Group 7 - GM 2.2L 4-Cyl Engine Gate 2
To return to Group 7's main page click here: Group 7 Main Page
To go back to gate 1 click here: :Gate 1: Product Planning
To move on to gate 3 click here: :Gate 3: Product Analysis
To move on to gate 4 click here: :Gate 4: Product Reassembly
Our work proposal went smoothly as planned. Our "top to bottom" dissection plan was successful, and we were able to keep organized by our strategy which was to "place each part in labeled zip-locked bags", along with documenting specific tools and removal difficulty for each part.
One problem our group encountered during dissection was not knowing the name of each specific part as we dissected it. This created some challenges organizationally, since some parts/dissection methods were identifiable already by name and others were assigned numbers. We were able to discover the names of these unknowns parts by matching up the serial number with an online search for the part, and via matching it up with detailed car engine diagrams we found online. This is an issue we could have initially prepared ourselves more for knowing our group's initial shortcomings in our inexperience with working directly with car engines.
Our collaborative work proposal with group 18, given the initial parameters and the individual shortcomings we were already aware of, worked smoothly, and we were able to dissect the entire engine. Group 18 dissected the engine Wednesday the 19th and Monday the 24th, and group 7 dissected the engine Thursday the 20th during the respective available lab hours on each day. On each day a member of the opposite group was present to document the group's progress, i.e. on Wednesday and Monday Adam Lawyer was present to document group 18's progress and on Thursday Yong Chi Lim was present to document group 7's progress. Adam and Yong collaborated to create a full disassembly process with everyone's work incorporated for official documentation.
Below is our step-by-step process dissecting the engine, detailing the part removed, with what tools it was removed, the ease of disassembly, and whether the part was intended to be disassembled. Some larger parts are omitted from the tables below because the disassembly occurs inside of them.
Our ease of disassembly metrics are based on a scale of 1 to 3 and is relative to our group's experience level. This scale is given with respect to the difficulty of removing the individual component in and of itself, but not with regards to how many other steps would be required to remove the part; for example, a part could easily be removed by loosening two or three bolts but it may require a majority of the engine to be disassembled. While this was not factored into our numerical scale, these instances were documented in the table below where necessary. The specific metrics are listed below.
|1||No tools or very little tools required. Low level of physical strength as well as very low critical thinking.|
|2||Some basic tools required, some thinking was required and low to moderate physical strength was required.|
|3||Multiple tools were required, and either an above average amount of physical strength was required to remove, or a level of thinking that goes beyond the technical experience of our group members.|
Step 1-15: Group 18
Step 16-22: Group 7
Step 23-25: Group 18
|Step #||Part Name||Removal Method/Tools||Ease of Disassembly||Intent for Removal||Part Photograph:|
|1||Intake Assembly||10 mm socket wrench, loosen nuts to remove||2||This part was intended to be easily removed; the disassembly process was basic and the assembly could be removed by one person.|
|2||Throttle Body||10mm socket wrench, loosen nuts||2||This part was intended to be easily removed; the disassembly process was basic and the assembly could be removed by one person.|| Sample photo:|
|3||Fuel Rail Assembly||10mm socket wrench, loosen nuts||2||This part was intended to be easily removed; the disassembly process was basic and the assembly could be removed by one person.|
|4||Oil filter/dipstick||Manual, use hands||1||This part was intended to be easily removed, since no tools were required and the part basically popped right off.|
|5||Coolant Tube||15 mm socket wrench,
|2||Though the fastening was simple, this part was not designed to be easily removed, as there are many surrounding parts and great care was needed to do it properly.|
|6||Engine Ignition Coil||13 mm socket wrench, loosen nuts and bolts for removal||2||This part was intended to be easily removed, evidenced by the simplicity of fastening, the low weight, and its location on the engine block.|
|7||Exhaust Manifold||10mm socket wrench; unscrew hex nuts||2||This part was intended to be easily removed, evidenced by the simplicity of fastening, basic tools required for removal, and its location on the outside of the engine block, making it a distinguishable and easily removable part.|
|8||Water Pump||13mm socket wrench to loosen nuts and bolts||2||This part was not intended to be easily removed. Although the fastening methods were simple, the location and size of the pump made it difficult to remove without a degree of meticulousness.|
|9||Purge Solenoid||13mm socket wrench to loosen nuts and bolts||2||This part was intended to be easily removed, evidenced by the simplicity of fastening, the part's light weight and its distinguishable location on the engine block.|
|10||Engine head cover||10mm screws, pulled off easily||1||This part was designed to be removed easily, evidenced by the simplicity of fastening and its location atop the engine.|
|11||Belt Wheel||15mm socket wrench, loosen bolts. 17mm socket wrench for center bolt||1||This part was intended to be easily removed, evidenced by the simplicity of fastening and its location on the outside of the engine block. Since the belt wheel was of medium size relative to other parts on the engine, it was quick to remove.|
|12||Rocker Arm/push rod||10 mm socket wrench, 1/4" drive ratchet. Loosen bolts, take out rod with hands||2||Though the fastening methods appear simple enough, this part was not intended to be easily removed, due to the fact that it could not be disassembled without removing several other major engine components.||Rocker Arms:|
|13||Mounting Bracket||15 mm socket wrench, 1/2" drive ratchet, remove bolts||2||This part was intended to be easily removed, evidenced by the simplicity of fastening, the basic tools required, and its location on the outside of the engine. This part could have been removed earlier.|
|14||Mounting plate||8mm screws, screwdriver||2||This part was intended to be easily removed, evidenced by the simplicity of fastening and basic tools required for removal.|
|15||Engine Block||Assortment of screws/wrenches, came out by hand||2||Though the fastening was simple, the engine block is not a component that was designed to be easily removed, as it took multiple people to remove the block due to its weight.|
|16||Oil Pan||10 mm socket wrench, 1/4" drive ratchet, loosen bolts for removal||1||This part was intended to be easily removed, evidenced by the simplicity of fastening and basic tools required for removal. The part is very light and popped right off after removing the bolts.|
|17||Oil Pump Assembly||15mm socket wrench, 1/2" drive ratchet,unscrew bolts||2||This part was intended to be removed, evidenced by the simplicity of fastening and basic tools required for removal. However, some disassembly was required of other engine components to access this component, so its removal is slightly more complex.|
|18||Oil Temperature Sensor||1/4" drive ratchet, 8mm socket wrench, unscrew small bolts/nuts||2||This part was designed to be removed, evidenced by the simplicity of the fastening|
|19||Crankshaft Clamps||Unscrewed bolts with 15mm socket wrench, 1/2" drive ratchet. Tapped out with hammer||2||This part was designed to be removed, evidenced by the simplicity of the fastening. However, this part is deep within the engine and requires taking apart a majority of the components to gain access. They are also integral to a major part of the engine in the crankshaft. Therefore its removal, while possible, is not meant to be easy. It became easy once a majority of the engine was disassembled.|
|20||Push Rod Guides||1/4" drive ratchet, 10mm socket wrench||2||This part was designed to be removed, evidenced by the simplicity of the fastening, but like the crankshaft clamps, a good portion of the engine had to be disassembled to gain access to remove the push rod guides.|
|21||Push Rod Seats||Manual removal by hand||1||This part was designed to be removed easily after the guides were removed|
|22||Piston Clamps/Pistons||1/2" drive ratchet, 13mm socket wrench, vicegrips for clamps. Tapped pistons out with hammer||3||This part was designed to be removable, but only after a majority of the engine was disassembled. Even once our group took apart most of the engine, these parts were still more difficult than the others to remove. If a problem were to exist regarding the pistons in an engine it would require a professional to repair.|
|23||Crankshaft||Hammer, pin, applied pressure point to allow crankshaft to be removed by hand||2||This part was designed to be removed, evidenced by the simplicity of the fastening, despite the methodical approach taken by group 18. Again, a majority of the engine had to be disassembled, so it was only intended to be disassembled by a professional should there be a problem with this component.|
|24||Valve spring/valve||21mm socket wrenchpiece, hammer||3||This part was designed to be removed by alternative machinery, but group 18 took an unorthodox approach to removing it that was quite difficult.||Video of group 18 removing:|
|25||Piston rings||Pliers||1||This part was designed to be removed by an average user evidenced by the simple methods of removal, should they ever need to remove the piston rings, which is unlikely.|
Neither group 18 or group 7 were capable of removing the timing gear cover and harmonic balancer off of the crankshaft. We determined that these parts were not intended for removal but provided the proper tools and, if necessary, they could be removed by an experienced mechanic.
Photo here: in the photo, the clover-shaped object in the middle is the harmonic balancer, and the large silver component is the timing gear cover.
Connection of Subsystems
What subsystems are connected and How?
The first subsystem in our engine is the intake system, which is made up of the fuel injectors, fuel pump, spark plug, intake cam, intake valve, and throttle. This system is responsible for the starting of the engine. This is connected directly to the power supply system physically and through mass and signal. The power supply system is the pistons, cylinders, crankshaft, and push rods/ rocker arms. This uses the signals from the intake system to create motion and give power to the vehicle. The power system works directly with the cooling and lubrication systems. The cooling system consists of the water pump and coolant tube. This injects water into the power supply so the engine does not overheat. This is connected physically and through mass. The lubrication system is made up of the oil pan, oil temperature sensor, oil filter, and oil pump. This system is in charge of keeping the crankshaft and pistons lubed so they can move smoothly and with little friction. This system is connected to the power system through mass and physically. The exhaust system is also connected the power system physically. This is made up of the exhaust valve, exhaust cam, and exhaust manifold. The last subsystem is the engine body. The components of this system are the engine head cover and the oil pan. This physically holds all of the other subsystems.
Why are they connected?
The subsystems involved in an automobile engine are primarily connected to allow for efficient transfer of energy from one system to another. All of the subsystems are connected by physical contact and they are signaled by motion of the previous subsystem as opposed to any electrical or chemical signals. Within these subsystems there are other smaller subsystems that involve chemical and electrical signals, but the overall subsystems involve the physical transfer of energy. If the subsystems were not connected to each other, there would be no energy transfer and the engine would not work. Because the energy is transferred through each subsystem, if one system fails to transfer the mechanical energy properly the whole engine will fail. The subsystems are designed to allow for efficient energy transfer from one subsystem to the next so there will not be a large loss of energy through heat. If these subsystems were not connected in a such a way, large amounts of energy would be lost to heat or lack of proper energy transfer.
How are these connections implemented?
Each subsystem is physically connected to another through means of physical contact such as friction, bolts or welding, or they are connected with electrical wires. Other larger subsystems use bearings or larger connecting rods so that proper timing is achieved with the system. Proximity can also provide a means of connection within the engine. As demonstrated by the valve system and the piston-cylinder system, the valve simply covers an opening in the cylinder. These subsystems are simply connected by close proximity. Since each subsystem is connected to another, each one sends a signal and some form of energy transfer to the next subsystem. When the engine is started, an electrical signal connects the battery to the to the main starter solenoid which transfers a large amount of energy to the starter motor and this turns the main gear to start the motor and suck gasoline into the cylinders. When the engine is in use, the spark plugs are connected to the cylinders by means of an electrical signal which causes combustion of gasoline therefore moving the pistons. Here energy from expanding gases from combustion is transferred into translational energy in the pistons. The pistons are directly connected to the connecting rods which are connected to the crankshaft, and energy from the translation of the pistons is transferred to the crankshaft through the connecting rods and converted to rotational energy in the crankshaft. This rotational energy is transferred to rotational energy is the axle and wheels which finally converts to translational energy in the movement of the vehicle. With the exception of the spark plug, the combustion of gasoline and the expanding of gas, the main subsystems are all connected physically by bearings and connecting rods so they can efficiently transfer mechanical energy from one subsystem to the next. Many other subsystems are connected via electrical wires and physical connections like bolts and welded metal. Again, some energy is lost through heat produced by friction. The connections are very important in making the system work. If certain subsystems weren't connected, signals would not be transferred properly and subsystems would not be timed correctly within the whole system. This can be reduced by the use of lubrication between physical parts, but it cannot be fully eliminated.
How do global, environmental, economic and societal concerns influence this?
Economic concerns affect how the subsystems are connected because most companies designing and building the engines want to keep their costs as low as possible, so this would mean keeping the engine as small as possible. The companies designing the engine have to consider how each subsystem is connected and see how they can compact the entire system while still having efficient connections within the subsystems. This will allow them to keep costs lower. Global factors such as weather and climate can also affect the subsystem connections. Depending on the general weather patterns and climate of an area, the connections may have to be constructed differently with different materials or some connections may have to be covered up by some sort of housing so that climate does not cause the connections to degrade or corrode. This also fits in to economic concerns because engine and automobile companies need to consider types of materials used for connections when analyzing overall cost. Environmental concerns would also include analyzing materials used for connections and making sure that, after the engine is disposed of, the materials that were used are not harmful to the environment. Societal concerns influence the overall system of the engine and how each subsystem affects it. People are concerned with efficient energy usage and fuel consumption. People want to buy less fuel and have their vehicle utilize it more efficiently. Efficiency of connections and how well each one transfers energy comes into play here. The engine designers must consider the most efficient ways of transferring energy through connections with the smallest energy loss. Society and people also want to be able to buy cheaper vehicles, and so selection of materials needs to be considered here too. The engineers and designers need to consider the most efficient energy transfer, the lowest fuel consumption with the largest energy output, the materials used in the connections and they need to analyze exactly how everything is connected when addressing societal concerns in their main design. For our GM engine, global concerns can affect many of the connections because the engine is not insulated very well. Cold weather could affect the performance of many of the physical connections as some materials can become slightly deformed in very cold climates. Since the engine was built in 1982, its technology is not as advanced as many modern engines, and so the performance of the subsystems and their connections decreases. Environmental concerns would be how the connections were manufactured and how GM controlled the emissions and how the materials for the connections were obtained. Economic concerns for our engine and the connections include cost of the many metal materials used for connections and cost of the electrical systems and the wired used to connect them. Less sophisticated connections such as the push rod and rocker arm probably cost less than an electrical wire connection would have cost in order to control valve timing. If the connection does not reach the same cost, then surely an electrical timing system used with this connection would have increased the price. Societal concerns involved in the engine's subsystem connections include the use of connections that are fuel efficient. Our engine does not fully address the current societal concerns for an automobile engine, so things that could be improved are many of the subsystems and the connections in order to make it more fuel efficient. The engine could use a more efficient valve timing system with electrical connections instead of physical connections and many other physical connections can be interchanged in the same way with increased technology. Many design concerns with our engine arise from the fact that the engine was built almost 30 years ago and the technology was not as advanced as today.
How does performance influence the connection type?
Performance influences the connection type of our four subsystems because they must be connected in an efficient manor. This includes both cost and maximization of the capabilities of the engine itself.
- Intake Valves: In order to maximize the function of the engine, the intake values must be able to seal shut so that during compression, no fuel or air leaks out. It is imperative during this stage that the intake value is able to remain sturdy in order to allow for a great increase in pressure. This means that the valves must be able to withstand a wide array of both environmental and normal wear and tear
- Fuel Lines: In order to maximize the function of the engine, the fuel line must be able to be very sturdy. The fuel line, which transfers fuel into the cylinder, is generally made of a high strength rubber. This rubber must be sturdy enough that it will not puncture easily or knot up.
- Spark Plug: The spark plug must maintain similar performance features as the intake valves. It is very important that the spark plug is able to seal effectively so that fuel and air is not able to escape the cylinders. If the seal is not strong then the performance of the engine will decline as pressure in the cylinder is unable to reach its potential. The spark plugs connection allows it to be removed easily in case it needs to be changed.
- Piston: Performance influences the connection type of the piston because the piston must be able to smoothly move up and down the cylinder while maintaining a proper seal. The seal is very similar in nature to that of the intake valves and spark plug where pressure must be increased by compressing the fuel and air in the cylinder. The piston must be able to keep the fuel and air tightly sealing inside. Also, the piston must be able to move smoothly up and down the cylinder. If this can not be done then energy will be lost in the form of heat. The piston is designed to be removed easily allowing for it to be changed if needed.
- Cylinders: The most important performance influence of the cylinder is that is must be able to withhold heat. Done in part with the cooling subsystem, the cylinder should not allow for heat transfer. This adiabatic process will allow for the pressure and volume in the cylinder to both increase and decrease respectively. If heat escapes during this process then the compression will not be as effective as possible decreasing the performance of the engine.
- Crankshaft: The crankshaft may be the most important part of the power subsystem. It is greatly influenced by performance because it must be able to withstand a lot of stresses. The crankshaft must be sturdy because if it breaks then the motion of the cylinders will not be translated to rotational motion to move the vehicle. If the crankshaft is not designed to withstand the stresses and it breaks, then the engine will not run. As seen from our dissection this part is able to be removed fairly easily due to this fact.
- Oil Temperature Sensor: The oil temperature sensor plays a large role in the function of the engine by making sure it does not over heat. This is very important because the overall ability of the engine is drastically changed, even to the point where it can not function, if the temperature is not correct. The sensor is connected in a way that allows it to be removed fairly easily in case something goes wrong with it.
- Coolant Tube: The coolant tube is an important part that again keeps the engine running at the proper temperature. If the tube is not able to able circulate coolant throughout the engine then it will overheat. The coolant tube is subject to high temperatures and must be able to with stand them as well as other environmental and normal factors. The tube is able to be removed easily which allows it to be changed out if required.
The intake subsystems connection is influenced by performance because it must be able to provide fuel to the power subsystem and then seal itself. All parts of this system are connected physically to each other in order allow fuel to travel to the engine without leaking. The intake cam is connected to the push rod and rocker arm via the push rod seats and guides. Performance influenced this connection because by setting it up in this matter, the intake valve will open at an ideal time to let in the correct amount of fuel and air. The intake valve and spark plug are connected in a way that they form a seal so that the pressure in the cylinder will not leak out. By sealing this connection, the car can perform at its best by allowing for a full power stroke. The same is true for the connection of the exhaust subsystem. The valve must seal to prevent a pressure decease, the exhaust cam is connected to allow for the ideal opening of the exhaust valve and therefore let out exhaust at the correct time. The exhaust leaving the cylinders then all accumulates in the exhaust manifold. The manifold was bolted on in order to prevent exhaust from leaking out. The lubrication systems connection to the power subsystem was performance driven because the pistons must stay lubricated to reduce friction and therefore increase efficiency. The oil pump is connected to push the high pressure oil to places such as the piston and rotating bearings. The connection of the oil pan was connected to allow enough oil to be available. If enough was not available then the engine would experience too much friction. The oil filter is connected to keep the oil clean and therefore efficiently lubricate the engine. By connecting the lubrication system in this manor the engine can perform at its best. The cooling system, like the lubrication system, connects to the power supply to keep the engine from over heating. Performance influences this connection type because water must be able to travel throughout the engine to keep its temperature where it should be. The water pump, like the oil pump, pushes the water throughout the system. The coolant tube is used to carry the fluid that keeps the engines temperature down. This connection was performance driven because the tube will undergo high temperature so the connection must be able to experience a variety of temperatures as well.
Is there a reason for each subsystem placement?
There is a reason behind the placement of each subsystem. Placement can improve functionality of the engine as well as the total engine size. Certain subsystems, such as the valve train and camshaft, need to be connected for the engine to function properly. Other subsystems have similar reasoning as to be placed in a specific location. By analyzing which subsystems impact others, you can determine where the best location on the engine block for each part would be. The placement of subsystems can also impact the overall size of the engine. The engine must fit inside of the hood of a car among the other parts and systems that allow the car to work; therefore, it cannot be too large. The placement of the subsystems can place them closer to the overall engine. This could mean that some subsystems are attached to others that may not necessarily function together so that the engine will fit within the car.
Are there subsystems that cannot be adjacent?
As with any assembly of parts, there will be certain subsystems that cannot be placed adjacent to other subsystems. As a generic example, you would not want to place something adjacent to the cylinders that would cause impeded motion for it would make the engine less efficient. Subsystems perform specific functions that allow energy to be effectively transferred from one part of the engine to another. The placement of subsystems allows that transfer to happen quickly and effectively so that the engine may be efficient. If subsystems were to be placed in different locations, it could hinder the energy transfer and cause the engine to be inefficient, or even fail.