Gate 4 - Product Explanation
Cause for Corrective Action
Approaching the final steps in our project we have come across a few more challenges mainly all of which we have resolved. Working as a team thus far has made dealing with arising issues during our reassembly process much easier allowing for greater effeciency.
The reassembling of the pistons and its rings posed as the greatest challenge we faced during this process. Upon removal of the pistons during the disassembling process a few of the piston rings fell out of their slots; this made the reassembling difficult to not only reset the rings in their slots but to also replace the pistons themselves. To reslove these issues we did two things. First we were able to access a piston compressor in the laboratory which we used to place the rings back in position as we replaced the pistons. Second we had to make use of a small rubber mallet to actually replace the pistons themsleves; the presents of the compressor along with the angle they needed to be inserted made the reassembling difficult but working as a team this was able to be completed.
A second challenge that arose during reassembly dealt with the timing chain, this issue was actually foreseen based on the difficulty we had during its disassembling process. Due to the fact that we did not have access to the specialty tool, the pulley-puller, needed to remove the crank pulley replacing the timing chain was difficult. Without removing the pulley the timing chain couldn't just simply be placed on, therefore it had to be manouvered and worked on around the pulley and the timing chain cover which was also still assembeled because of being unable to disasseble the crank pulley.
The third and last challenge faced was also an expected one from the diassembling process. Because we didn't have all the bolts of the engine to begin with we knew that we obviously wouldn't have them during reassembly, therefore making it known that the engine would not be functional. This is an unresolved challenge that could only become resolved by purchasing the missing bolts for our engine.
Overall the reassembly process of the engine was not as complex as the disassembly process mainly because we were able to back track our previous process and all the steps and tools were already known. Although knowing the steps and tools saved us time we were still under a time contraint during this process. Because our engine was being shared with another group, we had to reassemble it as quickly as possible and as efficiently as we could so that they had the same opportunity and enough time to complete all the tasks necessary along with having to do so in the alotted lab hours available. Again with this challenge we used our teamworking skills and formed somewhat of an assembly line having the next component ready when the previous one was complete. Working together as always allowed our tasks to not only be complete and efficient but to do so in a timely manner.
Here is our groups Product Reassembly Difficulty Scale (Chart 1). This illustrates the difficulty of each of the following Reassembly Steps.
|1||Very simple, requires minimal effort and time|
|2||Simple but may require some effort|
|3||Fairly simple but requires some effort and time|
|4||Complex and requires effort and time|
|5||Complex and requires excessive effort and time|
Chart 1: Difficulty Scale
Reassembly of the Rotating Assembly
Pistons and Connecting Rods (Difficulty 4)
After we put the camshaft into place we put the pistons and connecting rods back into its original cylinders to match the boring. To do so we used a piston compressor to compress the pistons and piston rings. Then we took a rubber mallet and pushed the piston into position and undid the piston compressor. It has a difficulty of 4 because it requires a good amount of effort and the use of specialty tools. During actual assembly process this may be done after the crankshaft and main bearing caps is installed and with the rod bearing and connecting rod end caps because with tight piston rings this motion could be easily automated and done rapidly. This step was different from the dis-assembly because we had to use a piston compressor to put the pistons back into place instead of just hitting them back into place.
Crankshaft (Difficulty 3)
To put the crankshaft back into place we had to make sure all the connecting rods were in a position where the crankshaft would not hit it when placed. Next we to crankshaft and put it in its ridges, during which we had to move a few of the connecting rods. After the crank was in place we put the connecting rods tight to the crankshaft for attaching the rod end caps Because of the during-installation moving of other components, installation of the crankshaft has a difficulty of 3. During an assembly proses the crankshaft would most likely be the first component installed on the engine block in a preset position to make the installation of the connecting rods and bearing caps easier. this step was almost the came as the dis-assembly except that we had to position the connecting rods.
Main Bearing Caps and Main Bearings (Difficulty 2)
To install the Main Bearing cap we first had to put the main bearings in place on the cap, and then we put all four of the main bearing caps in place and tightened them down with (8) 14mm bolts. This step is given a difficulty of 2 because it is simplicity and the number of bolts. In the assembly proses this would be done after the crankshaft to help hold in place. This step was just the dis-assembly in reverse.
Removal of Connecting Rod End Caps and Rod Bearings (Difficulty: 2)
After we put the main bearing caps in place we put the rod bearings back into the connecting rod end caps then we put them on each of the connecting rods and tightened the (12) 14mm nuts on to the connecting rod, two on each connecting rod end caps. This step has a difficulty rating of 2 for its simplicity and number of nuts. During a manufacturing proses this would be done after the pistons were installed to hold them in place. Just like the main bearing caps, to do this step we just followed out dis-assembly process in reverse.
Internal Oiling System (Difficulty: 1)
To put the Oiling system back in place all we had to do is put in (2) 16mm bolts to reattach the oil pump to the block, which is why this step has a difficulty of 1. During an assembly proses this would be done after the crankshaft and pistons are in place and are secured. To put this component back on we just followed out dis-assembly instructions backwards.
Oil Pan (Difficulty: 3)
After we put the internal oiling system back in place we put the oil pan over most of the parts of the rotating assembly. This required that we lift the oil pan above the internal oiling system then put (6) of the (10) 13mm bolts we have back in place. This has a difficulty of 3 because of how heavy the oil pan is and the fact you have to lift it up above the internal oiling system. During assemble this was put on after the internal oiling system. We put this component back on by doing out dis-assembly instructions in reverse.
External Oiling System (Difficulty: 2)
Actually putting the external oiling system was easy, simply putting (2) 10mm bolts back into place, but after that we had to rotate the engine 180 degrees to get it back into its original position . The reason the difficulty is a 2 is because it takes quite a bit of force. During assembly this would put on after the oil pan, but it may or may not be turned. This component was also put back on by taking the dis-assembly instructions and doing it in reverse.
Reassembly of the Timing System
Camshaft (difficulty: 1)
The first component we put back in the engine is the camshaft, we put this back into the engine simply by pushing into the camshaft housing then putting on (2) T30 bolts, which is why this step has a difficulty of 1. During the assembly proses this would be done before the rotating assembly is installed. To put this component back into position we followed the dis-assembly instructions backwards.
Timing Gears (Difficulty: 3)
In order to get the secondary camshaft gear back on we had to line up all three with the holes on the camshaft then put on (3) 14mm bolts, then do the same for the primary camshaft gear then put on (3) mire 14mm bolts. This step has a difficulty of 3 because lining up the holes can be a little hard. During manufacturing this would be done after the camshaft is in installed to hold it in place. This step was similar to the dis-assembly but we had to make sure the holes on the gears lined up with the rods on the end of the camshaft.
Timing Chain (Difficulty: 5)
Reseating the timing chain was one of the hardest steps of the reassembly because we had to get the chain to reseat which was both time consuming and took a lot of effort which is why this step has a difficulty of 5. During an assembly they my seat the chain and install the primary camshaft gear in the same step. This step was just as hard to assemble as it was to disassemble so we simple followed our dis-assembly instructions backwards.
Timing Chain Cover (Difficulty: 2)
With the timing system in place, the next step was to put the timing chain cover back in place then tighten (8) 10mm bolts. After that we put the outer crankshaft belt pulley in place and tightened the (3) 13mm bolts. This step was fairly easy not requiring much skill which is why it has a difficulty rating of 2. During assembly this would have to be done after the rotating assembly and the rest of the timing system was assembled. This step followed the exact same instructions as the dis-assembly.
Reassembly of the Valve Train
Cylinder Head (Difficulty: 3)
The cylinder head is the first item to be put back onto the engine in the valve train. When originally assembling and reassembling the cylinder head a gasket must be placed in between the head and engine block to eliminate the leakage of fluids and vapors as well as make a tight seal in between the two parts in order to work properly. We used a 3/8 inch socket wrench to tighten the seven 13 mm head bolts attaching the cylinder head to the engine block. The outer two head bolts are shorter than the other five and it is important that they are placed in the correct place to secure the cylinder head properly. Due to the heavy weight of the head, a partner must hold it in place while securing the bolts. This is why the difficulty given to this process is 3.The assembly was performed almost exactly the same as the disassembly making it fairly simple to do.
Exhaust Manifold (Difficulty: 2)
The installation of the exhaust manifold was slightly easier to reassemble then it was to disassemble but was similar. So this has a difficulty of 2. For this process we used a 14 mm socket wrench to tighten the 6 bolts connecting the exhaust manifold to the cylinder head. This had to be done twice, once on each side, being that there are two exhaust manifolds on the engine block. It helped when one person was holding the manifold in place being that it is fairly heavy. If we had the intention of running the engine, it is necessary to put gaskets in between the exhaust manifolds and the engine block to eliminate leaks. This would have been done in the original assembly of the engine.
Push Rods (Difficulty: 1)
The push rods are very simple to reassemble and it is similar to the way it was disassembled. Place each one, six on each cylinder head (12 in all), in its respective slot opposite the valve spring. The hole which the push rod is placed in should go all the way down to the lifter which is connected to the camshaft. This does not require any tools and is extremely simple which is why it is given a difficulty of 1. This is how the push rods would have been originally installed.
Rocker Arms (Difficulty: 3)
For the reassembly of the rocker arms we used a 3/8 inch socket wrench to tighten the bolts on top each of the rocker arms. The bolt seat is placed in first with the bolt following so that the bolt has a flat surface to sit on. But you must check first that the end with the rounded indentation is placed on top of the push rod so that the valves will open and close properly. This is how it would have been assembled in the factory. We found that the reassembly of the rocker arms was the same but much easier than the disassembly of them so we gave it a difficulty of 3. It still took a fair amount of time because of the six rocker arms (12 in all) on each of the two cylinder heads but the process was easier.
Valve Cover (Difficulty: 1)
The two valve covers are the last things put back onto the cylinder heads. The way this was done is the same as the disassembly and same to the way it was assembled in the factory. A 3/8 inch socket wrench must be used to tighten the three bolts on each cover (six in all). This step was very easy to do because the valve covers sat in place and the bolts only had to be tightened. It was not time consuming or difficult which is why we gave it a difficulty of 1.
Reassembly of the Air Intake System
Intake Manifold (Difficulty: 2)
The first thing that must be put onto the engine in this system is the intake manifold. This is because everything else sits on top of it. The manifold sits into place on the engine block and must be tightened into place with eight 13 mm bolts using a 3/8 inch socket wrench. If the engine was intended to run, a gasket must be placed in between the engine block and the intake manifold to eliminate leaks and create a secure seal for the manifold. In the original assembly of this piece, there would have been a gasket placed in between the manifold and the engine block as stated above and is made so that it can be taken off and switched but the manifold itself cannot be disassembled any further because of it being made of one solid piece. The whole process was very simple and almost exactly executed as the disassembly but due to the weight of the manifold, we gave it a difficulty of 2.
Fuel Injection Subsystem (Difficulty: Unknown)
Because we were not able to disassemble this piece during the dissection, it was not necessary for us to reassemble this piece that is why it is given an unknown difficulty. We were not able to disassemble the fuel injection subsystem because we were not able to reach the bolt that had to be loosened with the tools we had.
Distributor (Difficulty: 1)
This installation of the distributor is very simple. Place the thin end down into the slot in the back of the intake manifold. It is then secured by a 10 mm bolt using a 10 mm wrench. It cannot be tighten with a socket wrench because of clearance issues. Originally in the factory, the distributor would have been lubricated at the end where the gears are so that friction is reduced but since we are not running the engine this step is not needed. Because of the ease of reassembly we gave it a difficulty rating of 1. It was also just as easy to disassemble this piece as it was to put back together because we followed the same procedure.
Manifold Cover (Difficulty: 3)
When disassembling the manifold cover, we discovered that the cover was missing four of the ten bolts needed to fully secure the manifold cover down. Even though we could not find the missing bolts it was still very secure to the intake manifold but when the engine was originally manufactured, it had all ten bolts as well as the cover being able to be removed when needed. When tightening the ten 10 mm bolts, use a 10 mm wrench to tighten them down. The cover should fit right into place matching up with the holes for the bolts to go into. Next the fuel injectors can be installed into the fuel inlet passages on the intake manifold by simply pushing them until they click into place. Because of the time spent to secure the bolts and install the fuel injectors, we gave this process a difficulty of 3. In the original assembly of this product, it would have had all the necessary bolts but all in all the same as we did here. The assembly was also the same as the disassembly in the way that we just loosened the bolts and took it off.
Throttle Body (Difficulty: 1)
This would be the last item put onto the engine in our assembly, as well as the original factory assembly which is the same as we did here. The throttle body is made to be able to come off in order to service the engine in the event of something going wrong inside of the engine or cylinder heads. It attaches to the manifold cover with three 10 mm bolts which can be tightened with a 10 mm socket wrench. Place the throttle body on the cover in the appropriate slot and secure it with the three bolts in each corner (one corner does not have a bolt). Also, a gasket would have been placed in between the throttle body and the intake manifold in the original assembly. So because this is a very simple step it is given a difficulty level of 1. It was very simple to disassemble and to assemble being that there are only three bolts that attach it to the manifold cover which was the same as the disassembly process.
Reassembly of the Cooling System
Electric Water Sensor (Difficulty: 1)
To install the electric water sensor all you do is put in place and then tighten (2) 10mm bolts which is why this step has a difficulty of 1. This would be one of the final steps of an assembly and may be done by hand. Putting this component back we just followed the dis-assembly instructions backwards.
Thermostat (Difficulty: 1)
Just like the electric water sensor, to install the thermostat you simply just put it in place and tighten (2) 10 mm bolts so this step also has a difficulty 1. Also like the electric water sensor, this would be one of the last components to be installed on the engine and may be done by hand. This step was done by doing the dis-assembly process in reverse.
Water Pump (Difficulty: 2)
In order to install the water pump we into place and hold up while (4) 14mm bolts are tightened by another group member. This step has a difficulty of 2 because the water pump is slightly heavy and it needs to be held till at least 2 of the bolts are tightened. During an assembly this could be done any time after the timing chain cover is put in place. This step was similar to the disassemble except the we had to hold the water pump to line it up with the bolt holes.
The GM Vortec 4300 was originally designed in the 1980's for use in larger vans, SUVs, and pickup trucks. Since this engine is more than twenty years old, there is new technology available that would be able to address the downfalls of the Vortec 4300 engine. Similar vehicles today produce more power, with a higher displacement engine, while returning better fuel economy. Revisions could be made to the Vortec 4300 to improve its power output as well as fuel economy.
The intake system could be revised to accommodate a forced induction system. Forced induction allows internal combustion engines to create more power than similar sized naturally aspirated engines. A turbocharger uses the force of the exhaust gases to spin a turbine which forces air into the intake of the engine. This allows for more power to be made since more air will be present in the cylinder during combustion.
Turbocharged vehicles have been available to the general population for over two decades, including the GM built Syclone and Typhoon. These two vehicles were built in limited production numbers and were powered by a turbocharged Vortec 4300. The single turbo increased the power output greatly while retaining the fuel economy of the naturally aspirated engine. Ford is also using this idea on the current model lineup with an option EcoBoost engine available on some models. Ecoboost uses forced induction combined with direct injection and is becoming popular with the general public. It has made an impact on vehicles by providing great benefits with few negative aspects. As it becomes more widely used it will change the automotive field completely. Similar to the Syclone and Typhoon, the Ford Taurus SHO uses forced induction to create competitive performance figures, but not improved fuel efficiency statistics. A naturally aspirated engine needed to produce the same amount of power as the turbocharged 3.5 liter would have to have a much higher displacement, resulting in worse fuel efficiency figures. Some vehicles use forced induction for improved fuel efficiency. Visiting the Ford website will show the Ford F150 is a great example of this. It is offered with an optional 3.5 liter six cylinder engine paired with turbochargers to make the same amount of power as the much larger eight cylinder engine. This allows the consumer to use less fuel, but perform the same task. The Vortec 4300 was available in some pickup trucks as the smallest, least powerful, but most fuel efficient option. The use of forced induction would allow the public to use the turbocharged 4.3 liter six cylinder engine as opposed to a lager eight cylinder engine that was also an option at the time. This would allow the consumer to perform their necessary tasks while returning an improved fuel efficiency.
A forced induction setup would address societal, environmental, and economical concerns. The increased power would considered a societal factor, since it has the potential to appeal to a large audience. The better fuel efficiency, in comparison to a larger engine with similar power, would be considered an environmental factor. The vehicle will send a smaller amount of harmful emissions in to the environment. The improved fuel efficiency would also result in less fuel consumption, decreasing the operating cost for the consumer.
One major design revision to the system level of our Vortec 4300 is the addition of a Camshaft Phaser into the Valvetrain System. This proposed design revision is the product of the desire to increase overall engine power, while also increasing efficiency of the engine. The need for these changes come from the consideration of societal and environmental design factors, and therefore both of these will be increased from the addition of a camshaft phaser into the Vortec 4300.
The engine's original design is a fixed camshaft position. This means that the engines camshaft timing is constant, and the camshaft timing contributes to the high-end engine power versus low end engine torque and fuel economy. Therefore if the engine's camshaft timing can be variable, the engine can achieve superior low end toque, fuel economy, as well as high-end power. The camshaft phaser allows this to be accomplished by changing the orientation of the camshaft as engine oil pressure increases. The increase in engine oil pressure is an effect of increased engine speed, and therefore the camshaft can be timed for optimal fuel economy and torque at low speed, then change linearly to a setting of optimal power at a higher engine speed.
Having the engine capable of effectively changing its' priorities is very beneficial for multiple reasons, illustrated by the design considerations. Having increased fuel efficiency at normal, low speed operating conditions shows how environmental design factors are used. While also having increased power available at higher engine speeds portrays how societal design considerations of the desire for increased power are taken into account. The camshaft phaser assembly is in all 4 major pieces, and it replaces the camshaft sprocket which is one piece, therefore only adding 3 additional pieces to the engine, and only about half of a pound of added rotating mass. Therefore the effects of the added mass negligible however the benefits are substantial. Global design considerations also come into play because the camshaft phaser would be the same exact piece as used in the LS engine series family, therefore absolutely no added engineering would need to go into the production/design of the part. This is also attributed to economic design considerations because the increase in the cost of the engine will be very small, just the cost price of the camshaft phaser unit. Therefore the price point would stay at almost exactly the same, and therefore the target audience would not be affected. If any change in the customer base were to occur, it would only attract more consumers for the increased fuel efficiency. Overall the camshaft phaser is an extremely beneficial tool to extract increased performance from the engine, while also increasing overall efficiency, all while changing a very limited amount of parts with no added design.
Another system level design revision our group decided upon was the change of fuel injection method from port fuel injection to direct fuel injection. This system change is due to the consideration of environmental and economical factors applied to the design of the fuel injection system. A direct fuel injection system will increase the combustion efficiency of the engine while also allowing for an automatic start/stop ability of the engine to save fuel when the engine is not being used to move the vehicle.
A direct injection fuel system injects fuel directly into the combustion chamber during the compression stroke, as opposed to injected fuel into the intake ports. This is beneficial to the engine for a number of reasons. Direct injection disperses fuel much more evenly into the cylinder than conventional fuel injection. This leads to a more complete burn of the fuel, and therefore a fuller, more powerful combustion, meaning that less fuel can be used to make the exact same amount of engine power versus conventional injection. Also with direct injection, pre-detonation of the air fuel mixture is much less likely, allowing for increased engine compression ratio or increased forced induction capabilities. Another extreme benefit of a direct injection system is the integration of an automatic start stop function of the engine. When the engine is at idle, say for a stop light or short period of waiting, the engine can shut itself off saving fuel, then start again when needed. Instead of using the starter motor to start the engine, which is very stressful on the engine, the engine injects fuel into the cylinder with closed valves, ignites whatever mixture is in that cylinder, which then allows for normal operation of the engine. This cannot be achieved with conventional fuel injection because there is no force to pull the fuel into the cylinder, but with direct injection, fuel goes directly into the cylinder.
Mazda Motor Corporation attempted to incorporate this design into their vehicles but was unsuccessful with developing an efficient direct injection design. This is where General Motors would also benefit from this design revision, having already pioneered direct injection, and mastering it in the LNF/LDK/LHU engine family. Therefore again already having the technology, minimal research would be required to adapt this system to a Vortec 4300 platform. However the actual costs of the direct injection system, along with the additional engine computer capabilities needed for this design revision would be expensive. Therefore this could be added to the engine, and included in the same vehicles as a cost-option, attracting customers seeking far superior fuel economy while retaining the previously established customer base. From this design revision, the environmental considerations are very obvious, due to the direct injection system directly increasing efficiency and lowering emissions. While also economic design considerations are involved in the effort to decrease fuel consumption, while also sharing technology from the companies previously established successes. Therefore as stated the benefits of the conversion to a direct injection fuel system, along with the automatic start stop function dramatically increase engine efficiency, decrease emissions, and decrease fuel consumption.