Group 11 - GM V-6 Engine Gate2

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Contents

Dissection Process

Preliminary Project Review

The actual process of dissecting the motor went almost exactly as planned in terms of process. The process, originally outlined in the work proposal, was very similar to the process that actually took place. However, there were a few parts omitted in the work proposal that needed to be removed. The pulleys were not mentioned as needing to be removed, but the removal of these pulleys proved to be a fairly elementary task that posed no major issues. Also, the removal of the harmonic balancer was originally omitted from the work proposal. This proved to be an omission of much greater importance. The removal of the harmonic balancer was a difficult task that was both physically strenuous and technically taxing. The removal of this piece took about forty five minutes, including a discussion between group members present on the best way to remove the part. Still, once this issue was resolved, the dissection went smoothly according to the process outlined in the work proposal.

One of the major difficulties originally identified by the group can be found in the work proposal. It states, “ensuring that all the small components are kept in an organized manor where they can be found easily for reassembly could prove to be a challenge.” This was a constant concern for the group, some of the members used many Ziploc bags and garbage bags with labels to ensure that the bolts and components could be easily located and reassembled when necessary. Another difficulty was not originally identified. The removal of the flywheel turned out to be more difficult than had been anticipated. This was due to the small amount of space between the flywheel and the engine stand. Still, this difficulty was overcome by the group in a relatively short amount of time.

The group members worked very well together on this gate. That can be said for both the disassembly of the engine and the construction of the gate. Each member contributed their part of project within the specified time. Also, no conflicts have arisen between group members to this point.

The major issue that arose during the dissection of the engine was a lack of communication between group 10 and group 11. No plan for working together was outlined in the work proposal which proved to be a major weakness for the dissection. Although not outlined in the work proposal, it was agreed between the project managers that each group would remove a head from the top of the motor and at that point the bottom of the motor would be divided between the two groups. It was also stated that group 11 planned on working mostly on Mondays and Wednesdays, while group 11 planned on working on Tuesdays and Thursdays. As per the original plan, group 11 went into the lab on October 4th, around 11:00am, and began dissecting the motor. The top of the motor was removed and then a head was removed. After that, the intake manifold and intake manifold cover were reattached in order to allow the other group to disassemble it as well. On October 11th, the group again returned to the lab to see how far the other group had progressed on the dissection. They had not begun the dissection at this point. At this point, the project manager decided to go ahead and began taking apart the front of the motor. The water pump and the pulleys were removed. The timing chain cover was also unbolted, but the harmonic balancer was still on the crankshaft so it could not be removed. No one in the group was sure on the proper way to remove the harmonic balancer. The group stopped for the day and decided to meet again on Wednesday, however the meeting on Wednesday was later canceled due to scheduling conflicts. A meeting to work on the project was scheduled for October 18th, a week before the gate was due. The assumption at that point was that group 10 would have been to the lab and begun dissecting the motor. At this point, the two group managers should have met and discussed this, but no such meeting took place. On Monday October 18th, the group met up in the dissection lab at about 11:30am only to find that group 10 still had not begun the dissection. At this point, the group members needed to make a decision. They could either wait until Wednesday and hope that group 10 planned on working in the lab on the 19th , or they could get as far on the dissection process as possible and then talk to group 10 and provide them with all the information needed. If the group waited until the 20th and group 10 still had not begun the dissection, then the entire bottom of the motor would have to be dissected in three hours. This option was deemed unacceptable and so the group proceeded on October 18th to begin the disassembly of the bottom of the engine. Once the harmonic balancer was removed, the dissection process went very smoothly and the dissection was completed by about two o’ clock. At that point, it was decided to talk to group 10 and offer them the notes on the process, the tools used, pictures, the difficulties encountered, and anything that they needed since they were not present for the dissection. In class, the group managers discussed the engine and the group manager from group 10 stated that his group planned to do the dissection this week. When the project manager from group 11 informed him that the dissection was completed and offered him and his group any assistance they needed, he stated that his group planned to reassemble the motor and then dissect it again and that they would let the group know what information was needed.

Clearly this situation necessitates much improved communication between the project managers of group 10 and group 11. In order to improve the communication between groups, group 11 plans to set a time each week where the two project managers sit down and discuss the plans for the project. This will help avoid these communication issues between groups in the future.

Difficulty Analysis

  • Difficulty is a quite subjective concept. As a result, any defined scale will be inherently subjective. So this scale is written for an individual who has average strength and minor technical knowledge. The difficulty of each step of the dissection is then to be divided into two different sections. The first is the physical difficulty. This involves the difficulty of the physical labor involved with removing an individual component. This is rated on a scale of one to five using the following table:

Table 1: Physical Difficulty Rating

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  • The second section of difficulty is the technical difficulty. This involves the intuitiveness of the tools needed to remove the part.

Table 2: Technical Difficulty Rating

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Table 3: Dissection process

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Step 1

  • The throttle body of the engine was removed using a 10mm socket and a ratchet with a 3/8in drive and counter-clockwise rotations until the bolts were completely removed from the threaded hole. A total of three 10mm x 4-7/16in bolts were removed with ease and no unforeseen challenges arose. The throttle body is located on the intake manifold towards the front of the engine. The throttle body is a lightweight part and required very little force to remove, so the physical difficulty was rated as a one. Only a socket and ratchet were needed to removed it, making the technical difficulty a two. The part was obviously design to be removed since it was held in place by several clearly visible bolts. The reason it was designed to be removed is so that maintenance can be easily performed to areas on the top of the engine block.

Throtin.jpg

Step 2

  • The distributor was removed without any tools. A threaded hole was present but there were no bolts securing the part to the engine. It is located on the top of the engine towards the back. The distributor extends down into the motor and is connected to the camshaft. The distributor was removed simply by lifting it up and out of its hole by hand. Since the distributor is plastic, very lightweight, and required no tools to remove, the physical and technical difficulty were both rated as a one. It is impossible to say whether or not it was designed to be removed since it was just placed back into the engine block without connecting it in any way.

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Step 3

  • The intake manifold cover was removed. This was located on the very top of the motor. Six, 10mm x 2-1/4in bolts were removed using a 10mm socket and a 3/8in drive ratchet and counter-clockwise rotations until the bolts were completely removed from the threaded hole. Once all of the bolts were removed, the cover was simply lifted off of the intake manifold by hand. This step required little mechanical knowledge and no unforeseen challenges arose. Since the intake manifold cover is plastic and lightweight, the physical difficulty was rated a one. The technical difficulty was rated a two since a socket and ratchet were necessary. The intake manifold cover was designed to be removed since it can easily be removed by taking off several obvious bolts. This is probably so that maintenance can easily be performed to the top of the motor.

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Step 4

  • The exhaust manifolds (qty. 2) were removed using a 9/16in socket with a 3/8in drive ratchet and counter-clockwise rotations until the bolts were completely removed from the threaded hole. These were located on the side of the engine. A total of twelve, six on each side, 9/16in x 1-1/2in bolts were removed using the socket and ratchet and the manifolds were lifted off by hand. This step required little mechanical knowledge and no unforeseen challenges arose. Since the exhaust manifold was fairly lightweight and easy to remove, the physical difficulty was rated as a one. The technical difficulty was rated as a two since a socket and a ratchet were needed. The exhaust manifold was designed to be removed since it can easily be removed by taking off several obvious bolts. This is probably because the exhaust manifolds are often changed by truck owners in order to alter the sound of the truck.

Exhaustmani.jpg

Step 5

  • The valve covers (qty. 2) were removed using a 1/2in socket with a 3/8in drive ratchet and counter-clockwise rotations until the bolts were completely removed from the threaded hole. These were located on the top of the motor on the top of the head. There were a total of six bolts, three on each side of the valve cover. Once the 1/2in x 2-1/8in bolts were removed the covers were easily lifted off by hand. No unforeseen challenges arose during this step. Since the valve covers are plastic and lightweight, the physical difficulty was rated as a one, while the technical difficulty was rated as a two because a ratchet and socket were needed. The valve covers were designed to be removed since they were held in place by three obvious bolts. This is probably so that maintenance can easily be performed to the top of the head.

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Step 6

  • The intake manifold was removed from the top of the engine. This was affixed to the top of the engine block with eight 1/2in bolts. These bolts were removed with a 1/2in socket with a 3/8in drive ratchet. After several counterclockwise turns, the bolts were easily removed. Once all bolts were removed from their threaded holes this part was lifted off by hand without any interference. The physical difficulty of removing the intake manifold is rated as a three because the intake manifold is of moderate weight. The technical difficulty was rated as a two because a socket and a ratchet were needed. The intake manifold was designed to be removed since it can easily be removed by taking off several obvious bolts. This is probably so that maintenance can easily be performed to the top of the motor.

Intakemani.jpg

Step 7

  • The heads (qty. 2) were removed using a 9/16in socket with a 3/8in drive ratchet and counter-clockwise rotations until the bolts were completely removed from the threaded hole. The heads were located on the top of the motor towards the sides. There were a total of sixteen bolts, eight on each head. The bolts toward the center of the engine block measured 9/16in x 2-1/8in while the bolts toward outside of the block measured 9/16in x 2in. Once the bolts were removed the covers were easily lifted off by hand without any interference. No unforeseen challenges arose during this step. The physical difficulty of removing the heads was rated as a two because a small amount of force was needed to remove them. The technical difficulty was rated as a two because a socket and ratchet were needed to remove them. The heads were not designed to be removed by the average person. This can be seen by sheer number of bolts and the difficulty accessing them. This is probably so that a consumer does not take the heads of and allow dirt and grime to fall down into the motor thereby jeopardizing the longevity of that engine.

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Step 8

  • The push rods were removed from the engine block. These were located on the inside of the head. After the heads were removed, all twelve of the push rods were easily removed by hand as they were not affixed securely to any part of the engine block or the engine’s sub-system. No unforeseen challenges arose in this step. Since no tools were needed and the push rods were easily removed by hand, the physical difficulty and the technical difficulty were both rated as ones. The push rods were not designed to be removed since the heads were not designed to be removed. This is probably to prevent damage to the internal working of the motor.

Pushrod.jpg

Step 9

  • The rockers were removed from the inside of the heads. Each rocker was held on by a 1/2in nut. These were removed by using a 1/2in socket with a 3/8in drive ratchet and then completing multiple counterclockwise rotations. Underneath the nut was an ordinary washer. The washer was removed by hand. Once the washer was removed, the rocker was easily removed from the valve train. On top of the rocker sat a roller which fell right off as soon as the washers were removed. No unforeseen challenges arose in this step. The removal of the rockers required a socket and a ratchet, which made the technical difficulty a rating of a two. The physical difficulty was rated a one because the rockers were very lightweight. The fact that they were held in place by only a nut and washer indicates that they were meant to be removed. This was probably so that aftermarket rockers could be added to the engine, as is common practice.

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Step 10

  • The water pump was removed from the front of the motor. The water pump was affixed by four 9/16in bolts. These bolts were removed using a 9/16in socket with a 3/8in drive ratchet. After several counter clockwise rotations, the bolts were easily removed and the water pump could be lifted off by hand. No unforeseen challenges arose in this segment of the dissection.The physical difficulty was rated as a one because the water pump was fairly lightweight. The technical difficulty was rated as a two because a socket and a ratchet were needed. The water pump was designed to be removed since it can easily be removed by taking off several obvious bolts. This is probably so that maintenance can easily be performed to the front of the motor.

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Step 11

  • The serpentine pulley attached to the harmonic balancer and crankshaft was then removed. This was affixed by three 9/16in bolts. These bolts were removed using a 9/16in socket and a 3/8in drive ratchet. After several counterclockwise rotations, the bolts were easily removed. No unforeseen challenges arose in the segment of the dissection. Since the pulley is fairly lightweight, the physical difficulty was rated as a one, and the technical difficulty was rated as a two since a ratchet and a socket were required to remove the part.The serpentine pulley was designed to be removed since it can easily be removed by taking off several obvious bolts. This is probably so that maintenance can easily be performed to the front of the motor.

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Step 12

  • The oil sensor was then removed. This was affixed to the engine block by two 1/2in bolts. These bolts were removed using a 1/2in socket and a 3/8in drive ratchet. After several counterclockwise rotations, the bolts were easily removed. No unforeseen challenges arose in this segment of the dissection. The physical difficulty was rated as a one because it was lightweight and the technical difficulty was rated as a two since a ratchet and socket were needed. The oil sensor was designed to be removed since it can easily be removed by taking off several obvious bolts. This is probably so that the oil pan could be accessed.

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Step 13

  • No part was removed in this step. The motor was rotated 180 degrees to expose the underside of the engine. This step required a moderate amount of strength to slowly rotate the engine. The rotation of the engine required no tools other than the engine stand, so its technical difficulty was rated as a one. Since it was a fairly physically demanding process, the physical difficulty was rated as a four.

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Step 14

  • The oil pan was then removed from the bottom of the motor. The oil pan was affixed to the bottom of the engine block by ten 1/2in bolts. These bolts were removed using a 1/2in socket and a 3/8in drive ratchet. After several counterclockwise rotations, the bolts were easily removed and the oil pan was lifted off by hand. No unforeseen difficulties arose. Since the oil pan is fairly lightweight, its difficulty was rated as a one,while the technical difficulty was rated as two because a socket and a ratchet were needed to remove the part. The oil pan was designed to be removed since it can easily be removed by taking off several obvious bolts. This is probably so that maintenance can easily be performed to the bottom of the motor.

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Step 15

  • The oil pump was then removed from inside the oil pan. This was affixed by two 5/8in bolts. These bolts were removed using a 5/8in socket with a 3/8in drive ratchet. After several counterclockwise rotations the bolts were removed and the pump was lifted out by hand. No unforeseen challenges arose. The removal of the oil pump had a physical difficulty rating of a one because it was lightweight and easy to remove. The technical difficulty was rated as a two since a ratchet and a socket were needed. The oil pump was designed to be removed since it can easily be removed by taking off several obvious bolts. This is probably so that it can easily be replaced on the motor.

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Step 16

  • The harmonic balancer was removed from the front of the motor. The harmonic balancer was affixed to the crankshaft using a keyway. The harmonic balancer was removed by repeatedly tapping it with a hammer. Eventually, the component was removed from the motor. This process was much more difficult than the group had anticipated. It was much more time consuming and physically strenuous than had been expected. The group had anticipated a bolt or some other basic fastener to be present, but the presence of a keyway made things much more difficult. Since the process was somewhat difficult and required a good amount of force, the physical difficulty was rated as a three. The technical difficulty was rated as a three because it was not obvious which tools were needed. The harmonic balancer was not designed to be removed from the motor. This can be seen by the great difficulty the group had removing it.

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Step 17

  • The timing chain cover was then removed from the front of the engine block. This was accomplished by removing six 1/2in bolts with a 1/2in socket with a 3/8in drive ratchet. Once the bolts were off, the cover was lifted off by hand posing no further complications. The removal of the timing chain cover was rated as a one is the physical difficulty department because it was lightweight and fairly easy to remove. The technical difficulty was rated as a two because a socket and a ratchet were needed to remove the part. The timing chain cover was designed to be removed since it can easily be removed by taking off several obvious bolts. This is probably so that maintenance can easily be performed to the front of the motor.

Timingchcov.jpg

Step 18

  • The sprocket attached to the camshaft was then removed. This was located inside the timing chain cover at the front of the engine. This was affixed by three 9/16in bolts. These were removed using a 9/16in socket and a 3/8in drive ratchet. After several counterclockwise rotations, the sprocket came right off of the cam shaft. No unforeseen difficulties arose in this part of the dissection. The physical difficulty was rated a one because the part was lightweight and easy to remove. The technical difficulty was rated a two because a socket and a ratchet were needed to remove the part. The sprocket was designed to be removed since it can easily be removed by taking off several obvious bolts. This is probably so that the timing chain could be easily removed for maintenance.

Timch.jpg

Step 19

  • The timing chain was then removed. After the sprocket was removed, the timing chain was easily taken off the by hand. This process was much easier then the group had anticipated. since the timing chain was lightweight and required no tools to remove, both the technical and physical difficulty were rated as ones. The timing chain was designed to be removed since it was easily removed from the motor. This was probably so it could be easily replaced.

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Step 20

  • The cam retainer was then removed. The retainer was held in place by two T30 Torex bolts. Once the bolts were removed with a T30 socket with a 3/8in drive ratchet, the cam shaft was free to be taken out. No unforeseen challenges arose. The cam shaft retainer was a lightweight part and required little force to remove, which gave it a physical difficulty rating of a one. Since a T30 Torex socket was used the technical difficulty rating was rated as a four, since this was a specialized tool. This was not designed to be removed since it was held in with T30 Torex bolts. This is probably so that the cam shaft will remain insde the engine.

Camretain.jpg

Step 21

  • The cam was then removed. This was done by pulling the cam straight through the front and out of the engine block. No unforeseen difficulties arose in this process. Since the cam shaft is of moderate weight, the physical difficulty rating was a three. Since no tools were necessary, the technical difficulty was rated as a one. This was not designed to be removed since it was held in with T30 Torex bolts. This is probably so that the cam shaft will remain insde the engine and no grit or grime is able to enter the engine.<

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Step 22

  • The balancing shaft was then removed. A T30 Torex bit was needed to loosen the Torex bolts that bolted the balancing shaft retainer to the engine block. After that, it could easily slide out of the top of the motor after it had been tapped by a hammer. No unforeseen difficulties arose in this process.Since a T30 Torex bit was needed, the technical difficulty was rated as a four, because that is a specialized tools. Since it only required a slight amount of force to remove, the physical difficulty was rated as a two. This was not designed to be removed since a T30 Torex bolt was used to hold it in place. This is probably because the part is not vital to the operation of the motor and could be forgotten on reassembly.

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Step 23

  • The flex plate was then removed. There were a total of seven 5/8in bolts that needed to be removed. This was accomplished with a 5/8in socket and 3/8in drive ratchet. Once all of the bolts were removed the flex plate was lifted off of the crankshaft. Since the flexplate was very difficult to get to and it was physically difficult to get to the bolts that needed to be removed, the physical difficulty was rated as a four. The technical difficulty was rated as a two because only a socket and a ratchet were needed to remove the part. This part was designed to be removed since it was held in place by obvious bolts. This is probably so that an aftermarket flex plate can be installed.

Flexplate.jpg

Step 24

  • The connecting rods were disconnected from the crankshaft next. The rods were affixed to the crank by two 9/16in nuts and bolts. This was removed using a 9/16in socket and a 3/8in drive socket to remove the nuts that held the connecting rod retainer to the rest of the connecting rod. Once the nuts were removed, the retainers were pried off using a flat head screw driver. Upon removing the nuts, the rods and pistons were now able to be moved by hand within the cylinder wall. After much coaxing and the use of a hammer, the pistons were pushed out of the top of the cylinder. This step required moderate physical force to turn the crankshaft in order to expose the retainers that needed to be removed. Although this step required moderate physical force and technical skill no unforeseen challenges presented themselves during this step of disassembly. Due to the sheer weight of the crankshaft, the physical difficulty was rated as a five. Since intuitive tools were needed, but it was somewhat unclear at times what tools, the technical difficulty was rated as a three. The crankshaft was clearly not designed to be removed. The use of so many bolts and retainers shows that it is designed to stay inside the engine. This probably to prevent any foreign substance from entering the engine.

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First Level Subfunctions

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Figure 1: First Level Subfunctions

Second Level Subfunctions

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Figure 2a: Second Level Subfunctions.

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Figure 2b: Second Level Subfunctions.

Connection of Subsystems

When looking at each of the individual subsystems of the GM V6 motor, all directly interact with the motor itself and are key to its proper and efficient functioning. These subsystems include the intake and exhaust system, the electrical system, the lubrication system, the drive system, and the combustion system. The systems that provide mechanical energy to the vehicle power the electrical system and maintain proper engine functioning. Physically, all systems are linked to one another through the crankshaft, which rotates in the center of the engine and is responsible for all processes that the motor produces. Further, this crankshaft spins pulleys and pumps that are connected by belts. This in turn spins other pumps or an alternator to produce electrical and power the elctrical system. The initial first level functions that involve fuel, air, and a signal input interact with lower level functions by directly starting the engine in order to perform further functions. The first system is the intake and exhaust system. When this system is activated, air will flow into the piston and gas will be injected in through the fuel injector. Once the mass flows into the cylinder, it is compressed by the piston system and then combusted by the spark plugs. The combustion reaction forces the piston downward which activates the drive system. The piston being forced downwards causes the crankshaft to spin which causes the lubrication system to to activate. The oil pump then lubricates the engine components. The crankshaft is connected to the cam shaft via the timing chain where it spins and causes the opening and closing of the valves which allow the intake and exhaust of air inside the motor. The signal from the operator is directly transmitted by the turn of the key to the engine. Also, the when the crankshaft spins, the alternator is spun and electricity is distributed to the spark plugs causing a spark.

Mass can be seen connected to the systems in the crankshaft. The crankshaft is a weighted and balanced object; it produces power by pulling on the pistons and in turn opening and closing the valves. This process uses both the air and fuel present in the initial starting process, and the power produced in both the first and second level systems. Energy is a connection which is made between every system. Initially, electricity is imported into the system via the starter, which converts the electrical energy to mechanical energy. This mechanical energy continues through the motor and combines with the combustion of fuel and air in the valves and pistons producing additional mechanical energy. This mechanical energy continues into the engine to power oil pumps, the coolant system, pulleys and belts, resulting in the involvement of itself in every system of the engine. The mechanical energy is again turned into electrical energy through the use of an alternator connected to the motor\'s belt. Electrical energy is converted from mechanical energy in the distributor. As the camshaft spins, it spins the distributor sending electricity to the spark plugs to ignite the fuel in the engine, directly interacting with all other systems of the motor. This linking of all of the engine’s systems makes for an efficient combustion process and use of input factors.

The connection of systems in a motor is vital to its functioning and efficiency. The initial systems involve the input of air and fuel for the following reason; direct connection is the only method for such factors to be introduced to the other systems. Since all of the systems run off of each others\' energy, mechanical, electrical and chemical energies can only be transported in an engine through connection of systems. Each system runs off of one another, making other devices unnecessary to complete the task. This causes an increase in the energy needed for the motor and vehicle to perform. In systems where a fan, oil pump or other subsystem are powered by a battery or other power source, the surplus energy of the motor can be utilized instead of consuming additional energy. To a certain extent, an engine can sustain the subsystems attached directly to it but when systems become too large, in some cases, they can cost the motor power and efficiency. That is the reason for a well-designed engine. In addition, systems are connected because they keep the motor in balance and running smoothly as revolutions increase or decrease. There are different requirements to keep it running. If a system were not directly linked to the engine, it might not properly read the engine\'s needs and efficiency would lag as a result.

The subsystems are all connected more or less through the cam shaft, timing chain, and crankshaft. The reason for this is so that all the subsystems are activated at the proper time. For example, the engine intakes air at the proper time because the camshaft is spun by the crankshaft. This means that the intake will occur at the exact proper time each time. The piston system is connected to the drive system through a retainer and Torex bolts that attach the connecting rods to the crankshaft. This is done in order to ensure that the energy from the chemical reaction translates into mechanical energy and the turning of the crankshaft.

The fact that the subsystems are connected in such a well organized fashion is indicative of a concern for economic factors, particularly fuel economy[9]. In order to have optimum fuel efficiency, the engine must be well maintained by these subsystems. For example, if the distributor is sending the charge to the spark plug at the wrong time, a misfire could result. This would adversely affect the fuel economy and could even damage the piston. Therefore, having the systems connected properly in the motor helps both fuel mileage and durability. The fuel mileage could also be affected by the societal factors caused by an increased consumer desire for fuel economy.

The subsystems are arranged in this manner due to the nature of there duties. Obviously, since the drive system connects to the intake and exhaust system through the timing chain, these two system need to be placed in close proximity to each other. Also, the lubrication system needs to be placed near the drive system since it is run off of it. Since the intake and exhaust system require lubrication as well, it also needs to be placed near the drive system. As a result, the lubrication system, the drive system, and the intake and exhaust system are placed in close proximity to each other. Also, some subsystem can not be put adjacent to each other. For example, the electrical system can not be put adjacent to the lubrication system inside the oil pan because it will damage the alternator and will interfere with the electric signals being sent from the alternator.



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