Cylinder r = 4.4 cm

• Cylinder h1 = 10.0 cm

• Ideal gas

• Rigid tank

Governing Equations: P_1*V_1/T_1 = P_2*V_2/T_2

Vcyl. = hπr^2

Calculations: V_1 = (0.10 m) π (0.044 m)^2 = .000608 m^3 V_2 = (0.11 m) π (0.044 m)^2 = .000669 m^3

(P_1 V_1)/T_1 = (P_2 V_2)/T_2 → P_2= (P_1 V_1 T_2)/(T_1 V_2 )=((101.325kPa)(.000608 m^3 )(2300 K))/((293 K)(.000669 m^3))=722.86 kPa

Discussion: In this problem it is expected the pressure after combustion will be much higher than at the original state. Through the calculations we proved this to be true. Since the piston becomes jammed, the pressure that is created during combustion is not fully transferred into mechanical energy because the piston is not moving. This is a problem that can occur in any internal combustion engine if not maintained well. We assumed that the mixture of gasoline and air is an ideal gas acting in the rigid tank known as the piston cylinder. The initial state is characterized by standard temperature and pressure after the air intake. The temperature at which gasoline combusts was found to be around 2300K according to Ecen.com. After the combustion of the gas and air mixture, the piston moves only 1 cm therefore only changing the volume by slight amount. Normally the piston gets shot down due to the rapid increase in pressure which allows the pressure to decrease again. Since the piston is stuck and unable to move, the pressure builds up. This pressure is determined to be 722.9 kPa.

Engineering Analysis Uses: Engineering analysis is used all throughout the design and testing stages. When designing any product time must be taken to analyze every part. In order for a part to function properly one must consider its purpose and function in the overall product. One must use engineering analysis to determine forces and energies acting on it. One must also design the product to meet consumer wants such as aesthetics (although aesthetics don't typically come in to play with things like car engines). In the case of the example above engineers need to account for the possibility of the piston getting stuck. They need to make a failure modes and effects analysis, like below, to determine the likelihood of the problem and prevention. Then they must achieve a certain factor of safety. Even in testing engineering analysis is used. One must interpret the results of the test with engineering analysis to determine whether they have to return to the design stage (does not suffice requirements) or can move on with production.

Failure Modes and Effect Analysis: Few pistons simply fail. Most are damaged by a faulty operating environment. These conditions include lack of lubrication, abnormal combustion, the presence of debris within the engine, and clearance issues that lead to physical contact between the piston and another part. Also if the engine injection system is delivering the wrong amount of fuel, at the wrong time or for the wrong duration excessive heating can occur or even erosion. In order to prevent heat build-up that can lead to piston damage, it is important the correct level of lubrication reaches the piston at the skirt and piston pin. Another possibility of piston failure can be caused by contamination from the air intake. Such things can cause scuffing and eventually result in piston failure. Piston failure doesn’t really occur frequently but can occur over time. It can be avoided if caught in time. Drivers can notice this as it can cause fluctuations in oil pressure, higher than normal operating temperatures, unusual noises and change in fuel and oil consumption. Once damaged pistons reach failure the car may be rendered unable to be driven creating a huge safety concern.

Gate 4: Critical Project Review

Product Reassembly Plan

Group 9 begins their reassembly process with an empty engine block; their tools which includes a socket set, rubber mallet, and Torx screwdriver; and all of the disassembled components mentioned below. For each step a difficulty from 1 to 5 was assigned. One being the easiest, task accomplished with little effort, and five being the most difficult with many attempts required to perform the task correctly.

Empty engine block

Table 2: Product Assembly

Step	Procedure	Difficulty	Image
1	Reattach the water pump with (2) 13 mm bolts using a socket.	1	Reattached water pump
2	Reattach the water pump pulley with (3) 13 mm bolts using a socket	1	Reattached water pump pulley
3	Replace camshaft by hand by inserting it into the slot and fixing it in place with a rubber mallet.	2
4	Reattach the oil pump drive by twisting it into slot by hand. Insert (1) 10 mm bolt to secure it with a socket.	1	Reattached oil pump drive
5	Reattach camshaft plate with (3) 10 mm bolts using a socket.	1	Reattached camshaft plate
6	Reattach camshaft gasket with (2) Torx screws using a Torx screwdriver.	1	Reattached camshaft gasket
7	Reattached timing chain guide.	2	Reattached timing chain guide
8	Insert the crankshaft and timing chain cover simultaneously while ensuring to fit the peg of the camshaft into the gear of the timing chain.	5	Crankshaft inserted into engine block Timing chain cover situated in place
9	Reattach timing chain cover with (6) 8 mm bolts and (1) 1 inch bolt onto the gear using a socket.	1
10	Reattach idler pulley with (3) 16 mm bolts and (1) 19 mm bolt using a socket..	1	reattached idelr pulley
11	Reattach the serpentine belt tensioner with (1) 16 mm bolt using a socket.	1	reattached serpentine belt tensioner

Engine assembled

front view completed

top view completed

Reassembly Analysis

Does your product run the same as it did before you disassembled it?

When we were assigned the GM inline four cylinder engine as our product, it was not in working condition. After reassembling the product back to it's original state we were able to rotate the crankshaft with all of it's connected parts rotating simultaneously as well. This made sure that the product was in the same running condition as assigned initially.

What were the differences between the disassembly/reassembly processes? Were the same sets of tools used? Were you able to reassemble the entire project?

For the most part, the disassembly and reassembly processes were almost exact but in reverse order except for a few alterations. Reinserting the crankshaft turned out to be a very difficult procedure and quite different from how we extracted it in the disassembly. When dissecting the engine, the crankshaft had to be maneuvered and removed by hand which did not prove to be very difficult. Reassembling it however, was a precise and tedious process. The heavy weight of the crankshaft/timing chain cover component complicated things when we tried to reinsert it and had to align it exactly to fit correctly. It was also slightly tricky to match the timing chain gear to its chain correctly while simultaneously placing the crankshaft in its slot. Besides the addition of the rubber mallet, the same tools were required for the assembly of the engine which include a set of socket wrenches and a Torx screwdriver. After approximately three hours, Group 9 was able to successfully reassemble our half of the engine just as we were presented with it.

Are there any additional recommendations your group would make at the product level (operation, manufacturing, assembly, design, configuration, etc.)?

The main recommendation Group 9 is suggesting for the GM 2.2L 4-cylinder inline engine is an overhead camshaft configuration. As mentioned in the design revisions an overhead camshaft configuration is more efficient and produces more power than an in-block camshaft. Also, disassembly and reassembly of the camshaft and its surrounding components is much more difficult than an overhead mounted camshaft. Group 9 experienced the difficulties of reassembly when the camshaft would not line up properly with the timing chain gear. It is much more difficult to make adjustments when the camshaft is sitting deep inside the engine block than sitting on top of the headers. Group 9 had to make small adjustments to make the timing chain gear fit on the end of the camshaft and it would be easier to adjust on the outside of the engine block.

References