Group 2 - Gate 2
Gate 2: Product Dissection
Cause for Corrective Action
Our management plan worked perfectly for the engine dissection process. The project manager, Abhiram Rao, assigned tasks to the various group members according to their chosen roles listed in Gate 1. Abhiram and Emmanuel dissected the various components of the engine. Kenneth took pictures of the various parts, while Brian noted down the various steps in which the engine was dismantled. They also organized these parts into plastic bags according to the steps in which they were removed. William Janiak could not be present in the laboratory because he was at a conference in California.
Our work plan for this stage was to meet at the assigned lab times and work according to roles detailed in the management plans. We finished the dissection of the engine in two lab visits. One potential problem about distribution of tasks was that of speed of work. If group members dissecting the engine worked too quickly, the stenographers could miss some crucial dissection steps. However, our group overcame this problem by active communication between members. At such times, the group members working on dissection would stop work and help put parts away into plastic bags as the stenographers listed dissection steps and different parts of the engine were photographed. The plan worked flawlessly.
Lack of such communication in the future is another potential problem. Communication in the laboratory was adequate to get work done without major issues. Lack of communication outside the lab could result in project delays. To address this issue, we plan to coordinate group activities and keep track of the progress that each individual member has made through text messaging and email.
The following section discusses the dissection of our product in detail.
Table 1: Difficulty Scale
|1||Little effort required, screws to be removed very easily accessible, very basic tools used or part removed by hand|
|2||Moderate effort required, screws to be removed easily accessible, basic tools required|
|3||Moderate effort required, screws to be removed moderately difficult to access, basic tools required|
|4||Considerable effort required, screws to be removed difficult to access, specialized tools required|
|5||Excessive effort required, part to be removed heavy and screw accessibility moderately difficult to very difficult|
- Table 1: Difficulty Scale
Table 2: Steps to Dissect
|1||Remove intake manifold cover and throttle body||Removed 10 screws using a 10 mm wrench||1||Parts were meant to be removed, as it is the only way to access the balancing shaft and other components underneath|
|2||Remove alternator||Removed 2 screws using 10 mm wrench||1||We attempted to take this part apart further, but were unable to due to lack of screws and such to remove. We determined it was an alternator based on its location on the engine.
The fact that there were no visible screws on the surface of the component means that it is not meant to be taken apart, though it is meant to be removed from the engine so it can be replaced.
|3||Remove water intake pipe||Remove 2 screws using 10 mm wrench||1||This part probably should not have been removed, since the part underneath it was a valve that was placed (as opposed to fastened) in a specific position in order to work.|
|4||Remove water valve||No tools were required, could just be pulled out||1||Should not be removed under regular circumstances.|
|5||Remove performance sensor||Remove 2 screws using 10 mm wrench||1||Since it is a sensor, it should probably not be removed, as it would be used by a mechanic to ascertain an issue with the engine, and removing it could cause the sensor to fail.|
|6||Remove valve cover (2x)||Remove 6 bolts (3 each side) using 13 mm wrench||1||Definitely supposed to be removed, considering it is the only way to access the valve heads and pushrods|
|7||Remove distributer||No tools were required, could just be pulled out||1||Was attached with only one bolt, making it easy to remove, but it probably wouldn't be removed on a regular basis. It goes all the way inside the engine and down to the camshaft, making it an important part that must be kept in one spot.|
|8||Remove intake manifold||Remove 8 bolts using 13 mm wrench||3||Also removed another sensor on top with various wires connecting to various parts of the engine.
This part is supposed to be removed as it is the only way to gain access to the crank and cam shafts underneath.
|9||Remove serpentine belt wheels||Remove 4 bolts with 15 mm ratchet||3||Bolts are placed in awkward positions, making it somewhat difficult to remove, and making us think these parts aren't typically removed.|
|10||Remove water pump||Remove 4 screws using 14 mm wrench||3||To try and ascertain what the part was, we removed 6 screws from a cover on one end to reveal a rotor, leading us to believe it was some sort of turbine or pump. The location led us to believe it was a water pump.|
|11||Remove exhaust pipes (2x)||remove 8 bolts (4 each side) using 14 mm wrench||3||These could be removed for maintenance, and were one of the heavier parts we had removed up until this point.|
|12||Remove mounting bracket (2x)||Remove 3 bolts (1 missing, should be 2 each side) using 14 mm wrench||2||We determined these were some sort of bracket for placing the engine in the vehicle. After prying them apart (which we obviously were not supposed to do) we found a mass of rubber, leading us to believe it was used to lessen vibration.|
|13||Opened gear cover, cannot be removed yet, blocked by crankshaft||Removed 5 bolts using 14 mm wrench||3||The cover wasn't difficult to remove, but it cannot be taken off the engine as it is held in place by the crankshaft, which we hadn't removed yet.|
|14||Remove heads (6 each side)||Remove 18 screws with 15 mm wrench||4||Found that every other head had an extra bolt, with extra bolt situated closer to the front of the engine. We determined this was for alternating intake and outtake.
To gain access to the push-rods and cylinders, the heads need to be removed. Thus, it is definitely a part that is intended to be removed.
|15||Remove push-rods (6 each side)||Could just be pulled out||1||Would be removed for maintenance, especially since they aren't fastened in any way.|
|16||Remove cylinder cover (2x)||Remove 3 bolts (should be 4, one was missing) using 13 mm wrench||3||This part was not difficult to remove, though it should be held securely as it is placed on an angle, and will slide off onto the floor where it could cause injury (we found this out the hard way). Fortunately, no one was hurt.
This part has to be removable to gain access to the lifters below.
|17||Remove lifter cover and lifters (2 covers, 12 lifters)||Remove 4 bolts (2 each side) with 10 mm wrench, pull out lifters||2||The lifter cover is a small piece of plastic with 2 very obvious bolts, leading us to believe it is meant to be removed. The lifters themselves are only held down by the lifter cover, and, much like the push-rods, can just be pulled out by hand.|
|18||Remove oil pan and ring||Remove 6 bolts with 14 mm wrench||3||Must be removable based on there being several obvious screws and the fact that it covers up the entire bottom of the engine.|
|19||Remove oil filter||Remove 4 bolts with 10 mm wrench||2||The oil filter is made up of 2 parts, the filter itself and the inside gears which run the filtering mechanism.
The filter is a part that requires regular maintenance, and is easily accessible on the engine. This means it is a part that is meant to be removed and taken apart.
|20||Remove piston caps||Remove 8 screws using 16 mm wrench||4||These parts need to be disconnected to remove the pistons but, based on screw location, the pistons, as well as the caps, are not things that are supposed to be removed.|
|21||Disconnect pistons||Remove 6 nuts using 14 mm wrench||5||As stated previously, these should not be removed on a regular basis.|
|22||Remove Pistons||Remove 10 bolts using 11 mm wrench||5||After the caps and bolts were removed, all that was needed to remove the pistons from the cylinders was a little brute force, which was easier for some of the pistons and harder for others, based on the position in which the engine seized in.|
|23||Remove gear bolts||Remove 3 bolts using 13 mm wrench||3||Necessary to remove crankshaft and geartrain|
|24||Remove crankshaft and geartrain||Could just be removed without any extra work||2||Very heavy part that accidentally fell of the engine because we removed the last bolt while the engine was upside down. Otherwise would have been easy to remove.
We removed the chain and 2 gears from the geartrain, but could not disassemble further.
Due to the amount of parts that needed to be removed to get the crankshaft out, it is not a part that is intended to be removed by the average truck owner.
- Table 2: Dissection Steps
Connection of Subsystems
The engine has different types of connections between its subsystems. The ignition system starts the engine and is triggered by turning the ignition switch (user input). Electrical energy helps to start the components of the ignition system, which trigger the intake and combustion system. The intake and exhaust system is connected to the combustion system by mass flow. The mass is a mixture of air and gasoline for the intake system, and exhaust gases in case of the exhaust system. The sensor system is connected to the combustion system through signals of temperature and pressure. Its output is in the form of electrical energy, which is used to quantify the various engine function parameters like temperature and pressure and make them available to the user via gauges in the vehicle. The lubrication system is connected to the combustion system and the power transmission system by energy flow. The mechanical energy generated by friction in the moving parts of the engine can damage the engine. The lubricant absorbs this mechanical energy to a great extent and makes movement smooth inside the engine. The cooling system is also connected to the combustion system through energy flow. The thermal energy generated due to combustion of fuel is transferred to a coolant solution to keep the engine at manageable temperatures. The power transfer system harvests the power generated by combustion. This system is physically connected to the combustion system. The motion of the pistons moves the crankshaft. This is a component of the power transmission system, and the power goes to the wheels through a series of shafts, belts and gears.
The subsystems are connected to allow energy and mass flow from the input to the output of the engine. The conversion of one form of energy to the other in an engine takes place through a series of steps that occur within different subsystems. Energy and mass needs to be transferred from one subsystem to another. This makes connections between subsystems very important.
The engine primarily addresses economic and environmental concerns. The connections between subsystems have to be made robust, yet relatively inexpensive. However, the expense is not as important a factor as performance, and mass production of engine components helps keep the cost down. This makes the connections largely dependent on performance. The intake system is optimized to take in the correct ratio of gasoline to air, and send this mixture to the combustion system. The physical connection between the combustion system and the power transfer system is constructed to minimize energy losses due to friction. The lubrication system and the cooling system are connected to the combustion and power transmission systems in a way that allows maximum transfer of energy into these two subsystems.
The subsystems are arranged according to the function that the engine performs. The engine has to combust gasoline to produce energy, so the intake system is placed ahead of the combustion system. Also, due to a similar reason, the exhaust system is placed after the combustion system. The combustion system needs to be monitored, so the sensor system works in parallel with it. Also the lubrication system works in parallel with the combustion system and the physical connection between the combustion system and the power transfer system. The cooling system works parallel to subsystems that generate thermal energy.
The intake and exhaust portions cannot be immediately adjacent because the fuel needs to be combusted to generate exhaust. Similarly, intake and the power transmission system cannot be adjacent. Therefore, for the engine to perform its function, the subsystems need to be arranged in a specific order.
The functional model for our engine is depicted in the next section. The order of subsystem functions can be seen here.
- Image 25: Functional Model of the Engine