Group 11 -GM V-6 Engine Gate4
Cause for Corrective Action
Gate 4 went quite smoothly for the group as there were no real conflicts that arose during the process of completing the gate. The reassembly of the engine was completed approximately one week before the due date on the gate. This gave the group members plenty of time to complete their respective assignments before the due date. Although the due date had been pushed back from its original date, the early completion of the reassembly is a testament to the smooth operation of the group during the final gate.
The smooth operation with Group 11 was also assisted by the much improved communication between groups 10 and 11. In Gate number two, both groups cited inter-group communication as a major source of frustration and difficulty. After Gate 2, it was stated that the project managers would sit down and discuss the plans for the rest of the project. Gate 3 did not require a great deal of interaction between groups 10 and 11, so the problem really was not fully resolved. Almost immediately after Gate 3 was completed, the two groups discussed their plans for the reassembly. From this discussion, the plan for reassembly was laid out and everything went smoothly from that point.
When considering the difficulty of the reassembly process of the Vortec 4300 LG3, the question how many forms of difficulty there are must be considered. When examining this, it became apparent that only one category for difficulty would not adequately describe the level of difficulty of reassembling the motor. Therefore, the difficulty assessment has divided into two separate categories. The first category is physical difficulty. This category encompasses the level of difficulty to physically perform the task. The physical difficulty would include the weight of the part, the difficulty of getting the part into place, the difficulty of lining up holes, and more. The second category is technical difficulty. This category encompasses how difficult it is to figure out how to perform the task. This includes how difficult the tools are to use, how obvious it is how the tools are used, and how obvious it is to reinstall the part in that manner.
Also vitally important to the successful creation of a scale of difficulty, is knowing who is going to be performing this task. In this case, it was decided that the scale of difficulty would be written for an individual who had not seen the engine before and has only a minor amount of technical knowledge. This is adequate because it is unlikely that anyone without the knowledge of what ratchet or socket is will try to reassemble this piece of machinery.
Table 1: Physical Difficulty Rating
Table 2: Technical Difficulty Rating
Assembly Compared to Reassembly
The reassembly of the engine was quite similar to the reverse of the assembly process. Some of the steps were done in a slightly different order compared to the disassembly. This was not done not due to necessity, but rather due to convenience. The exact reverse order of the disassembly process would have been an acceptable way in which to reassemble this engine. The only real differences would have been the necessity to use a piston ring compressor in order to reinsert the pistons and the necessity to already have the timing chain on the sprockets on the cam and balancing shaft before installing. The big difference between the reassembly process used for Gate 4 and the disassembly process used for Gate 2 was where the oil pump and oil pan were dealt with. In the disassembly, they were removed before the camshaft, balancing shaft, and timing chain. In the reassembly, the oil pump was reinstalled right after the bearings were installed. The reason for this was sheer convenience. The motor was already turned upside down which allowed for easy access to the area where the oil pump was located. Afterwards, the pistons were reinstalled and the retainers were bolted down again, and then the oil pan was put back on the motor. The reason for this was again convenience. From the completion of the disassembly, the group knew that there was not anything else that needed to be reinstalled before the oil pan was put back on the motor. Since this was the last time the motor needed to be upside down, the oil pan was put back on at that point rather than waiting and then having to turn the motor upside down again. This slight alteration in the process saved the group some difficulty in the reassembly. The tools needed for the reassembly process were the exact same as were needed for the disassembly. The only other tool needed was a piston ring compressor.
The tools needed were as follows:
- Piston Ring Compressor
- 9/16in socket
- 3/8in drive ratchet
- 10mm socket
- 1/2in socket
- T30 socket
- 1/2in wrench
As stated earlier, the reassembly process went smoothly, however some difficulties were encountered. The greatest difficulty encountered was the installation of the timing chain and accompanying sprocket. The reason for the difficulty was the way in which the sprocket needed to be installed. The sprocket was quite difficult to align properly on the motor. If it was left in its slightly offset alignment, it could have done serious damage to the timing chain. It took several attempts and some difficulty but finally the sprocket was successfully installed in the proper alignment. Another serious difficulty the group encountered was the reinstallation of the heads. The issue here was alignment of the push rods sitting in the engine block with the proper holes in the head. This again took several attempts and the eventual use of a second person in order to get the push rods into the holes in the head. Eventually these two difficulties were overcome and the reassembly went smoothly from that point.
The crankshaft, with flywheel attached, is put back into the engine block. In order to do this, the engine must be turned upside down. The crankshaft can then be placed back in the motor with the same orientation as when it was removed from the engine block. This is difficult to do since, since the crankshaft fits so tightly inside of the block. No tools are necessary to do this. The crankshaft is a very heavy component which is quite awkward to get into the proper position. As a result, the physical difficulty of the installation was rated as a 4. It is quite obvious where the crankshaft is to be installed and the process needed. Therefore, the technical difficulty was rated as a 1.
The bearing retainers are placed back into the motor and bolted on to the engine block in order to hold the crankshaft in place. There are four of them and each has two 5/8in bolts. They are fairly easy to install and will effectively hold the crankshaft in the block. The bolts must be adequately tightened in order to ensure that the bearing due not become loosely fastened to the block. A 5/8in socket with a 3/8in drive ratchet is needed to complete this task. The bearing retainers are very lightweight and easy to install. Therefore the physical difficulty was rated as a 1. Since a 5/9in socket and a ratchet were needed and these tools tools are highly intuitive and obvious how to use, the technical difficulty was rated as a 2.
The oil pump is reinstalled in the motor. The oil pump is placed at the back of the motor and three 5/8in bolts are used to affix it in place. A 5/8in socket and a 3/8in drive ratchet are needed to complete this task. Since the oil pump is quite lightweight and easy to install, the physical difficulty is rated as a 1. Since only a ratchet and a 5/8in socket are needed, the technical difficulty was rated as a 2.
The pistons are reinserted into the engine. In order to do this, a piston ring compressor must be used. The piston is inserted in the ring compressor and then the compressor is tightened in order to force the rings back inside of the piston. The piston is then tapped out of the compressor and back into the cylinder well. The piston must be aligned so that it sits correctly on the crankshaft. The only tool needed to complete this task is a piston ring compressor. Since the piston is lightweight and easy to install, the physical difficulty was rated as a 1. Since a piston ring compressor is needed and this tool is unfamiliar to many people, the technical difficulty is rated as a 4.
The retainers are placed back on the piston. Then, two 9/16in bolts are used to affix the connecting rods and retainers. There are six connecting rods and six retainers. A 9/16in socket and a 5/8in drive ratchet are necessary to complete this task. Since the retainers are lightweight and easy to install, the physical difficulty was rated as a one. It is very obvious which tools are needed and how they are to be used. As a result, the technical difficulty is rated as a 2.
The oil pan is then placed back onto the motor. The pan is then affixed by ten 1/2in bolts. The bolts must be tightened properly. A 1/2in socket and a 3/8in drive ratchet are necessary for the successful completion of this task. Since the oil pan is lightweight and easy to install, the physical difficulty is rated as a 1. Since it is obvious that a ratchet and a socket are needed to install the part, the technical difficulty is rated as a 2.
The cam shaft is then put back inside the motor. This is done by simply sliding the cam shaft with the gears pointed toward the rear of the engine through the hole it was taken out of originally. The cam will slide right back into place, but make sure that is goes as far back as possible in order to ensure that it goes into the fitting for it in the rear of the engine. No tools are necessary to put it back in place and for the time being, the cam will just sit in place. Since the cam shaft is lightweight and easy to install, the physical difficulty is rated as a one. Since no tools are needed and it is obvious how to install it, the technical difficulty was rated as a 1.
The cam retainer is then reinstalled. The cam retainer is located at the very front of the motor and two Torex T-30 bolts must be reinstalled in order to hold it in place. The proper installation of this part will ensure that the cam shaft is held in place. A T30 socket and a 3/8in drive ratchet are needed to complete this task. Since the cam retainer is lightweight and easy to install, the physical difficulty is rated as a 1. Since a specialized tool that a technical novice would not know is needed, the technical difficulty is rated as a 4.
The balancing shaft is then reinstalled. The balancing shaft is slid through the hole it originally came out of at the very top of the engine block. Once in place, two T-30 Torex bolts must be tightened on the balancing shaft retainer in order to hold it in place. A T30 socket and a ratchet with a 3/8in drive are necessary in order to complete this task. Since the balancing shaft is lightweight and easy to install, the physical difficulty is rated as a 1. The technical difficulty is rated as a 4 since a specialized tool is needed for the installation of this part.
The sprocket attached to the camshaft, along with the timing chain, is then reinstalled. In order to do this, the timing chain must be put on to the sprocket. The sprocket must be put approximately in place on the cam shaft, and the timing chain must go onto the sprocket on the balancing shaft as well. Once the timing chain is on the sprocket attached to the balancing shaft, the sprocket is put on the cam shaft. A small rod sticks off of the cam shaft retainer that goes through a hole on the sprocket. Once in place, three 9/16 in bolts must be tightened on the sprocket. This will hold the sprocket in place and prevent the timing chain from coming off the engine. A 9/16in socket and a 3/8in drive ratchet are needed in order to complete this task. Since this part is very difficult to align properly on the motor, the physical difficult is rated a 4. The technical difficulty is rated as a 2 since only a ratchet and a socket are needed to install the part.
The timing chain cover is then reinstalled on the front of the motor. It is placed over the timing chain and then affixed with six 1/2in bolts. A 1/2in socket with a 3/8in drive is necessary in order to complete this task. Since the cover is lightweight and easy to install, the physical difficulty was rated as a 1. Since a ratchet and a socket were needed to install the part, the technical difficulty was rated as a 2.
The harmonic balancer is then installed on the front of the motor. This is done lining up the key way on the crankshaft with the slot on the harmonic balancer. Once it is aligned, the harmonic balancer is tapped into place with a hammer. The only tool necessary in order to complete this task is a hammer. The physical difficulty was rated as a 2 because it required a small amount of force to reinstall the harmonic balancer. The technical difficulty was rated as a 3 since it was not very obvious how to reinstall the part.
The serpentine pulley is then installed on the front of the motor. It is placed onto the harmonic balancer and then bolted in place with three 9/16in bolts. A 9/16in socket with a 3/8in drive ratchet is necessary in order to complete this task. The physical difficulty was rated as a 1 since the pulley is lightweight and easy to install. The technical difficulty was rated as a 2 since a 9/16in socket and a ratchet were needed.
The water pump is then installed on the front of the motor. The water pump sits over the timing chain cover and directly above the harmonic balancer. It is bolted in place by four 9/16in bolts. A 9/16in socket and a 3/8 drive ratchet is necessary in order to complete this task. The physical difficulty was rated as a 2 since the component is fairly lightweight but must be held up for a fairly long period of time in order to install the part. The technical difficulty was rated as a 2 because a ratchet and 9/16in socket were needed.
Each of the twelve rockers was then installed inside of the heads. The rockers were affixed in position by a 1/2in nut. When placing the rocker back inside the head, the roller inside the rocker must be in place. Once the rollers are in place, the rockers can be tightened down. A 1/2in socket with a 3/8in drive ratchet is necessary in order to complete this task. The physical difficulty was rated as a 1 because the rocker is very lightweight and easy to install. The technical diffculty is rated as a 2 since a ratchet and 1/2in socket are needed.
The twelve lifters are then placed back inside the motor. These are placed into holes in the top of the engine block and sit on the camshaft. No tools are required in order to accomplish this task. The physical difficulty is rated as 1 because the part is lightweight and easy to install. The technical difficulty is rated as a 1 since no tools were needed for this process.
The push rods were then placed back inside the motor. All twelve push rods are put through holes in the top of the motor and are then slid into place on the lifters. No tools are required to install the push rods. The physical and technical difficulty of this step is rated at a 1 because of the overall ease.
The heads are then installed. The heads sit at the very top of the engine block on the each side of the motor. The push rods must be aligned through the holes in the heads. This required one person lowering the head into position and another person aligning the push rods in the proper place. Once the rods are aligned with the appropriate holds in the heads, the heads can be lowered onto the engine block. A small rod sticks off of the engine block and must be aligned and placed into the appropriate hole on the heads. Once properly aligned, the heads can be affixed to the block using twelve 9/16in bolts. A 9/16in socket with a 3/8in drive ratchet is necessary in order to complete this task. The physical difficulty of this step is rated at a 5 due to the weight of the part and the need for a second person to align the push rods. The technical difficulty is rated at a 2 due to the easily identifiable bolts and tools needed.
The intake manifold is then installed on the top of the motor. The intake manifold is lowered down onto the motor at then sits in place. It is then held in place by installing eight 1/2in bolts. A 1/2in socket with a 3/8in drive ratchet is necessary in order to complete this task. The physical difficulty of this step is rated at a 2 because the part is fairly heavy and requires that the bolt holes be lined up. The technical difficulty is rated at a 2 because of the easily distinguishable tools needed to complete the task.
The valve covers are then reinstalled on the heads. This is done by place the plastic cover over the valve train on the heads and then aligning the holes in the valve cover with the appropriate holes in the engine block. Two 1/2in bolts are then attached to hold the valve cover in place. A 1/2in socket with a 3/8in drive ratchet is necessary in order to complete this task. The physical difficulty of this step is rated at a 1 due to the lightweight of the covers. The technical difficulty is rated at a 2 as the tools needed are easy to identify.
The exhaust manifolds were then reinstalled on the sides of the engine block. These are aligned with the appropriate holes in the engine block and are then affixed to the engine block by six 9/16in bolts. A 9/16in socket with a 3/8in drive ratchet is necessary in order to complete this task. The physical difficulty of this step is rated at a 3 because of the weight of the part and the strength needed to hold the part in place to insert the bolts. However, technical difficulty of the step is rated at a 2 because it was easy to distinguish the tools needed to complete the assembly.
The intake manifold cover is then reinstalled. It is lowered into place on the top of the intake manifold. Six 10mm bolts must then be installed in order to hold the cover in place. A 10mm socket with a 3/8in drive is necessary in order to complete this task. The physical difficulty of this step is rated at a 2 because although the part is lightweight, some alignment was needed to ensure the bolt holes lined up and the cover fit properly. The technical difficulty of this step is a 2 as the tools needed were easily identifiable.
The distributor is then installed on the top of the motor in the very back of the engine block. It is simply lowered into position and place down the hole in the engine block. A 1/2in bolt is used to hold the distributor in place on the top of the engine block. A 1/2in wrench is necessary in order to complete this task. The physical difficulty of this step is rated at a 1 due to the fact the distributor was simple placed in the hole without and trouble. The technical difficulty of this step is a 2 as the tools needed were easily identifiable.
The throttle body is then installed on the top of the intake manifold. It is simply lowered into place and then bolted down by three 10mm bolts. A 10mm socket with a 3/8in drive is needed in order to complete this task. The physical difficulty of this step is rated at a 2 because although the part is lightweight, some alignment was needed to ensure the bolt holes lined up and the cover fit properly. The technical difficulty of this step is a 2 as the tools needed were easily identifiable.
Active Fuel Management
As gas prices continue to rise, fuel-efficient vehicles become more and more appealing to consumers. The addition of Active Fuel Management to the motor would significantly improve its fuel economy. This would help address the economic, global and societal concerns of the consumer and gas prices. Active Fuel Management is the General Motors technology that allows a V-6 or a V-8 motor to operate as an Inline three cylinder or Inline four cylinder motor under certain driving conditions. According to the Environmental Protection Agency, the vehicle equipped with this Active Fuel Management can expect to improve its fuel mileage by about six to eight percent. Clearly, this is a large improvement in fuel mileage and has been used in truck and SUV motors. Specifically the 2010 Yukon XL, 2010 Cadillac Escalade, and 2011 Chevrolet Tahoe come equipped with Active Fuel Management and do so effectively. The addition of this technology also addresses the large societal factor of the United States’ consumption of oil. Congress has enacted legislation mandating that all companies making vehicles that are “manufactured for sale in the United States” meet the Corporate Average Fuel Economy of thirty-five miles to the gallon. Previously, small trucks and SUVs have been exempt from the Corporate Average Fuel Efficiency (CAFÉ) legislation; however as of 2016, they are included. Therefore it is vitally important for a small truck motor like the Vortec 4300 LG3 to meet the new standards and to address the societal concern of over consumption of gasoline.
Active Fuel Management works on the idea that a powerful motor is inefficient under normal highway driving conditions. Therefore, it is possible to reduce the number of cylinders that are functioning and still keep the vehicle operating at an acceptable level. The vehicle can still operate the electrical devices it is equipped maintain its speed while the drive is unaware that a portion of the cylinders are not operating. With the only real notable change is the amount of fuel being consumed there are really negative aspects of such a system. If more power is needed, the inactive cylinders readily reactivate to provide the additional power. This is the major advantage of this technology, since the motor still would have a six cylinders, it would still have the torque necessary to haul large loads.
This technology effectively shuts cylinders off by keeping the exhausting valve closed. This is done through a solenoid control valve assembly. This assembly receives a signal from pressurized oil on when to activate and deactivate the hydraulic lifters. Since the lifters control the output of exhaust and in-take of reactants like fuel and oxygen, the result is that cylinder will be filled with the byproducts of the combustion reaction and no more intake of reactants will take place. These gaseous byproducts in the cylinder act as a gas spring that keeps the piston from contacting the head. Obviously a great number of sensors and electronic controls would be necessary in order to maintain a seemingly seamless transition from cylinder being active to being inactive and vice versa. This would necessitate the altering of several components on the motor. First and most obviously, hydraulic lifters would need to replace to ones that support cylinder deactivation. Secondly, a solenoid control valve assembly would need to be installed in the motor. Thirdly, the current throttle body would need to be replaced by an electronic throttle-controlling device unlike the current mechanical system. This would greatly assist in ensuring that the shutting on and off of the cylinders is very difficult for the operator to notice. In addition new software would be needed to included in the vehicles computer to sense vehicle speed and RPM so that cylinder deactivation would be enabled and disabled at the proper times. This software would also effect the ignition and distributor of the engine so that when the cylinders are not being used spark is not being created by the spark plugs. This may also require that a different distributor be installed on the engine. Also, the fuel injectors would have to be shut down that supply fuel to the affected cylinders so that excess fuel is not used and flooding of the engine does not occur.
When it comes to the systems that cylinder deactivation affects they are throughout the engine and vehicle. The fuel system will require have to supply less fuel so the fuel pump and injectors will be influenced, this in turn brings the heads into the equation. Also, the pistons will no longer be moving and part of the crankshaft will in turn be affected. In reality all moving parts of the engine will feel the affects of the cylinders being deactivated. In the electrical system the computer will be required to be changed and all of the ignition and the sensors will be receiving different signals. The throttle body and intake of air will be changed and during deactivation will be dramatically affected.
Despite the advanced electronic and design, there are few draw backs to this system. First off, it is expensive. All the electronics needed for this make for a more expensive vehicle. Still, the 2011 Chevrolet Tahoe with Active Fuel Management starts at $37,750, while the hybrid starts at $50,735. So despite the initial increased cost to install this system, it is still quite a bit cheaper than a hybrid and the savings in fuel would eventually be worthwhile. Also, another potential drawback is the durability of the technology. Although General Motors first used the technology in 1981, the current system using the well-developed electronic controls debuted in 2005. This means that vehicles using this technology have only been on the road for five years and therefore it is possible that unforeseen failures occur in the system due to the wear and tear of everyday use.
Another design revision that could be made to the GM V6 is the addition of a supercharger to the engine in order to alter the engines intake system. A supercharger in its basic form is an air compressor that is run off of a pulley attached to the crankshaft. It uses the rotational inertia of the crank to rotate two helical shaped shafts that mesh together and compress air. The compressed air is then forced down into the cylinders. Superchargers force more air into each cylinder than they can normally intake by means of atmospheric pressure alone. This is called “boost” and typically a supercharger will create about 10-12 psi of boost. This results in more oxygen to catalyst the combustion of gasoline creating a larger and more evenly distributed explosion across the top of the piston thus creating more horsepower. Because superchargers increase the power of the engine by utilizing more oxygen, it replaces the need for a larger engine. Superchargers condense incoming air so the requisite mass fits in the relatively small volume of the engine, therefore fuel efficiency is increases and cars can be made lighter by reducing the need for extra cylinders to create power and thus reducing the amount of material required to build the engine.
To add the supercharger to the engine slight modifications need to be made to the existing components. The intake manifold needs to be replaced with one that will allow the supercharger to sit atop the engine securely and must contain the fuel injectors. In addition to the manifold the pulley system must be altered. An additional pulley must be added to the crankshaft and a belt must be affixed to the crank pulley and supercharger pulley. Other than these simple modifications nothing else is needed when adding a supercharger.
This design revision takes into account societal, environmental, and economical concerns. The addition of the supercharger would allow this motor to be used in a much greater variety of vehicles. Originally, this motor was designed for use specifically in small trucks and SUVs. The exact model, the LG3 was only used in Blazer's and S10s. The extra horsepower generated by the addition of a supercharger would lead to greater fuel efficiency in smaller cars. The increased fuel economy addresses both economical and environmental concerns. By getting a better mile-per-gallon rating the consumer spends less on gas and gets farther on a tank, which decreases that cars carbon foot print. The extra power addresses societal factors. The supercharger allows the engine to be used in larger trucks that could be used for towing or hauling. For certain consumers this is a desired function.
Convert the Engine to Run on E85
The price of gasoline and the gas mileage of a vehicle almost always are a consideration when a customer decides to purchase a motor vehicle. By converting the LG3 to run on E85 rather than conventional gasoline, the consumer can be sparred some of the pain and frustration of filling up the tank with conventional gasoline. The modifications required to change this engine from running on standard gasoline to E85 would be quite extensive and require an entire reworking of the fuel system as well as other alterations to other components and subsystems.
One of the major differences between gasoline and ethanol is the corrosive nature of ethanol. It is corrosive to the point that all rubber lines must be changed to plastic coated lines.  Also, the alloy that the piston is made out of may need to be altered. The ethanol is corrosive to aluminum which means that if the alloy that the piston is made out of is not strong enough, serious damage could occur. The material the intake manifold is made out of may also need to be altered, since it too is composed of aluminum.  Also, all gaskets in the motor will need to be changed. The corrosive nature of the ethanol requires specialized gaskets be used in order to prevent corrosion. The fuel injector will need to be changed as well. Ethanol has a different stoichiometric ratio, which means a different mix between oxygen and fuel is necessary.  More ethanol will need to be injected into the motor than gasoline. This will be most effectively utilized if a computer is installed in order to properly control the amount of ethanol injected.
The big advantage of E85 is that it addresses the global factor of the country’s dependency on foreign oil. The use of ethanol can greatly decrease the national dependency on foreign oil. This is a major driving factor in the development of E85. It also addresses economic factors. Currently, the national average price of E85 is about $2.51.  The average price of gasoline is about $2.90.  Although it is cheaper by the gallon, ethanol is less efficient than gasoline and ethanol is about 20 to 25 percent less efficient.  This means that it is more expensive to run E85 in a vehicle than it is to run gasoline. Still, E85 address the economic concern of price stability. One of the major issues with fuel prices is the instability. E85 has been much more consistent in terms of price than gasoline over the past two years. When gasoline prices reached their peak in price in June of 2008 at over $4 per gallon, E85 had only reached $3.25 per gallon. This means that at that time, E85 was cheaper than gasoline. In terms of the cost of manufacturing E85 motors, the cost will not rise much at all. The changes to the motor outlined earlier will not drastically affect the cost of production of the engine. Since the idea behind this motor is to be fairly cheap while also providing the consumer with decent fuel economy and power, a switch to ethanol can help stabilize the price of fuel for the consumer. This could greatly sway a perspective buyer who is concerned about rising gas prices.
 "E85 versus Gasoline Comparison Test". Edmunds.com. 12/10/10. http://www.edmunds.com/fuel-economy/e85-vs-gasoline-comparison-test.html?articleid=120863&
"Difference Between Flex Fuel Engines and Gasoline". eHow.com. 12/10/10. http://www.ehow.com/list_5780695_differences-fuel-engines-gas-engines.html
 "E85 Prices". E85price.com. 12/10/10. http://e85prices.com/
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