Gate 5 - Delivery
Gate 1: Request for Proposal
Our group has been assigned a General Motors six cylinder engine, shown in Figure 1. In order to reverse engineer our motor we plan to start by taking photos and recording the position of everything on the motor, as is. We will start by removing any subsystems such as electrical wiring harness, air intake system, exhaust systems, starter motors, charging systems, and the ignition system if they are present. This will be done by loosening any bolts that connect the subsystems to each other or to the engine block and heads. Also some sensors, like those on the intake manifold, will have clip connectors. These connectors and other sensors will have to be taken apart with extreme care as not to break them. With all bolts loosened and sensors removed, we should be left with the engine block with rotating assembly inside, and the cylinder heads, complete with valve train intact.
From only inspection of the exterior we plan to next, take apart the valve train. This will first consist of the removal of the cylinder heads from the engine block. After having loosened the bolts on the head studs, the entire cylinder head assembly can be removed and put on a work bench area in order for easier dissection. With the cylinder head right side up, the rocker arms must be removed to get into the rest of the valve train, this will be done with either a socket wrench or Allen wrench depending on the bolt. The next step is to use the valve spring compressor to compress to valve springs, allowing for removal of the valve seats and retainers depending upon the valve train design.
In order to successfully dissect our automobile engine, we have decided to give certain positions to each person in our group. With these positions well be able to identify the specific roles of each person in our group. But even though a specific role is given to a person, we will all try to work an equal amount on the project so that we produce a report of high quality. The roles of each person are as follows.
and Tanner Kahm
|Matthew Egan||Technical Report Editor||
|Samuel Kim||Communication Liason||
- E-mail- firstname.lastname@example.org
- Phone number- 845- 645- 0702
|Jasmine Lawrence||Project Manager||
In order to complete the project in a timely fashion we have decided to meet twice a week on Tuesday and Thursday in the Capen Library or in the lab located at Furnas 621. If more meetings are needed we will schedule them accordingly with everyone’s schedule. The plan during the labs is to dissect the engine as efficiently as possible while learning about each subsystem noted in the Product Proposal (rotating assembly, valve train, energy transformation systems, engine control systems). We will be starting with the top of the engine taking apart each section of the head and then the block so we can view the inner parts of the engine. First, we will look at the main rotating assembly and how the crankshaft works with the connecting rods, pistons. After this, we will move to the valve train and look at the camshafts, valves and several other components in this system. And then we will move on to observe the energy manipulation components of the engine like the water and oil pumps and alternator. During our meetings and time in labs, we will complete the dissection of the engine while learning about each system and subsystems as well as re- assembling the engine in the state given to us. If there is a conflict within the group, we will all come together and discuss the issue that is at hand and we will handle it in a fair, democratic way that would hopefully do away with the problem within the group.
The following outline is a schedule of our planned meetings:
Gate 2: Due 10/26/11
- October 11th , 13th , 18th and 21st
Gate 3: Due 11/14/11
- November 1st , 3rd and 10th
Gate 4: Due 12/2/11
- November 17th (21st if necessary) and 29th
Gate 5: Due 12/16/11
- December 6th and 8th
At each of these meetings we will work to accomplish as much as possible, especially in the lab, so that we can meet the requirements of each gate in a timely fashion. We will continue to communicate effectively via email, text messaging and phone calls to solve any possible conflicts as well as answering any questions that may arise in the whole project.
The group decided a Gantt chart would be a simple and effective way to plan the semester's work load. Figure 1, shown below was created using Gantt Project.
Figure 1: Gantt Chart used to organize work.
The Vortec 4300 which was based off the Chevrolet small-block v8, was developed by General Motors in the 1980’s. During the 1960’s, American vehicle manufacturers had a large focus in their performance cars, or muscle cars. Their goal was to create as much power as possible in light weight, two-door cars. This resulted in the three major car corporations, designing engines with large displacements. These engines not very fuel efficient, but this was not much of a concern at this time. During the 1980’s the car manufactures began focusing on producing more fuel efficient engines. This can be done by decreasing the number of cylinders, and with that, the displacement. GM designed a 4.3 Liter, six cylinder engine for use in light duty trucks and SUV’s. This engine produced enough horsepower and torque to be a feasible option for use, but also increased the fuel efficiency. This allowed consumers to continue their usual usage, but use less fuel. The 4.3 Liter, six cylinder, or Vortec 4300, was also cheaper to manufacture than a larger eight cylinder engine due to less material needed, as well as less internal parts. Because of these characteristics, it was offered in more than ten vehicles available in North America. Through its lifespan of more than 15 years, it went through a few minor design alterations but the same design remained the same.
The General Motors Vortec 4300 engine was typically an engine design for small to medium sized trucks, sport utility vehicles, and vans but also made some appearances in large passenger sedans. The wide range of vehicles it was used in portrays the engine's versatility in the automobile market. Being put into generally larger vehicles, the engine has a higher output (around 200 horsepower depending on the model) than smaller four cylinder engines. This shows that the intended use of the engine was to provide sufficient power to these larger vehicles. The engine also had a high specific torque in order to haul loads in the given vehicle as well as to provide an acceptable rate of acceleration in heavier consumer vehicles. This engine was designed for use in typical consumer automobiles, but also had some usage in different professional machinery. This is evident in the tasks it can perform better than some other engines, such as towing or hauling loads. Due to the Vortec's high torque, along with its' wide torque band, the engine can handle extended periods of high load such as those experienced during towing. The engine also does this while being more economical than a typical eight cylinder engine.
In the Vortec 4300, the electrical system is a major contributor to the overall operation as shown in Figure 2. Most modern engines have very technologically advanced systems to control and monitor various operations of the engine. These are all controlled by electricity which is provided by the battery. Electrical energy is used to communicate different conditions to the engine's computer, also known as an engine control unit or power train control module. Communication is essential for the engine's computer to monitor and then adjust different systems of the engine accordingly for optimal operation. The electrical system includes the engine control unit, all of the sensors used to monitor engine operation (knock, air fuel ratio, camshaft, crankshaft, mass air flow, manifold air pressure, and temperature sensors) as well as the alternator. As a whole the electrical system is responsible for complete control and monitoring of the engine. The overall function of an engine is to create rotational energy. The system directly involved in this conversion would be the rotating assembly of an engine. The rotating assembly consists of the pistons, piston rings, connecting rods, pins, crankshaft, and bearings. In this subsystem the energy of the gasoline is released along with the heat energy of the ignition and energy of the air in the form of a combustion. Called the Otto Cycle, the combustion phase causes the piston to then have linear motion, which is converted to the rotational energy of the crankshaft. Along with the rotational energy created, heat energy is also created but not for any use of the engine. The rotational energy of the crankshaft that is created is used by other subsystems as shown in Figure 2. The amount of rotational energy created depends on a number of factors within the rotating assembly of an engine. For energy to enter the rotating assembly system, it must first pass through the valve train. The valve train includes all of the mechanical systems of the cylinder head, which are the camshafts, , rocker arms, intake valves, exhaust valves, valve springs, seats, and seals. Before the chemical energy of the gasoline can enter the combustion chamber, it mixes with air to form an air fuel mixture, which then is sucked through a vacuum into the cylinder before it combusts to form the rotating assembly’s rotational energy. To control the air fuel mixture’s entrance into the cylinder, a camshaft is used to trigger the opening of an intake valve. The camshafts operate by chain from the rotational energy of the crankshaft as referenced in Figure 2. While energy flows through all of the subsystems of an engine, there are many output energies that are byproducts of the intended use, to create rotational energy. A main byproduct of an engine's energy flow is the heat produced by the Otto Cycle. This heat energy takes a few forms, including the heat energy of the exhaust gases exiting the cylinder after combustion, and the heat energy of the cylinder after combustion. With heat energy being such a large byproduct of an engine's entire process, there are multiple subsystems associated with the dissipation of this unwanted heat. The heat energy produced is dissipated through the cooling subsystem which includes the coolant, oil, water pump, oil pump, coolant passages, oil passages and radiator. Heat energy is transferred to the coolant via the water passages in the engine block. The coolant is then cycled through to the radiator by flow energy of the water pump, and the heat energy is then transferred to the outside air via a radiator. The heat energy is transferred by the oil in the same manner.
A majority of this engine is made out of cast iron. This includes the block and cylinder heads which are visible from the outside. The intake manifold is made of cast aluminum and composite metal. The internal parts that are not currently visible include the crankshaft, which is also cast iron, and the connecting rods are made of powder metal. Cast iron is a heavy material which is a drawback when considering the rotational mass, but it is quite durable. This will allow the engine to run for a long period of time, assuming it is maintained well.
User Interaction Profile
The user of the Vortec 4300, could also be referred to as a consumer who purchased a vehicle containing the engine, interacts with the engine in a few unique ways. The first would be in the actual use of the vehicle for transportation. The engine is used for the rotational energy it produces which is converted to translations energy by the car's other systems. Therefore the user is interacting with the engine through starting cycles, throttle inputs, dashboard gauges and other translational aspects. The user also experiences other operational effects of the engines such as noise, exhaust gases, and heat. The product is relatively easy to use in a automobile, not having any other inputs besides throttle and only consuming oil and fuel. This makes operation easy for the average consumer. Regular maintenance consists of changing the oil, changing spark plugs, changing the air, oil and fuel filters. Being fuel injected, there are no carburetors to maintain which makes the Vortec much more user-friendly than other engines. Most of these jobs are able to be done by the average consumer with a small amount of written assistance.
Product Alternative Profile
The engine was originally introduced in 1985 in the Chevy Astro van and C/K pickup trucks. In the Astro, it was a larger alternative to a 2.5 Liter inline four cylinder. In the pickup, it was the smallest engine available with options being a 5.0L, 5.7L, and 7.4L gasoline engines. In each application, it offers different advantages and disadvantages. In the Astro van, as the larger alternative, it was less fuel efficient, thus more expensive to run. As an additional optional, it cost more to purchase a van with the Vortec 4300 as opposed to the inline four. Since it was a larger engine, it did produce more power, which may have been a necessity for some. On the other hand, Chevrolet did not offer a smaller engine in the C/K pickup. The Vortec 4300 was the base model engine, which means the customer did not have to pay to have this engine as an option. It provided better fuel efficiency than the other engine options, but the smaller displacement resulted in the least amount of power offered for the C/K trucks. This may have been optimal for those who did not need to haul or tow anything, but others may have needed more power for their intended use. The consumer would have to evaluate their needs and decided if the Vortec 4300 would fit their demands.
Gate 2: Product Dissection
In Gate 2 we will describe the exact process our group underwent in order to dissect our engine. This will be accomplished by giving the steps of dis-assembly in order of the major subsystems. At the end of each process to the subsystem we will also discuss the subsystem's relation to the overall function of the engine, how it is connected, and also the factors that contribute to the design of the subsystem. This Gate will describe, in detail, some of the challenges our group faced and how those challenges were handled. Overall this Gate displays a detailed outline as to how we as a group dissected the major subsystems and their components, and how each interact individually as well as with one another for successful functionality of our engine.
Project Management: Preliminary Project Review
The original plan for taking apart the engine did not work because we had to base most of it on past experience, what we could find on the internet, and what we could see from the outside of the engine. While some things worked really well, such as the removing the pistons, others, mainly the valve springs, we could not do because of lack of proper tools. I feel that if we had experience with a similar engine to this GM Vortec V-6 we could have had a more accurate process for taking apart the engine. Another issue in our original plan was the fact that there were two groups using the same engine, which restricted removing the intake manifold and other components because there is only one. It also inhibited us from taking parts off that there were multiple of but were in the way of removing other parts; such as valve train and pistons. This could have been avoided with better planning with the other group.
For the most part the process of taking apart the engine was removing bolts from a specific part, starting with the air intake system; including the throttle body the intake manifold, the distributor, and fuel injectors. After that we removed the valve train starting with the cover, then disassembling the rocker arms, followed by exhaust manifold, and finally removing the cylinder heads. Next we removed the cooling system. After breaking down the water cooling system into water pump, the thermostat, and the electric water sensor we removed the engines timing system; we started by removing the timing chain cover to unseat the timing chain so we could remove the crankshaft which is in the way of the timing gears and the camshaft. To remove the crankshaft we had to start by removing the oil systems starting with the external oiling system, including an inlet/outlet for oil that may go to an external oil filter, and then we removed the oil pan and the internal oiling system. With the oil system removed we started removing the rod end caps and the rod bearings from the crankshaft so we could remove the crankshaft. With the crankshaft out of the way we could remove the piston from the rotating assembly and the timing gears and the camshaft. Once we got to this point we only had solid engine block left, which we could not break down any further, so we started following out exact process which we had written down in reverse to get the engine into the same condition we found it in.
Resolved Group Challenges
During the dissection process one of the first obstacles we came across was removing the pulley that was connected to the cam shaft unit in order to remove the timing chain cover. The pulley could not be dissembled without the use of a pulley-puller which we did not have at our disposal so we had to find an alternate way to somehow remove or displace the timing chain cover so that we could dissect the timing chain and its gears. After lifting the cam shaft unit up and out a little we were able to, after removing all of its bolts, rotate the cover upward enough so that the chain and gears could be accessed and then removed. In this portion of the dissection we were able to resolve our challenge by utilizing simple problem solving skills and team work to alter our previously planned dissection process and to get the task at hand complete.
Another challenge we faced while disassembling was the removal of the camshaft. After taking off the one head of the engine and all the corresponding parts to follow, such as the gaskets, pumps, and pistons, we thought the camshaft should be able to slide right out since it was planned to be one of the last steps in the dissection process but it did not. The camshaft seemed to be stationary, being held in place by what had to be something within the other cylinder head unit. From this we took off the other head cover and removed its pushrods which allowed our camshaft to move and be rotated outward for removal. Getting to the what we thought were the final stages in the dissection of our engine we found that although a V-6 is symmetrical for the most part there are components, such as the camshaft, shared and that both sides hold such parts into place.
Reassembling the engine came across much easier than dissembling it. The only major obstacle we ran into while putting the engine back together was replacing the pistons with the piston rings attached. One of the three removed went back in with no problem and the piston ring attached but the other two went back in challenge-free right up until where the ring was now semi-attached. In order to reassemble the pistons with their rings we had to use a piston compressor to hold the rings in place while we put the pistons back in. Successfully seeking the proper tool allowed our challenge to be resolved in a timely manner with no other unsafe or extreme attempts made by our group members.
With all the challenges we faced, we as a group showed not only our teamwork skills but also our problem solving skills and were able to resolve the major issues with the tools and knowledge that we possessed. We took prior knowledge and implied ideas to come up with possible solutions to our obstacles until we found safe and logical resolutions.
Unresolved Group Challenges
During our dissection, we occasionally ran into small problems that could not be fixed. We were still able to successfully complete the dissection but these were some issues that we ran into in the process.
One instance is when we discovered that some parts of the engine were missing bolts that kept pieces together. For example, when removing the oil pan, there were two bolts missing that helped to keep the oil pan on. But the oil pan was able to stay on even with the absence of the bolts. This is may not have been a problem at the time but if that were to happen when the engine is functional, the oil pan might fall off. Another instance where there were bolts missing was on the intake manifold and around the block of the engine. There were several bolts that were not identifiable because they weren’t holding anything together and the bolts missing on the manifold, like the oil pan, were not needed to keep it on but in the event the engine were to be run, there would most likely be problems with its rigidity.
Another issue that we ran into were the valves and valve springs. We were not able to take the valves out during the dissection and examine them further. We were able to remove the head from the engine block to reveal the valves but that is as far as we were able to go. We were not able to remove the valves because of the lack of a valve compressor. A valve compressor would have allowed us to relieve the pressure from the valve springs and then remove the valves. Hopefully we will be able to obtain a valve compressor and further analyze the valve train and have a more thorough dissection.
The last issue we had was with the fuel injection controller. We were not able to remove it from the intake manifold and see what was inside of it. The controller was connected to the fuel injector and the fuel lines but for some reason we were not able to remove the controller itself away from the manifold. This was only a slight issue because we were still able to look at the intake manifold even though the controller was still on top of it and we were able to remove everything else on the manifold.
Even though we ran into these minor issues, we were still able to complete the engine dissection and learn about the inner workings of the engine as well as how each part works in harmony with each other.
Product Archaeology: Product Dissection Process
This section provides an in depth process as to how our individual group proceeded in the task of dissecting the engine. Each step includes the information necessary to perform the given task, however some basic hand tool operations are necessary. This includes operations such as loosening a threaded fastener, accomplished by turning the tool counter-clockwise. The majority of the sockets used can be operated with a 3/8 inch socket wrench however a 1/4 inch socket wrench could also be useful. Along with each step a rating will be provided describing the difficulty of each task. Chart 1 provides a brief summary of the difficulty scale. This section also provides a short discussion on if individual part being removed is intended to be removed, or if it is intended to be a permanent part of the engine.
Each subsystem of the Vortec 4300 is an integral part of its ability to function. Without the air intake, valve train, cooling system, timing system, or rotating assembly, the engine would not be able create power for an extended period of time. The rotating assembly is located in the center of the engine and connects the two sides and the accessories of the engine. The main part of the assembly is the crankshaft, which is arguably the most important part of an engine. The crankshaft, shown in Figure 17, uses its rotational mechanical energy to propel the vehicle forward and to control other functions of the engine.
Step 1: Air Intake System
1A) Removal of the Throttle Body (Difficulty: 1)
The throttle body, which is the unit that controls the inlet of air into the engine, must be removed first. This is accomplished by loosening the (3) 10mm bolts with a socket wrench, that connected it to the intake manifold cover. After these three bolts are removed the throttle body we removed by hand, as shown in Figure 1. It is very helpful to put all bolts in separate plastic bags to keep them organized. These bolts would be labeled "Throttle Body Main Bolts" on the plastic bag. This step is relatively simple due to the fact that only three bolts need to be removed for the throttle body to be removed. The throttle body is intended to be taken off because it usually must be removed for any internal engine, or cylinder head work. Further more, the use of non permanent fasteners (bolts) show that it was intended to be removed. However it does have a gasket to make an air tight seal with the intake manifold cover and therefore should likely be replaced if it is removed. The throttle body, consisting mainly of a large piece of metal, can be broken down into a few pieces due to its moving throttle plate and spring.
1B) Removal of Intake Manifold Cover (Difficulty: 3)
The next step is the dissection of the upper intake manifold system. This entire system includes the intake manifold cover, engine control unit, fuel injection system, as well as the individual fuel injectors. This is first done by removing the (10) 10mm bolts that connect the cover to the intake manifold itself, however our engine was missing (4) of these bolts. This can either be accomplished by using a 3/8 inch drive socket wrench or a simple 10 mm wrench. Place these bolts in a bag named "Intake Manifold Cover Bolts". Next the fuel injectors can be removed from the fuel inlet passages on the intake manifold. This is accomplished by squeezing the black pinch connectors then pulling each injector out of its passage. This step of the process is more complex and time consuming than the previous due to both the number of bolts as well as the connectors of the fuel injectors. However our group ran into no major challenges when removing these parts. The intake manifold cover is intended to be removed in order to service the fuel injectors, which are also intended to be removed. This is evident by there open and non permanent connection to the intake manifold as well as most fuel injectors typically need multiple services throughout an engine's life.
1C) Removal of Distributor (Difficulty: 1)
The distributor, which communicates to the spark plugs when to ignite, is the next step in the dissection process. This is done by removing the one 10 mm bolt that holds the distributor to the engine block. This must be done using a 10 mm wrench because the distributor would block a socket wrench from reaching the bolt. After this bolt is removed the distributor may be removed by hand. Again place this bolt in a bag named "Distributor Bolt" and keep with the distributor. This step is simple, and not time consuming at all because it only involves the removal of one bolt. Our group ran into no challenges removing this part. It is intended to be removed, having a non permanent fastener, however there is a very complicated procedure to re-installing this. The gear at the bottom of the distributor rotates with the camshaft, and must be in a exact place to function correctly because this tells the spark plugs when to fire to what cylinder. Therefore if the distributor is off by even a few threads of the gear, it will not fire the correct cylinder and the engine will not function.
1D) Disconnection of Fuel Injection Sub-System (Difficulty: unknown)
The fuel injection system, the black box with lines connecting to the individual fuel injectors, is the next step of the process. There is one 8mm Allen bolt that must be loosened from the intake manifold in order to removed the entire system. Our group could not reach this bolt because a shaved head Allen wrench, or a compact Allen wrench must be used due to the lack of vertical space between the bolt and the fuel injection controller. We had an 8 mm Allen wrench, but were not able to modify it to work in this application therefore the fuel injection system was left on the intake manifold. This part is clearly intended for dissection due to the bolt and the fact that entire fuel injection systems need service regularly.
1E) Removal of Intake Manifold (Difficulty: 2)
In the final step of the removal of the air intake system, the intake manifold must be removed. This is the part that actively directs the air to each individual cylinder and allows for the injection of fuel through the intake ports. To remove the intake manifold from the engine you must loosen the (8) 13 mm bolts holding it to the engine block. This can be done via a 3/8 inch drive socket wrench for proper torque. After the bolts are removed the intake manifold assembly, with or without fuel injection system connected, may be physically lifted from the engine block. This step is simple, but the intake manifold is heavy and includes 8 bolts to loosen, therefore it received a difficulty rating of 2. This part is designed to be removed from the engine, however not designed to be disassembled itself. This is because it is a solid piece of metal, in our case aluminum, and have virtually no parts in it besides the fuel injection system if left connected. The water outlet and coolant sensor are still connected to the intake manifold however these pieces will be discussed in Step 3.
Connection to Engine
The air intake system connects directly to the valve train through the intake manifold. This connection provides a physical path for mass to flow through, from the engine bay to inside the cylinder. As an engine proceeds through its cycle, air must be introduced into the combustion chamber. This is controlled by the valves. There are two per cylinder; one for air intake and one to remove exhaust gases. Air is sucked through the intake piping due to a vacuum created by the piston. It then travels to the intake manifold, which separates the one flow of air into six different parts, one for each cylinder. Once a valve opens, the vacuum causes the air to flow into the cylinder. These two systems must be connected in order for the engine to function, without air in the combustion chamber, an explosion would not occur, resulting in no power being produced by the engine.
The size in the intake piping and amount if air being placed in the cylinder are effected by societal, economic, and environmental concerns. A consumer's desire for a more powerful engine or a more fuel efficient engine could be fulfilled by altering the amount of air in the cylinder. A fuel efficient engine would create less emissions and cost less to run concerning fuel. Th air intake must come before the valve train or air would not be able to enter the cylinder, rendering the engine useless.
Step 2: Removal of Valve Train System
2A) Removal of Valve Cover(s) (Difficulty: 1)
The valve covers, the black plastic pieces which encase the top of the cylinder head, must be removed first in order to get to the cylinder head. The valve covers have (3) 13 mm bolts connecting them to the cylinder head, loosen these bolts with a 3/8 inch drive socket wrench. Our group only removed one valve cover because we were sharing the engine for disassembly therefore left half of the engine, one cylinder bank, untouched. However both valve covers are removed in the same manor. Only having three easily accessible bolts to remove makes this step simple and non time consuming. This part was clearly made to be removed due to the openness of the bolts to remove the valve cover, as well as the need to service the cylinder head in high mileage engines.
2B) Disassembly of Rocker Arms (Difficulty: 4)
The rocker arms, which convert the linear motion of the pushrods into the linear motion of the valves in the cylinder head, are to be dissected next. The rocker arms are under spring pressure from the valve springs and therefore should be removed with care as to not shoot a rocker arm bolt or seat across the room. Our group accomplished this by having one group member relieve the valve spring pressure by pushing down the valve with a flat head screw driver, while another group member loosened the 13 mm bolt on top of the rocker arm. This step must be repeated twice per cylinder, or 6 times per cylinder bank (12 for the entire engine). This step is very time consuming due to the number of rocker arms, as well as technically difficult not because of the complexity process, but because of the effort needed. Therefore this step receives a difficulty rating of 4. The rocker arms are intended to be removed and disassembled into the three parts (rocker arm, bolt, and bolt seat) as evident by the non permanent bolt, as well as the need to service the entire cylinder head of higher mileage engines.
2C) Removal of Pushrods (Difficulty: 1)
The pushrods, which are the long metal rods which transmit the camshaft energy to the valves, are the next parts to be removed in the dissection process. After the removal of the rocker arms, the pushrods are free to be removed by hand from the top of the cylinder head, remove all 6 per cylinder bank. This can be done by hand or if slippery by vice grips. This step is relatively very simple, non time consuming, and does not require any tools. The pushrods were intended to be removed in order to remove the camshaft, however being a solid piece of metal, they cannot be dissected any further.
2D) Removal of Exhaust Manifold (Difficulty: 3)
The exhaust manifold is the metal piece which collects the exhaust gases from each cylinder and dispose of the gases into the rest of the exhaust system. There are two exhaust manifolds, one per cylinder bank, and each manifold is connected by (6) 14mm bolts. Loosen these bolts while having a group member support the exhaust manifold because it is rather heavy. The manifold can then be removed by hand from the cylinder head. Our group ran into a small challenge of removing the exhaust manifold from the cylinder head due to rust, however with a slight force this was accomplished easily. Due to the weight of the exhaust manifold and the number of bolts that needed to be removed this step receives a difficulty rating of 3. The exhaust manifold is designed to be removed, shown by the non permanent fasteners (bolts), but is supposed to have a gasket between the manifold and the cylinder head, ours did not. This gasket would be necessary when re-assembled.
2E) Removal of Cylinder Head (Difficulty: 3)
The removal of the cylinder head is the final step in removing the valve train system. We accomplished this by loosening the (7) 13 mm bolts with a 3/8 inch drive socket wrench, while supporting the cylinder head itself. These bolts are also called head bolts, and after there removal the entire cylinder head may be removed by hand carefully due to its weight. The outer most two head bolts must be labels due to their shorter length, and must be reassembled in their exact location. Due to the heavy weight of the cylinder head, and the number of bolts that we removed, this step received a difficulty rating of 3. The cylinder head was designed for removal as well as further dissection than our group was able to achieve. This is because our group was unable to locate a valve spring compressor, a tool needed in order to dissect the cylinder head. The cylinder head contains the valves, two in each cylinder (6 per bank), valve seals, valve seats, valve springs and valve retainers. All of these parts are not able to be further disassembled but are common to replace and service in older engines.
Connection to Engine
The valve train is indirectly controlled by the rotation of the crankshaft. The crankshaft has a gear and one end that is connected to a gear on the end of the camshaft by a metal chain. The camshaft is comprised of twelve lobes, which, as they rotate, force the pushrods up. The pushrods are connected to the rocker arms, which act as levers, to force a valve to open, which are spring loaded in e closed position. The camshaft converts the rotational energy of the crankshaft into linear movement of each valve. Without this connection, the valves would not open and air and fuel would not be introduced into the combustion chamber. The systmes are connected both physically and by energy.
The amount each valve moves linearly is taken into consideration when designing an engine. This distance is effected by environmental as well as social concerns. The size of each lobe are effected by societal, economic, and environmental concerns as well. A consumer's desire for a more powerful or more fuel efficient engine could be fulfilled by altering the amount of air in the cylinder. A fuel efficient engine would create less emissions and cost less to run concerning fuel costs. The valve train must come before the combustion chamber so the cylinder has the air and fuel available to combust, and also has many factors contributing to its design. Having to be in motion the majority of the time, the pushrods and rocker arms shown are have the economical design factors of being mass produced to save on production costs while also having environmental design factors contributing to their light weight.
Step 3: Dissection of Cooling System
3A) Removal of Water Pump (Difficulty: 2)
The water pump is an essential part of the engines cooling system which circulates cooled water through the engine to keep the temperature within certain limits. In order to remove the water pump from the front of the engine block we loosened the (4) 14 mm bolts holding it in place. While supporting the water pump, loosening the last bolt, and then the water pump was easily removed from the engine. Although the water pump must be supported, it is not substantially heavy and there are only 4 bolts needed to remove it therefore we gave it a difficulty rating of 2. The water pump is intended to be removed from the engine, evident by the four non permanent fasteners securing it to the engine block, as well as the bolts holding the pulley to the water pump. However the water pump is not design to be disassembled, if it fails, which is common, they are simply meant to be replaced. Although some manufactures rebuild broken water pumps, it is a complex task and is not design for easy dissection due to the casting and permanent connections within the water pump.
3B) Dissection of Thermostat (Difficulty: 1)
The mechanical thermostat is located inside of the intake manifold, and controls the flow of coolant to either keep it inside of the engine or cycle it through the radiator to cool it. We disassembled it by first removing the radiator outlet pipe, by loosening the (2) 10 mm bolts holding it to the intake manifold. After removing the radiator outlet pipe, we removed the mechanical thermostat with a flat head screw driver, leveraging it out of the intake manifold. This is a relatively simple task, requiring minimal effort and only 2 bolts, therefore we rated this step at a difficulty of 1. The thermostat itself is intended to be removed from the engine because over time it begins to not function as intended. Being spring operated sometimes the spring can loose tension over time and must be replaced. However the thermostat was not intended to be dissected as evident by the permanent connection of the spring, upper and lower seats, and the valve. Therefore our group did not attempt to dissect the thermostat.
3C) Removal of Electric Water Sensor (Difficulty:1)
Next to the mechanical thermostat housing is an electric water sensor. We removed this by loosening the (2) 10mm bolts holding it to the intake manifold. However our group does not know exactly what this sensor does, but the removal was simple and non time consuming so this step received a difficulty rating of 1. The unit is obviously a sensor because it have an female electric sensor connection on top of it, and also has two holes on the intake manifold side, we presume to inlet and outlet water for some sort of data capture. This was also one unresolved challenge of our group, figuring what type of sensor this was. The sensor is designed to be removed from the engine, as shown by the open, non permanent bolts securing it. However it is clearly not meant to be dissected due to the permanent connections inside of it and holding it together. Portraying the fact that if the sensor fails it is common to simply replace it.
Connection to Engine
The water pump is controlled by the rotation of the crankshaft, but not directly. The crankshaft is connected to a belt on one end which is connected to a few different components, including the water pump. The water pump is connected to the radiator and the engine block. It converts the rotational energy of the crankshaft into flow energy of coolant fluid. Is fluid is pushed through the engine block and heats up until it reaches the radiator. While in the radiator, air is passed by to cool the fluid. It is then pumped through the block again in a full cycle. Without this connection, the water pump would have to be powered another way, possibly electrically. If not connected at all, the engine would quickly overheat and cease to run. The size and power of the engine determine the amount of heat produced. The more heat an engine produces, the large the water pump must be in order to cool the engine to an acceptable temperature. This process constantly occurs while all the other subsystems are running.
Step 4: Disassembly of Timing System
4A) Removal of Timing Chain Cover (Difficulty: 2)
With the water pump removed from Step 2, the timing chain cover can than be accessed. Our group performed the entire removal of the timing system in a very unconventional way. Due to our limited tools, we were not able to obtain a pulley puller, which would be needed in pulling the crankshaft pulley off, which would then give complete access to the timing chain cover and assembly. This was one of our major challenges our group faced, needing to get to the timing system and also in order to get the rotating assembly out. Not wanting to damage the crankshaft, or crankshaft pulley in any way by using a mallet to free the pulley from the crankshaft, we decided to take a different dissection route. We first removed the outer crankshaft belt pulley by loosening (3) 13 mm bolts and simply removing the belt pulley, however one of our bolts was missing. Next with the crankshaft main pulley exposed but still in place, we went about loosening the timing chain cover bolts, (8) 10 mm bolts around the edge of the cover with a 3/8 inch drive socket wrench. With the timing cover bolts removed, we were able to pull the timing chain cover out about an inch and a half, resting on the crankshaft main pulley. We then proceeded on with the timing chain cover still attached between the crankshaft and the crankshaft pulley. This step of the process is rather simple, however it is time consuming with the number of bolts that must be removed, therefore we rated this step as a difficulty of 2. The timing chain cover is intended to be removed, as evident by the gasket between it and the engine block, as well as the non permanent fasteners that secure it. Also the timing chain cover even states on it to replace with a new one after removed, this is in order to keep a good seal in between it and the engine block so no oil leaks from here.
4B) Unseating of Timing Chain (Difficulty: 5)
With the timing chain cover out, we were then able to use a flat head crew driver to pull the timing chain over the camshaft gear. This is a simple step however requires a good amount of technical skill to be able to unseat the timing chain from the gear guides, while also holding the timing chain cover away from the gear. This simple step took our group approximately half of an hour to unseat the timing chain, being very careful not to break any teeth of the camshaft gears, or links of the timing chain. For the reason of time consumption, this step is rated at a difficulty of 5, and also for the technical skill needed to successfully achieve this task. The timing chain is designed to be removed, however first through the removal of the crankshaft pulley. Timing chains are commonly replaced when overhauling the old or broken internals of an engine, and have non permanent connections to do so.
4C) Removal of Crankshaft (skip to step 5A-5G)
4D) Removal of Timing Gears (Difficulty: 2)
Once the crankshaft is removed from step 5, the entire timing assembly is visible and can now be removed. The primary camshaft gear is the large must outer gear, we removed this by loosening the (3) 14 mm bolts while supporting the camshaft gear to make sure it did not spin. However our group's engine only had two of the three camshaft gear bolts, but once they are removed the gear was easily removed by hand. After this gear is removed the secondary camshaft gear or camshaft sprocket. This is again done by removing the (3) 14 mm bolts that hold the camshaft sprocket into place, and then we were easily able to remove the sprocket by hand. This step is relatively easy having only basic bolts to remove and our group gave this step a difficulty rating of 2. The timing gears themselves cannot be disassembled any further being solid pieces of metal, however they can be easily removed having non permanent connections to the camshaft and balance shaft. Our group did not further disassemble the balance shaft gears because we did not feel this would be beneficial to any disassembly due to their exposure and lack of importance.
4F) Removal of Camshaft (Difficulty: 1)
After the timing gears have been removed, the camshaft is then able to be taken out. We removed the (2) T30 bolts holding the camshaft housing to the engine block, then the camshaft seal was removed by hand. After this step the camshaft was then removed by pulling from the outside of the engine block and supporting it while pushing from the inside. This step is rather simple due to the number of open bolts needed to be removed and was therefore given a difficulty rating of 1. The camshaft itself is designed to be removed, as shown by the use of non permanent connections to the engine block. However the camshaft is a solid piece of metal and therefore cannot be disassembled any further, and when damaged or over worn from use, it is typically replaced rather than serviced.
Connection to Engine
The timing system connects the crankshaft to the camshaft by a heavy metal chain. The crankshaft has a gear on one end, called the timing gear, which is connected to the timing chain. The camshaft has a gear on one end which is also connected to the timing chain. Th timing system allows the rotational energy of the crankshaft to turn the camshaft as well. The size if each gear is extremely important as the two shafts can not spin independently. The function of each depends directly on the action of the other. Since the camshaft controls the valves, it must spin at the correct rate in order for the valves to open and close at the correct time. If the intake valve opens too late, the cylinder will not have enough air to combust properly. If the exhaust valve opens early, there will be nothing in the cylinder to explode. Both cases result in the engine producing little to no power.
Step 5: Dissection of the Rotating Assembly
5A) Removal of External Oiling System (Difficulty: 2)
In this stage of the dissection process, it was very beneficial to our group to rotate the engine stand 180 degrees so the oil pan is on top. The first step in the dissection of the rotating assembly was the removal of the external oiling system. We believe that this piece is an oil inlet/outlet to either an external oil filter housing, or to an oil cooler device. Neither of these items however were included with our engine. To remove this oil inlet/outlet device our group loosened the (2) 10mm bolts holding it in place, then pulled it out by hand. Having only two simple bolts to remove, but also having to rotate the engine stand which takes a good amount of force, this step is rated at a difficulty level of 2. The oil inlet/outlet is designed to be removed, evident by the non permanent connections between it and the engine block, however it is not intended to be disassembled. This is because it is clearly made from one whole piece of aluminum and any disassembly would require destruction of the piece.
5B) Removal of Oil Pan (Difficulty: 3)
The oil pan is the part that holds oil for the engine while not functioning, as well as where oil is collected and recirculated while the engine is functioning. To remove this part our group loosened the (10) 13 mm bolts holding the oil pan in place around the outside of the assembly, however there were only 6 bolts to be found. After this the oil pan was successfully removed by pulling directly up on the part. Due to the slightly heavy weight of the oil pan, as well as the number of bolts affixing it to the engine block, this step recieved a difficulty rating of a 3. The oil pan was designed to be removed, as again evident by the non permanent connections and also shown by the fact that any service to the internal parts of the engine would require this part to not be there.
5C) Removal of Internal Oiling System (Difficulty: 1)
The next step in the dissection process is the removal of the internal oiling system. The internal oiling system consists of the oil pickup and oil pump, was removed by loosening the (2) 16 mm bolts holding it to the bottom of the engine block. It was then removed by hand, and due to the simplicity of this step, received a difficulty rating of 1. This part was both intended to be removed, and intended to be disassembled. This is shown by the non permanent connection of the assembly to the engine block, and also the non permanent connection (bolts) of the oil pickup to the oil pump. These are both common failures on higher mileage engines, and therefore easily replaceable and even serviceable.
5D) Removal of Connecting Rod End Caps and Rod Bearings (Difficulty: 3)
The connecting rods are what connect the piston to the crankshaft, and are the main translators of linear into rotational energy. The connecting rod end caps are what hold the connecting rods to the crankshaft. To remove the end caps there are (12) total 14 mm nuts, two on each end cap, that must be loosened. After the two nuts on a end cap are loosened, we removed the end caps with a flat head screw driver, prying the end cap away from the crankshaft. The bearings may then be removed by hand, and this process repeated for each end cap, however our group only did 3 end caps having to share the engine with another group. We gave this step a difficulty rating of 3 because although it does consume a good amount of time, it is relatively very simple. Our group ran into the problem of not being able to reach all of the end cap nuts, therefore we needed to use a six inch extension on the socket wrench. These parts are meant to be removed because that is the only way to remove a piston however they are not meant to be further disassembled being a solid piece of metal.
5E) Removal of Main Bearing Caps and Main Bearings (Difficulty: 2)
The main bearing caps are what hold the crankshaft to the engine block and contribute to the transformation of linear into rotational energy. Our group removed these be loosening the (8) 14 mm bolts holding the main caps to the engine block. After these bolts are loosened and removed, the caps were taken out by hand, along with the main bearings. This is a very simple step and was given a difficulty rating of 2 due to the number of bolts removed. The main bearing caps are meant to be removed for a number of reasons, and shown by there non permanent connection to the engine block. They are commonly removed in order to service the internals of the engine, as well as the bearings themselves, which often become to worn or spun in their seats, needing to be replaced.
5F) Removal of Crankshaft (Difficulty: 2)
The crankshaft is what translates the rotational energy of the engine out of the motor, is removed next in the process. To removed this, our group simply had one person on each end of the engine, and lifted up on both sides of the crankshaft, pulling it up and out of the engine. No tools were needed in this step of the process because all necessary bolts were previously removed. Therefore this step received a difficulty rating of 2 simply for the weight of the part. The crankshaft was designed to be removed from the engine, shown by the non permanent connections (bearings) to the engine block, however being a solid piece of metal was not designed to be disassembled any further.
5G) Removal of Pistons and Connecting Rods (Difficulty: 2)
After the crankshaft is removed the connecting rods and pistons are then able to me removed. By pushing down on the connecting rods by hand, while having another group member at the cylinder to catch the piston and rod, the two are easily removed from the cylinder. This process is repeated 6 times for the total engine, however our group only did it three times. Again no tools were used in this step however a flat head screwdriver of rubber mallet may be used if the piston will not move easily. Our group again rated this step at a difficulty level of 2 due to its simple procedure, lack of tool usage, yet it can take some time. The piston and connecting rod are designed to be removed, as evident by there non permanent connection to the crankshaft, and they are also designed to be disassembled even further. The connecting rod may be removed from the piston by removing the pin connectors inside the piston, and the bearing on the pistons. Also both the compression and oil piston rings may be removed from the piston may hand.
Connection to Engine
When the oil pan was removed, the oil pump and pick up was exposed. The oil pump, like the other accessories, is driven by the crankshaft. The crankshaft turns a set of gears when connects to the oil pump. The pump uses that rotational energy to circulate oil around the engine. This lubricates and cools the many moving parts inside the motor. Without this connection, the friction inside the engine would become too high to the point of failure. The global concerns effect the size of the oil pan and oil pump depending on intended use. The engine may be used for only commuting, but it may also be used for hauling or towing. The components must be able to handle all types of usage.
Connection of Subsystems
The GM Vortec 4300 has numerous subsystems that are an integral part of the engines ability to function. All the subsystems relate to the crankshaft in some way and have to be physically connected. They either use the rotational energy or convert it to linear to complete their intended jobs. An engine has to have near perfect timing to function properly for a long period of time since all of these subsystems depend on each others' actions. Since it is a cycle, each function depends on an action before it or directly after it. One failed connection can devastate this cycle and possibly destroy the engine.
During this dis-assembly we were able to work as a group to take apart our V-6 engine. We were able to see the internal components of the engine and observe how each part worked with one another in harmony so that our engine could function successfully. While going through our dissection, we would occasionally run into some minor problems. Most challenges were able to be fixed without a problem but some remained unresolved. Never the less, we were able to finish our dissection successfully and understand the inner workings of the engines subsystems and all of its components. We will now move on to Gate 3 which deals with the Product Analysis.
Dissection Photo Library
Dissection Photo Library - Assortment of photos taken during dissection.
Thanks to Photobucket©
Gate 3: Product Analysis
Project Management: Coordination Review
Cause for Corrective Action
As we continue to advance in the project, our group maintains successful work ethics and teamwork as we communicate amongst one another with any questions, concerns or suggestions we might have. In completing this gate we came across a few challenges that were, for the most part, resolved while analyzing our engine in greater detail.
The first challenge we faced was not having the proper tools in the laboratory to determine precisely how large our individual components were. We were seeking the weight of such components like our intake manifold cover and piston, as well as the dimensions of the intake manifold cover and connecting rod. To complete this task we had to use the resources available to us as well as the method of estimation. There was a small ruler in the lab that we were able to get some of the dimensions from while with others we had to use an approximated guess. For instance with the intake manifold cover we were able to eye ball the dimensions based off of prior knowledge and experience such as knowing a piece of paper is usually 8.5 inches by 11 inches long so we compared the lengths of a piece of loose leaf paper to the length, width and height of the cover. Same as for the weight, we know how heavy for instance a textbook is so we approximated the weight of our components that way.
A second challenge in this gate was locating the model/part numbers of each component. This posed to be an issue because most of our parts seemed to be "fit", which means they are exact in measurements to the engine in which they belong, and due to the wear of our engine and its components, no serial numbers could be seen. This challenge is considered to be resolved as well as unresolved; part numbers were found based off the type of engine we have and matched up with similar physical characteristics but no definite part used in the Vortec 4300 was found.
Shape description of the components came off as a minor challenge to us. To clearly and effectively illustrate the appearance of the components took some creative thinking on our part. We resolved this by referencing other common shapes and adding adjectives to them to create the best visual for the reader. For instance we described the shape of the rocker arm as an elongated bell shape.
During gate 2 one of our unresolved challenges dealt with the further examination of the valve train. This remains an unresolved challenge due to time constraint and being unable to access a valve compressor.
The last and what seemed to be a major challenge in this gate was creating our solid model using CAD. The issue with this was not having full access to the computers on campus that we were told had the solid modeling programs needed to complete this task. After continually logging-in to numerous computers we were still unable to access these programs. This lead us to have to download inventor from the Autodesk website onto one of our personal laptops in order to complete this section of the gate.
Again we as a group used teamwork and prior knowledge and skills to resolve the challenges we encountered. We worked together to find a reasonable solution we could all agree upon to complete the tasks at hand.
The Timing system of an engine is made primarily of two parts, the timing chain and timing gear.
The main function of the timing chain is to connect the cam gear to the timing gear so that they rotate with one another. The timing gear then works with the timing chain to rotate the camshaft according to the crankshaft in order for the car to perform well. The energy flows that these two parts have are both mechanical energy while the timing gear also has rotational energy. The timing chain works in an environment with variable pressures while the timing gear is exposed to the outside of the engine and encased in oil.
The timing chain has a very simple shape to it. It is comprised of several symmetrical chains linked together to form a large circular chain. While the timing gear is a circle with teeth on the edge giving it radial symmetry. The timing chain and timing gear's forms relate to its function in the way that it needs to be able to wrap around the two gears while the timing gear needs to be circular in order to deliver rotational energy. Some other characteristics are:
|Timing Chain||Timing (Cam) Gear|
|Dimensional||2 dimensional||2 dimensional|
|Size||2 feet long||5 inch diameter and ½ inch thickness|
|Weight||2 pounds||1 pound|
|Aesthetics||Unpainted flat metal finish||Unpainted steel, flat metal finish|
The methods to which these two pieces were made are very different. The timing chain was made with forging. This is because the steel pieces are too small to make by die cast so must be forged with metal. The choice of material did not have any impact on the process of manufacturing used but the process was used because the single pieces of steel are very small. The timing gear on the other hand was die cast. This is because of its simple shape and using this process would be the easiest way to manufacture this piece. There was also no impact on the choice of manufacturing technique based on the material used or the shape.
Both the timing chain and timing gear are not very complex pieces to make. The timing chain pieces may be slightly harder to manufacture and assemble than the timing gear but that is just because the timing gear is one solid piece. Using a scale from 1 - 10, 10 being the hardest to manufacture, the timing chain is about a 5 and the timing gear is around a 3. And the complexity of interactions with other parts of the engine are not very complex as well.
Valves are very important to how a engine runs. Without the valves, the gas and fuel would not be able to enter the cylinders making the engine useless.
The main function of the valves are to intake fuel and air and expel the exhaust gases which come from the combustion of the mixture. The valves undergo mass flow energy which is made of air, fuel and exhaust gases. Also, the environment in which the valves work in are variable pressures and high temperatures.
The general shape of a valve is an elongated bell which happens to be symmetrical about one axis. The shape of the valve allows for a complete air-tight seal to the combustion chamber which helps it undergo its function to the engine. Other notable features of its shape are:
|Size||1.5in diameter and is 5in long|
|Aesthetics||Unpainted aluminum with a smooth surface finish to reduce friction and seal combustion chamber more efficiently|
A method for manufacturing valves is called turning. The reason for this process is because of the valve's axial symmetry. The shape has a high impact on the whole process but the material used does not.
The overall complexity of the process of manufacturing of valves is not very high at all because of the simple shape and size. On a scale from 1- 10, 10 being the most difficult, it would be a 1. Because of the shape and material, it is very simple to create this product. The interactions of the valves in relation to other parts of the engine are not very complex at all.
The rotational assembly creates power for the engine to run the vehicle. Some pieces of the rotational assembly are the oil pan and pump, the pistons and connecting rods. These parts play a major role in the functionality of the engine. Without the pistons and connecting rods, linear energy would not be produced and without the oil pan and pump, the pistons would not work properly.
The oil pan and oil pump work with eachother to do one task. They both work to lubricate the camshaft and other parts inside of the engine. The pump moves the oil around while the pan holds it in place. They both have mass energy flow consisting of the oil that they have to work with and the enviroment in which they work is underneath the engine exposed to high temperatures. Like the oil pan and pump, the pistons and connecting rods also work with each other hand in hand. The connecting rod connects the crankshaft to the piston while the piston converts pneumatic energy to translational linear energy. It also changes the pressure in the cylinder to allow the auto cycle to function correctly. The connecting rod has energy flows that deal with mechanical and linear energies while the piston has energy flows that deal with heat, pneumatic and linear along with mass energy flow that deals with air, fuel and exhaust gases. They are also both in similar environments of high temperatures, constant movement and variable pressures.
The general shape of the oil pan is like a square on top of a rectangle, making it symmetrical in the front, while the pump is a very abstract shape that is hard to describe. The shapes of these parts have be this way so that they can fit underneath the engine while not interfering with any moving parts and other functions. The connecting rods have a shape of a symmetrical two pronged fork while the piston is a short cylinder that is perfectly circular, giving it radial symmetry, with two small inpression on the top of it to let room for the valves to open correctly. Other specifications are as follows:
|Oil Pan/ Oil Pump||Connecting Rods||Piston|
|Dimensional||3 dimensional||2 dimensional||2 dimensional|
|Size||1.5 ft X 1 ft X 1 ft||6 inches long and ½ inch thick, 1 inch at skinniest point and 4 inches at its widest point||Radius of 5.5cm and a height of 7.5cm|
|Weight||5 pounds (altogether)||1 pound||About 5 pounds|
|Aesthetics||Unpainted metal, silver because it is on the bottom of the engine where it is not visible||Unpainted steel because cannot be seen||Silver, unpainted with a poor finish from casting|
Becasue of the simplicity of the oil pan, it was manufactured by the process of being die cast but because of the abstract shape of the oil pump, this piece had to be machined. the material of both pieces did not impact the technique used. Like the oil pan, the connecting rods were also die cast because of the simple shape of them and had no impact from the material chosen. The piston was made by casting as well as machining. This is becasue the sides and top of the piston must be as smooth as possible to create as little friction as possible but the bottom of it was rough because it did not come into contact with anything. The shape had no impact on the process used but the material did. The pistons were made of aluminum because of its high resistance to heat.
The oil pan and oil pump have different shapes but they both share the same purpose which is to lubricate the inside of the engine but this process is not too complex. From a scale from 1 - 10, 10 being the most difficult, it is close to a 3. The above categories do not have an affect on the complexity and compared to other systems, the complexity of interactions is simple. THe connecting rods are also fairly simple with a difficulty rating of 2 from the same scale. The previous categories and the complexity of interactions are also very low. The pistons are alittle more complex than the previous items but not by much. This is because the surface finish must be very smooth. Using the previous scale the pisont have a complexity of about 6. The previous categories impact the complexity because the pistons must be made of good, strong metal and must be manufactured well because of the amount of friction applied to the product. But the interactions with others parts of the engine are not complex.
The cooling system plays a very important role in the engine. Without it, the engine would eventually over heat and shut down. There are three main parts to this system, they are the water pump, thermostat and the electric water sensor.
The function of the water pump is that it circulates the water/coolant throughout the engine and the radiator, keeping the engine from overheating. The thermostat is able to bring and maintain the engine up to optimum operating temperature. And the water sensor measures the engine coolant temp and responds to change in ECT by way of the ECM (engine control module)
All three pieces of this systems have very abstract shapes with no particular symmetry or specific geometry but they all are three dimensional with varying sizes. The shapes have to do with the function in the way that they can be abstract shapes and sit on the outside of the engine so they are not limited by any major restrictions. The water pump is made of iron and brass while the thermostat is made of stainless steel or iron and the water sensor has a brass housing. They do not have any aesthietic properties but they are given a clean finish becasue they are placed on the exterior of the engine making it visible to people when the hood is opened which is for aesthetic reasons.
They also used the same technique for manufacturing which is die cast and/or injection molding but the water pump also underwent some machining. This is becasue of the simplicity of the product and the shape. Also, the material did not play a huge role in the choice of material used for the products.
The complexity of each piece is not very high so therefore from a scale of 1- 10, 10 being the most complex, the pieces all together have a complexity of about 3. The three categories above do not play a big role in the complexity of these products being that they are fairly simple to manufacture. On the other hand the interactions are slightly more complex because of the important role that the cooling system has in the engine but all in all, it is still fairly simple.
Solid Model Assembly
Autodesk Inventor was used to model the valve train of the engine. This program was used since Matt is familiar with this software from previous use. The valve, spring, washer, rocker arm, push rod, and lifter were chosen due to their close positioning in the engine and their importance to the overall function. Each part is shown separately below along with an assembly and a link to a video. A link to a .zip file of the CAD models is also shown below.
The main function of an engine, which is to produce usable power that a vehicle can use to move, is what all of the engine's sub functions and components support. An engineering analysis can be applied to any sub system of the engine, but more globally, can be applied to the entire engine itself. This type of analysis would be to determine important overall specifications of the engine before the engine was going to actually be manufactured. Some of these important engine specifications would be power and mean effective pressure.
The problem statement associated with this type of analysis would vary depending on what the engineer wanted to test. In this particular example, we will be establishing the power developed by a certain brake mean effective pressure of the cylinder. Thus the problem statement would display that while saying the mean effective pressure being tested, and for this example we will use a b.m.e.p. of 150 psi. This is a high brake mean effective pressure, which can be used in this engine due to the high strength of the block and pistons.
The assumptions of the analysis can vary extremely depending on what variables an engineer is attempting to test. In this analysis we are testing a particular brake mean effective pressure, therefore it will be an assumption. Conversion factors that will be used in the analysis are also very important. In this analysis our assumptions are:
- Brake Mean Effective Pressure = 150 psi
- 1 hp = .7457 kW
- Swept Volume = Engine displacement = 4300cc = .0043 cubic meters
- Maximum RPM = 55000 rpm
- Assume Four Stoke Engine
- 1 bar = 14.5 psi
For this section of the analysis there is only really only one equation, the equation for power of an engine. However the conversion into horsepower and conversion of b.m.e.p. into bar is also important.
- 1 bar = 14.5 psi
- 1 hp = .7457 kW
- Power Output = 50 X b.m.e.p. (bar) X Swept Volume (cubic meters) X Revolutions per Second (rps) X Cycles per Rotation
- 1 bar = 14.5 psi
- (150psi)(1bar/14.5psi)= 10.35 bar
- Power Output = 50 X b.m.e.p. (bar) X Swept Volume (cubic meters) X Revolutions per Second (rps) X Cycles per Rotation
- Power Output = 50 X (10.35 bar) X (.0043 cubic meters) X (5500rpm/60s) X (2 cycles)
- Power Output = 407.9 kW
- Power Output = 547 hp
Here we will use what is called a unit check, in order to check to ensure the units of the equation work.
- Power Output = 50 X b.m.e.p. (psi) X Swept Volume (cubic meters) X Revolutions per Second (rps) X Cycles per Rotation
- Power Output = (psi)(cubic meters)(rps)(Cycles per Rotation)
- Power Output = (bar)(cubic meters)(rps)(Cycles per Rotation)
- Power Output = (N)(square meters)/(s)(s)(s)
N-m/s^3 = J/s = Watts
As shown, you can see the units in the equation equal joules and therefore the equation checks
After the calculations have been obtained it from the analysis, we must say what these results mean. In our case it is important to emphasize the fact that with a brake mean effective pressure of 150 psi, our engine achieves a power of 445 hp. This answer is obviously not the power output the engine currently achieves, but what it could achieve with the given brake mean effective pressure.
The General Motors Vortec 4300, while engineered at a high level of excellence at it's time of development, can be majorly improved due to the increases in current technology. These design revisions can also be made while keeping constant the intended use of the engine, as well as the target price point relative to the time it was produced.
The engine block of the Vortec 4300 is made of cast iron, a very heavy and inexpensive metal. At the time of production the use of cast iron from the engine block was feasible due to its relative high strength, low cost, and low production cost. However with current technology, an aluminum engine block is much more feasible. The use of an aluminum engine block can reduce the weight by almost 50% compared to its' cast iron equivalent. This dramatic decrease in weight positively affects the fuel consumption of the car, making it far more environmentally friendly. Decreased vehicle weight also increases societies view of the car, making the vehicle more fun to drive, increasing consumer satisfaction. The use of an aluminum engine block also allows the actual block to have a far greater resistance to rust and other environmentally degrading factors. Lastly the costs of aluminum have decreased since the design of this engine, therefore the actual material cost of the engine would increase only slightly, having almost no negative impact on economic design factors. For these reasons it would be beneficial to revise the design of the engine block to have it cast of aluminum.
Along with the material of the engine block, many of the materials of the Vortec 4300 can be changed to improve the design of the overall engine. However the most important being the rotating assembly of the engine, being the main component of the engine that provides the main function of the engine. At the time of the design of the Vortec 4300, engine displacement was a major consideration, instead of rotational efficiency or mechanical efficiency. Therefore although the engine displaces a relatively large amount compared to most six cylinder engines, it seriously lacks in refinement and efficiency of power. This can be revised by changing the rotating assembly sub system, changing the material to a light weight alloy which if forged, not cast iron. This change greatly reduces the rotating mass of the assembly, therefore causing less frictional losses and creating more power by the engine while also consuming less fuel. This portrays the economical design considerations with using a lighter weight material for the rotating assembly, while also improving societies perception of the engine. While this material change would be relatively more expensive than would be considered in the exact same price point, the increase in performance, efficiency, and reliability would be factored into the engine's overall design considerations.
The Vortec 4300 utilizes a mechanical water pump to circulate the coolant through the engines cooling system. This means that it is belt driven by the rotational energy of the crankshaft transferred via a belt to the water pump. At the time of design, this was a feasible and acceptable method of circulating the fluid. However with the technological advancements of today, this method is no longer the most beneficial way to accomplish this task. This mechanical water pump can easily be replaced by an electric water pump for many reasons, the most important of which being the rotational drag on the engine that a mechanical water pump causes. This rotational drag is deleted by an electric water pump because this type of water pump takes energy from the vehicles battery, which is stored there instead of taking from the rotational energy of the crankshaft. This elimination of the water pump drag increases overall engine efficiency, showing its beneficial environmental consideration. The electric water pump revision also illustrates the economical design considerations by saving in overall parts, belts and systems involved with a mechanical water pump. While the Vortec 4300 was very well design from the factory, over time some of the technology has improved allowing for beneficial design revisions to the product.
|Component Name||Quantity Used||Function||Material||Manufacturing Process||Fastener Used|
|Throttle Body||1||Control the flow rate of air into the engine||Aluminum||The throttle body is made of for smaller parts, a spring, the body, a valve, and a trigger that were most likely casted||Three (3) 10mm Bolts|
|Intake Manifold Cover||1||Protect the engine control and unit and fuel injectors||Plastic||Based on the shape and material the cover was most likely casted||Ten (10) 10mm Bolts|
|Distributor||1||Tell the spark plugs when to ignite||Plastic and Steel||Molding for the plastic and steel||One (1) 10mm Bolt|
|Fuel Injection Sub-System||1||Manage injection of fuel into cylinder heads||Plastic||This part is very similar to the cover so it is most likely casted||One (1) 8mm Allen Bolt|
|Intake Manifold||1||Direct air into each cylinder head||Aluminum||This part has visible parting rings which is one of the signs of metal casting||Eight (8) 13mm Bolts|
|Valve Train Cover||2||Protect the valve train system||Plastic||The clean, uniform curves and indents suggest casting||Three (3) 13mm bolts|
|Rocker Arms||12, 6 per cylinder head||Connect the valve springs to the pushrods||Steel||Its shape and material most likely means it was casted||One (1) 13mm bolt each|
|Pushrods||12, 1 per rocker arm||Turn the rotational energy of the cam into linear energy for the valve springs||Steel||It may start from one long rod then machined down into each individual rod||One (1) Rocker Arm|
|Exhaust Manifold||2, one per cylinder head||Direct the exhaust gases away from the engine block||Iron||The clean curves and embossed marks suggest casting or forging||Six (6) 14mm bolts|
|Cylinder Head||2||Manage the intake of fuel and removal of exhaust, house valve springs and the valves||Steel||Clean curves and embossed lettering marks suggest casting or forging||Seven (7) 13mm Bolts|
Gate 4: Product Reassembly
Here is our groups Product Reassembly Difficulty Scale (Chart 1). This illustrates the difficulty of each of the following Reassembly Steps.
|1||Very simple, requires minimal effort and time|
|2||Simple but may require some effort|
|3||Fairly simple but requires some effort and time|
|4||Complex and requires effort and time|
|5||Complex and requires excessive effort and time|
Chart 1: Difficulty Scale
Reassembly of the Rotating Assembly
Pistons and Connecting Rods (Difficulty 4)
After we put the camshaft into place we put the pistons and connecting rods back into its original cylinders to match the boring. To do so we used a piston compressor to compress the pistons and piston rings. Then we took a rubber mallet and pushed the piston into position and undid the piston compressor. It has a difficulty of 4 because it requires a good amount of effort and the use of specialty tools. During actual assembly process this may be done after the crankshaft and main bearing caps is installed and with the rod bearing and connecting rod end caps because with tight piston rings this motion could be easily automated and done rapidly. This step was different from the dis-assembly because we had to use a piston compressor to put the pistons back into place instead of just hitting them back into place.
Crankshaft (Difficulty 3)
To put the crankshaft back into place we had to make sure all the connecting rods were in a position where the crankshaft would not hit it when placed. Next we to crankshaft and put it in its ridges, during which we had to move a few of the connecting rods. After the crank was in place we put the connecting rods tight to the crankshaft for attaching the rod end caps Because of the during-installation moving of other components, installation of the crankshaft has a difficulty of 3. During an assembly proses the crankshaft would most likely be the first component installed on the engine block in a preset position to make the installation of the connecting rods and bearing caps easier. this step was almost the came as the dis-assembly except that we had to position the connecting rods.
Main Bearing Caps and Main Bearings (Difficulty 2)
To install the Main Bearing cap we first had to put the main bearings in place on the cap, and then we put all four of the main bearing caps in place and tightened them down with (8) 14mm bolts. This step is given a difficulty of 2 because it is simplicity and the number of bolts. In the assembly proses this would be done after the crankshaft to help hold in place. This step was just the dis-assembly in reverse.
Removal of Connecting Rod End Caps and Rod Bearings (Difficulty: 2)
After we put the main bearing caps in place we put the rod bearings back into the connecting rod end caps then we put them on each of the connecting rods and tightened the (12) 14mm nuts on to the connecting rod, two on each connecting rod end caps. This step has a difficulty rating of 2 for its simplicity and number of nuts. During a manufacturing proses this would be done after the pistons were installed to hold them in place. Just like the main bearing caps, to do this step we just followed out dis-assembly process in reverse.
Internal Oiling System (Difficulty: 1)
To put the Oiling system back in place all we had to do is put in (2) 16mm bolts to reattach the oil pump to the block, which is why this step has a difficulty of 1. During an assembly proses this would be done after the crankshaft and pistons are in place and are secured. To put this component back on we just followed out dis-assembly instructions backwards.
Oil Pan (Difficulty: 3)
After we put the internal oiling system back in place we put the oil pan over most of the parts of the rotating assembly. This required that we lift the oil pan above the internal oiling system then put (6) of the (10) 13mm bolts we have back in place. This has a difficulty of 3 because of how heavy the oil pan is and the fact you have to lift it up above the internal oiling system. During assemble this was put on after the internal oiling system. We put this component back on by doing out dis-assembly instructions in reverse.
External Oiling System (Difficulty: 2)
Actually putting the external oiling system was easy, simply putting (2) 10mm bolts back into place, but after that we had to rotate the engine 180 degrees to get it back into its original position . The reason the difficulty is a 2 is because it takes quite a bit of force. During assembly this would put on after the oil pan, but it may or may not be turned. This component was also put back on by taking the dis-assembly instructions and doing it in reverse.
The first thing we put back into the engine block was the camshaft which is part of the timing system, then we used a piston ring compressor to get the pistons back into place before we reseeded the crankshaft. After that we put the main bearings and main bearing caps back into place to hold the crankshaft in place then we put all the pistons in place so we could put the rod end caps and rod bearings into place to connect the pistons to the crankshaft. After that we put all the internal oiling system components into place, put the oil pan over that and attached all the external oiling components.
Reassembly of the Timing System
Camshaft (difficulty: 1)
The first component we put back in the engine is the camshaft, we put this back into the engine simply by pushing into the camshaft housing then putting on (2) T30 bolts, which is why this step has a difficulty of 1. During the assembly proses this would be done before the rotating assembly is installed. To put this component back into position we followed the dis-assembly instructions backwards.
Timing Gears (Difficulty: 3)
In order to get the secondary camshaft gear back on we had to line up all three with the holes on the camshaft then put on (3) 14mm bolts, then do the same for the primary camshaft gear then put on (3) mire 14mm bolts. This step has a difficulty of 3 because lining up the holes can be a little hard. During manufacturing this would be done after the camshaft is in installed to hold it in place. This step was similar to the dis-assembly but we had to make sure the holes on the gears lined up with the rods on the end of the camshaft.
Timing Chain (Difficulty: 5)
Reseating the timing chain was one of the hardest steps of the reassembly because we had to get the chain to reseat which was both time consuming and took a lot of effort which is why this step has a difficulty of 5. During an assembly they my seat the chain and install the primary camshaft gear in the same step. This step was just as hard to assemble as it was to disassemble so we simple followed our dis-assembly instructions backwards.
Timing Chain Cover (Difficulty: 2)
With the timing system in place, the next step was to put the timing chain cover back in place then tighten (8) 10mm bolts. After that we put the outer crankshaft belt pulley in place and tightened the (3) 13mm bolts. This step was fairly easy not requiring much skill which is why it has a difficulty rating of 2. During assembly this would have to be done after the rotating assembly and the rest of the timing system was assembled. This step followed the exact same instructions as the dis-assembly.
The first step of the reassembly was putting the camshaft back into place. After that we put the entire rotating assembly together before we put the timing gears back over the camshaft. Once the gears were in place we connected the timing chain to the timing gears and then put the protective timing chain cover over the entire assembly.
Reassembly of the Valve Train
Cylinder Head (Difficulty: 3)
The cylinder head is the first item to be put back onto the engine in the valve train. When originally assembling and reassembling the cylinder head a gasket must be placed in between the head and engine block to eliminate the leakage of fluids and vapors as well as make a tight seal in between the two parts in order to work properly. We used a 3/8 inch socket wrench to tighten the seven 13 mm head bolts attaching the cylinder head to the engine block. The outer two head bolts are shorter than the other five and it is important that they are placed in the correct place to secure the cylinder head properly. Due to the heavy weight of the head, a partner must hold it in place while securing the bolts. This is why the difficulty given to this process is 3.The assembly was performed almost exactly the same as the disassembly making it fairly simple to do.
Exhaust Manifold (Difficulty: 2)
The installation of the exhaust manifold was slightly easier to reassemble then it was to disassemble but was similar. So this has a difficulty of 2. For this process we used a 14 mm socket wrench to tighten the 6 bolts connecting the exhaust manifold to the cylinder head. This had to be done twice, once on each side, being that there are two exhaust manifolds on the engine block. It helped when one person was holding the manifold in place being that it is fairly heavy. If we had the intention of running the engine, it is necessary to put gaskets in between the exhaust manifolds and the engine block to eliminate leaks. This would have been done in the original assembly of the engine.
Push Rods (Difficulty: 1)
The push rods are very simple to reassemble and it is similar to the way it was disassembled. Place each one, six on each cylinder head (12 in all), in its respective slot opposite the valve spring. The hole which the push rod is placed in should go all the way down to the lifter which is connected to the camshaft. This does not require any tools and is extremely simple which is why it is given a difficulty of 1. This is how the push rods would have been originally installed.
Rocker Arms (Difficulty: 3)
For the reassembly of the rocker arms we used a 3/8 inch socket wrench to tighten the bolts on top each of the rocker arms. The bolt seat is placed in first with the bolt following so that the bolt has a flat surface to sit on. But you must check first that the end with the rounded indentation is placed on top of the push rod so that the valves will open and close properly. This is how it would have been assembled in the factory. We found that the reassembly of the rocker arms was the same but much easier than the disassembly of them so we gave it a difficulty of 3. It still took a fair amount of time because of the six rocker arms (12 in all) on each of the two cylinder heads but the process was easier.
Valve Cover (Difficulty: 1)
The two valve covers are the last things put back onto the cylinder heads. The way this was done is the same as the disassembly and same to the way it was assembled in the factory. A 3/8 inch socket wrench must be used to tighten the three bolts on each cover (six in all). This step was very easy to do because the valve covers sat in place and the bolts only had to be tightened. It was not time consuming or difficult which is why we gave it a difficulty of 1.
After we had the timing system in place we put the cylinder had back over the cylinders, then we put the exhaust manifold into place. After that we put the push rods back in place so they were touching the camshaft and then put the rocker arms over them. Finally we put the valve cover over the entire system to protect it.
Reassembly of the Air Intake System
Intake Manifold (Difficulty: 2)
The first thing that must be put onto the engine in this system is the intake manifold. This is because everything else sits on top of it. The manifold sits into place on the engine block and must be tightened into place with eight 13 mm bolts using a 3/8 inch socket wrench. If the engine was intended to run, a gasket must be placed in between the engine block and the intake manifold to eliminate leaks and create a secure seal for the manifold. In the original assembly of this piece, there would have been a gasket placed in between the manifold and the engine block as stated above and is made so that it can be taken off and switched but the manifold itself cannot be disassembled any further because of it being made of one solid piece. The whole process was very simple and almost exactly executed as the disassembly but due to the weight of the manifold, we gave it a difficulty of 2.
Fuel Injection Subsystem (Difficulty: Unknown)
Because we were not able to disassemble this piece during the dissection, it was not necessary for us to reassemble this piece that is why it is given an unknown difficulty. We were not able to disassemble the fuel injection subsystem because we were not able to reach the bolt that had to be loosened with the tools we had.
Distributor (Difficulty: 1)
This installation of the distributor is very simple. Place the thin end down into the slot in the back of the intake manifold. It is then secured by a 10 mm bolt using a 10 mm wrench. It cannot be tighten with a socket wrench because of clearance issues. Originally in the factory, the distributor would have been lubricated at the end where the gears are so that friction is reduced but since we are not running the engine this step is not needed. Because of the ease of reassembly we gave it a difficulty rating of 1. It was also just as easy to disassemble this piece as it was to put back together because we followed the same procedure.
Manifold Cover (Difficulty: 3)
When disassembling the manifold cover, we discovered that the cover was missing four of the ten bolts needed to fully secure the manifold cover down. Even though we could not find the missing bolts it was still very secure to the intake manifold but when the engine was originally manufactured, it had all ten bolts as well as the cover being able to be removed when needed. When tightening the ten 10 mm bolts, use a 10 mm wrench to tighten them down. The cover should fit right into place matching up with the holes for the bolts to go into. Next the fuel injectors can be installed into the fuel inlet passages on the intake manifold by simply pushing them until they click into place. Because of the time spent to secure the bolts and install the fuel injectors, we gave this process a difficulty of 3. In the original assembly of this product, it would have had all the necessary bolts but all in all the same as we did here. The assembly was also the same as the disassembly in the way that we just loosened the bolts and took it off.
Throttle Body (Difficulty: 1)
This would be the last item put onto the engine in our assembly, as well as the original factory assembly which is the same as we did here. The throttle body is made to be able to come off in order to service the engine in the event of something going wrong inside of the engine or cylinder heads. It attaches to the manifold cover with three 10 mm bolts which can be tightened with a 10 mm socket wrench. Place the throttle body on the cover in the appropriate slot and secure it with the three bolts in each corner (one corner does not have a bolt). Also, a gasket would have been placed in between the throttle body and the intake manifold in the original assembly. So because this is a very simple step it is given a difficulty level of 1. It was very simple to disassemble and to assemble being that there are only three bolts that attach it to the manifold cover which was the same as the disassembly process.
After we had the valve train back in place we moved on to the air intake system which started with intake manifold, we then put the fuel injector system back into place. After that we had to put the distributor and intake manifold cover into place. Finally we put the throttle body on top of the intake manifold cover.
Reassembly of the Cooling System
Electric Water Sensor (Difficulty: 1)
To install the electric water sensor all you do is put in place and then tighten (2) 10mm bolts which is why this step has a difficulty of 1. This would be one of the final steps of an assembly and may be done by hand. Putting this component back we just followed the dis-assembly instructions backwards.
Thermostat (Difficulty: 1)
Just like the electric water sensor, to install the thermostat you simply just put it in place and tighten (2) 10 mm bolts so this step also has a difficulty 1. Also like the electric water sensor, this would be one of the last components to be installed on the engine and may be done by hand. This step was done by doing the dis-assembly process in reverse.
Water Pump (Difficulty: 2)
In order to install the water pump we into place and hold up while (4) 14mm bolts are tightened by another group member. This step has a difficulty of 2 because the water pump is slightly heavy and it needs to be held till at least 2 of the bolts are tightened. During an assembly this could be done any time after the timing chain cover is put in place. This step was similar to the disassemble except the we had to hold the water pump to line it up with the bolt holes.
The final system we put back onto the engine was the cooling system, we started by putting the electric water sensor into the intake manifold along with the thermostat. The last step of the reassembly was putting the water pump back into place on the front of the engine.