Group 3 - GM V-6 Engine 1
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This section will provide background regarding the engine as well as plans to disassemble the engine.
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.
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