Group 10 - GM V-6 Engine Gate3

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Contents

Gate 3: Coordination Review

Component Summary

Cause for Corrective Action

Unresolved challenges: A challenge that we have encountered and partially resolved is that there are still a few parts of the engine that we have not been able to identify. Our best resources available to us to determine the parts are the previous groups who disassembled the engine as they may have had a greater knowledge of the parts of the same engine. Because this is an older engine, finding support from GM is almost guaranteed to be a failure. Another option is to get a manual from Haynes of the vehicle that this engine came off of, (most likely a 1985 GMC truck or SUV).

Because we are working with another group on the GM V-6 engine, we have encountered the issue of one group getting to the engine first to dissect it, and then not put it back into the original assembled state. Twice, our group, Group 10, have had to work on either a fully or partially disassembled engine. For the Product Dissection, we tried to change that to a “Product Assembly” and document putting the engine back together. This was not a structured environment to document and understand the parts of an engine. We were pressed for time and had no prior knowledge of how this specific engine was put together. To correct this issue we decided to take the engine apart another separate time. We encountered the same issue where the paired group had taken the engine apart partially and had not put it back together. Because of the efficiency of our Group, we were able to work together to put the engine back together and then take apart and document the entire engine a second time. Our product dissection for Gate 2 contained information and images referenced from the group paired with us and from the group who disassembled the engine last year. This secondary, in-depth dissection provided us with a more accurate and complete dissection of the engine accomplished by our own group. More concisely, our group took the engine apart one single time and assemble the engine three separate times. The last time we assembled the engine, we were able to complete the process in twenty minutes and video record the process.

A video of the assembly of the GM V-6 Engine by Group 10 can be viewed here.

Component Pictures

Table 3.1 Component Pictures
Part Quantity Picture
Fuel Injector Cover 1
Figure 1: Fuel Injector cover
Water Pump 1
Figure 2: Water Pump
Valve Covers 2
Figure 3: Valve Covers
Distributer Shaft 1
Figure 4: Distributor Shaft
Intake Manifold 1
Figure 5: Intake Manifold
Cylinder Heads 2
Figure 6: Cylinder Heads
Lifters 12
Figure 7: Lifters
Lifter Covers 2
Figure 8: Lifter Covers
Push Rods 12
Figure 9: Push Rods
Timing Chain, Cover, Camshaft Sprocket, Camshaft Gear 1
Figure 10: Timing Cover View
Balancing Shaft 1
Figure 11: Balancing shaft
Camshaft 1
Figure 12: Camshaft
Oil Pan 1
Figure 13: Oil Pan
Oil Pump 1
Figure 14: Oil Pump
Crankshaft 1
Figure 15: Crankshaft
Piston 6
Figure 16: Piston and bearings
Flywheel 1
Figure 17: Fly wheel
  • Source: 2008 Group 20

  • Component Function

    Table 3.2 Components Functions and Flows
    Part Performed Function Flows
    Fuel Injector Cover Protects Fuel Injector from dirt and debris that can get under the hood. Used to contain the flows of air from the intake and provide protection and looks.
    Water Pump Driven by the fan belt, the water pump circulates coolant from the bottom of the radiator pan to the engine’s water jacket. These are open areas in the engine that allow water to pass through and cool the engine’s components. Accepts heat from the combustion inside the engine and sends it out to the radiator to release it. Water is heated from the engine, send to the radiator where the heat is dissipated and cooled water is sent back. The pump that moves the water is powered by the rotation of the crankshaft transferred through the serpentine belt.
    Valve Covers Protect the valve train components from elements such as dirt and other debris that could harm the valve system’s performance. It also serves as a pool were lubricating oil collects before dripping back inside the engine through the cylinder heads. Contains oil in the valve train area for lubrication.
    Distributor (Shaft) Transmits high voltage from the ignition coil to the spark plugs in the specific order as determined by the camshaft rotating the distributor shaft's gear. This ensures firing of the correct piston. Mechanical energy is trasmitted from the crankshaft which is translated into a signal from sensing gaps in the spinning shaft. This order determined by the spinning is used to send out electricity from a high voltage source (ignition coil) to the spark plugs. This specific order allows for the spark plugs to fire, igniting the fuel/air mixture, producing thermal heat.
    Intake Manifold Supplies the correct mixture of air and fuel to each cylinder heads. The correct combustion mixture is necessary to optimize the performance of the engine. Air is moved into the manifold and transferred to the cylinders for combustion.
    Exhaust Manifold Collect engine exhaust from each of the cylinders and deliver it to the muffler and exhaust pipe. Waste gases and water vapor from the combustion process are exited through the exhaust. Backpressure is important for increasing the efficiency of the engine so the exhaust cannot simply be evacuated as quickly as possible.
    Cylinder Heads Consists of a platform that rests on top for the cylinders. Contains the valves, spark plugs (not included). The valves regulate air flow into the engine via the intake manifold and regulate exhaust out through the exhaust manifold. Mechanical energy is transferred to specific valve systems. Lifters move on rollers around the cams, pushing up or letting down pushrods which move the rockers, providing pressure on the springs, opening of allowing the closure of the valves. Mechanical energy is used to input air, a component of combustion, and allow the escape of the exhaust, regulating the combustion quality of the engine.
    Lifters, Lifter Covers, Pushrods The rollers contact the camshaft and as the camshaft spins, the offset cams push the lifters (attached to the rollers) up and set them back down. The lifters house the pushrods which transmit the up and down motion of the camshaft into the rockers. The rockers pivot on top of the valve springs which provide a resisting force for the valves. The valves are opened or closed based on the position of the camshaft. Transfer specific rotational position of the camshaft cams to control the position of the valves, which allow in air used in engine combustion. Air from intake provides oxygen that increases the energy of combusting the gas. The exhausted gases are exited when the cams move the appropriate lifters and rods, opening up the appropriate exhaust valve, exiting the heat and spent chemicals.
    Timing Chain,cover The Timing chain controls the timing of the engine’s valves. Connects the crankshaft to the camshaft which in turn will control the opening and closing of the valves.
    Camshaft Sprocket, Camshaft Gear Attaches to timing chain and keeps the timing of camshaft in sync with the rotation of the crankshaft and rotates the balance shaft. Rotational energy from the crankshaft is transferred through a timing chain to the camshaft sprocket which provides rotational energy to spin the shaft.
    Balancing Shaft The firing of the pistons produce mechanical vibrations of the entire engine. The balancing shaft offsets the vibrations so the engine does not shake. A helical gear at the front end of the camshaft attaches directly a gear on the end of the balancing transmitting rotational energy to spin the balancer. Offset weights provide inertia and a force used to counteract the rocking of an engine produced by the movement of the pistons.
    Camshaft Forces the valves open by pushing the rollers which will in turn open the values in an alternating order due to the alternating cams. It also has a helical gear to drive the balancing shaft. Rotational energy from the crankshaft is transmitted through the timing chain. The rotational energy is converted to translational energy to move lifters up and down. Rotational energy is also transferred to the balancing shaft.
    Oil Pan, pump, cooler/distributer Oil pan serves as a reservoir for the oil used to lubricate the engine and its components and for any undesirable deposits that end up in the engine, such as dirt or metal shavings from engine wear. Oil pump obtains oil in the pan through a metal filter and is driven by a gear pump and the engine rotations and distributes it throughout the internal paths of the engine. The oil cooler sends out the oil heated by the running engine to a cooling unit and then returned the cooled oil back into the engine Used for maintenance in lubricating the engine and components. Heat is transferred to the oil, but the oil system is not used explicitly for cooling the engine.
    Crankshaft Connected to pistons by bearing surfaces on offset axis than the crank ends. Allows pistons to rotate shaft. Connected to flywheel at other end for vibration dampening. Accept translational energy from pistons and convert it to rotational energy use to drive wheels and other components.
    Piston Connected to the crankshaft. The head compresses an air and gas mixture which is ignited. The thermal expansion pushes the piston head, connected to the connecting rod to the crankshaft and rotates it. This provides power to the drivetrain and other connected components. Gasoline and air enter the head and are compressed by the piston. Their ignition forces the piston back, converting the chemical energy to translational energy to rotational energy, providing the end-source of power for a vehicle.


    Engine Block The platform in which all engine components are connected to. The block contains the cylinders where combustion occurs. Inputs air and fuel and provides the container where they are combusted. The chemical energy, facilitated by an electrical spark from the spark plugs, is directed to move the pistons in a translational motion. The waste chemicals are rejected by the engine block via the exhaust manifold.


    Flywheel Connected at the end of the crankshaft. Has a high moment of inertia which makes it resistant to sudden changes in velocity. This is a very critical part of the engine since it stores energy from the crankshaft making the it more efficient and also dampens the sudden changes in torque by releasing and storing torque. The inertia caused by the spinning of the flywheel from the rotational energy of the crankshaft provides vibration damping. The inertia stores the energy from the crankshaft and releases it.


    Manufacturing Methods

    Table 3.3 Manufacturing Methods
    Part Method Used Global, Societal, Economic, Environmental
    Fuel Injector Cover Injection Molding because it is plastic with a fairly complex shaft. It would fit into a die. Cheap, easy method for high production of geometrically complex plastics like this one.
    Water Pump Die cast steel part due to not having any requirements for high tolerances. Most likely two casted pieces due to complex shape. Must be resistant to rust because it comes into contact with water. Has to be an easily removed part because it is located in front of the engine block.
    Valve Covers Injection Molding due to simple shape and plastic material. Cheap, easy method for high production of geometrically complex plastics like this one. Must be able to pool oil and drain back through the cylinder heads. This shaping is easily done by injection molding.
    Distributor Inner shaft is turned and the end is machined into a gear. The Cap is injection molded plastic. The distributer must be conductive to transmit voltage. The shaft has a plastic casing for safety reasons.
    Intake Manifold Die Cast Steel with possible side actions as evident of outer surface finish and draft angles. Most likely cast for high volume production at low cost. May be machined for final openings.
    Exhaust Manifold Cast iron as evident of riser marks and casting stamp. The process is cheap for mass production but produces a part the has a long life and can handle harsh exhaust gases. It is important to direct the exhaust away from people and release them into the atmosphere in accordance to societal and environmental regulations
    Cylinder Heads Cast iron due to riser marks and casting stamp. Readily available material that can last and not need to be replaced, lowering cost
    Lifters Independently manufactured, Machined out of steel and turned on lathe, necessary for high tolerances Hydraulic lifters vs. Solid Lifters, whose benefit is longer life and durability and better performance for customer.
    Lifter Covers Injection molded plastic because of complex plastic structure. Allows easier lifter installation for service, reducing time spend on orienting lifters for cheaper and quicker maintenance and repair.
    Pushrods Extruded steel and machined by turning on lathe to create rounded ends. Steel is a strong abundant resource so it is easy to manufacture large volumes.
    Timing Chain,cover Stamped links mechanically press-fit together Chain provides long life, longer than a timing belt alternative. More expensive initially but never has to be replaced unlike timing belt.
    Camshaft Sprocket, Camshaft Gear Cast iron because of rough surface finish with teeth and slots machined out due to cut marks. Cut slots reduce inertia and stresses on components increasing their life.
    Balancer Shaft Cast iron from seam. Purpose is to reduce engine vibration and increase engine smoothness. This is for the benefit of the driver and the engine, increasing life and consumer comfortability.
    Camshaft Made with a special turning process involving spinning axis of camshaft and changing height of cutting bit during rotation. Made of high quality steel with high tolerances as to increase life of component and eliminating service on it, lowering service costs.
    Oil Pan, Pump Die Cast Aluminum pan as shown by casting marks and material lightness. Oil pump is cast iron and formed tubing with a stamped mesh filter. Because of large size of the oil pan, if it was made with any other heavier material, it would multiply the weight of the engine. Aluminum allows it to be light and easily removed. This makes working on engine and oil pan easier to work on.
    Crankshaft Balancers are cast and bearings are first turned and then pressed into balancers with oil holes drilled out. Made with a cheaper method for economic reasons. If machined out of a single piece of steel, would be more expensive, but it would have a longer life.
    Piston Forged Steel Forging creates a much stronger component which is necessary for piston to handle combustion. Costly for mass production but will have to be replaced fewer times.
    Engine Block Die Cast Iron due to size, outside surface finish, riser and seam marks, and riser stamp. Main part of engine easily mass produced using casting process and strong enough to not need replacing. Though the process of pouring liquid metal into the cast releases harmful gases into the atmosphere, damaging the environment.
    Flywheel Machined out of steel plate. Teeth and slots cut using machining processes Flywheel reduces driveshaft and crankshaft vibrations by providing damping inertial forces. Reducing wear rate and life of engine and comfort of driver.


    Component Complexity

    Table 3.4: Scale
    Value Complexity Interaction Complexity
    1 Simply structured component, basic geometric shapes with no complex features, easily reproduced in high volume using a small number of basic machines. Interacts with less than two components and has a simple function in that interaction
    2 Structure is not simple, has limited number of complex features, reproduced with little difficulty in medium. dependent simple motion, or independent non-simple motion
    3 Neither a simple or purely complex part, has a mix of both levels of complexity. Manufactured using several simple machines, or using a limited ability of complex machines. Reproduced with some difficulty. Has connections to several different parts but is not a center for the system.
    4 Contains few simple features and several complex features. Requires special equipment to manufacture and is reproduced with moderate difficulty in a low volume. Interaction with multiple parts, complex motion and connects several systems
    5 Contains many complex feature that are time consuming and difficult to reproduce, needing high-tech machines to accurately create component. interaction with many components and systems, an integral part that performs several complex functions.



    Table 3.5
    Part Complexity Scale Complexity Interaction Complexity Scale Complexity of Interaction


    Fuel Injector Cover 2 Manufactured using a complex injection mold to fit over the fuel injector. Must be cut to allow throttle body through. Still easy to make after mold is made. 1 Only servers a protector for the fuel injector and throttle body. Has no moving parts.
    Water Pump 3 Manufactured using a complex cast iron mold but is still easy to reproduce high volumes of the water pump after the mold is made. 3 Connected with the fan belt and is responsible for distributing water through the engine’s jacket.
    Valve Covers 2 Manufactured using a complex injection mold to fit over the valves. 1 Serves as a protector for the valves but is needed to pool oil and later drip oil back through the cylinders.
    Distributor 3 Requires 3 different manufacturing processes. Injection molding for the plastic cap and casing, die casting for the inner shaft and turning for the gearing at the end of the shaft. 4 Connects the ignition system to the spark plugs and is responsible for the correct firing order of the pistons.
    Intake Manifold 2 Manufactured using a complex die casting mold. The shape is very complex since it needs to house the distributor and the throttle body. Relatively easy to reproduce after mold is made. 3 Must interact with each cylinder head and supply the correct mixture of combustion gas which can be very complex.
    Exhaust Manifold 1 Easily made by a simple die casting mold 2 Only interacts with the cylinder head to collect engine exhaust and deliver it to the exhaust pipe.
    Cylinder Heads 4 Manufactured using numerous processes. The housing itself is die casted, and the valves extruded and further machined to obtain the desired shape. 4 Valves interact with cylinders to regulate airflow into the cylinders via the intake manifold and regulates exhaust out through the exhaust manifold. The valves are opened and closed using the force of the push rods.
    Lifters and Lifter Covers 4 The lifters are made of 3 main parts that are manufactured separately using different processes. The casing, spring and wheel all need to have high tolerance since it contains hydraulic fluid. The lifter covers are easily made using injection molding. 3 The lifters are moved by the camshaft and force the valves open by pushing the push rods.
    Pushrods 1 Push rods are easily extruded and machined on the tip to make the ball on top. 1 Simply transfer the force from the lifters to the valves.
    Timing Chain, 3 Involves two different steps and processes. Stamping each link and assembling each link together. 3 Connected to 3 different significant parts : camshaft and crankshaft, and is responsible for the timing of the valves.
    Camshaft Sprocket, Camshaft Gear 2 Both are machined easily and quickly. 3 Attaches the camshaft to the timing chain and is critical to the proper rotation of the camshaft.
    Balancing Shaft 1 Simple cast iron design. 2 Connected to the camshaft via a helical gear which transmits rotational energy to the balancer shaft.
    Camshaft 4 Most likely lathed. Each lobe must be offset of each other making it necessary to move the lathe up and down at different points and times. 4 Connected to the crankshaft via the timing chain. Moves lifters up and down to open valves.
    Oil Pan 2 Oil pan is Die casted aluminum. Simple design and easy to produce high volumes. 1 Oil Pan is simply a reservoir for oil.
    Oil Pump 3 Several processes including die casting and stamping to assemble the oil pump. 2 Connected to a gear pump, distributes oil throughout the engine.
    Crankshaft 5 Several manufacturing processes where used including casting and lathed connecting rod bearings. Each bearing must be perfectly in line. 5 Translated linear energy from the pistons into rotational energy which powers everything on the engine. Almost every part is dependent on the crankshaft.
    Piston 2 The piston is forged relatively easily using a die cast molding 2 Contained in each cylinder and attached to crankshaft. Pushes on crankshaft when the cylinder it is fired.
    Engine Block 2 Entirely casted out of iron using a extremely intricate mold. Contacting surfaces are cleaned using machining processes. 4 All components are directly or indirectly attached to the engine block.
    Flywheel 2 Each tooth of the wheel is machined out. A relatively easy and cheap process. 2 Connected to crankshaft to dampen the uneven rotations of the crankshaft.

    Component Form

    Table 3.6 Component Form
    Part General Shape Shape in Respect to Task Weight (Rough) Material Aesthetic Properties
    Flywheel Cylindrical shape (thin) with teeth along the outer edge to hold the timing chain A cylindrical shape is necessary for symmetrical rotational motion. The flywheel must rotate symmetrically in order to move the timing chain properly. 10 pounds The flywheel is made of cast iron. This is a necessary material because it is very strong and the flywheel undergoes a lot of stress as it spins at a high velocity. Cast iron is appropriate for most parts of the engine because of its strength, low cost, and high availability. Smooth surface finish; this is necessary to reduce friction as it spins.
    Fuel Injector Cover A more complex shape, it is roughly rectangular with curved edges. The majority of it extrudes outward from the base (where it is connected to the engine block) to fit over the shape of the fuel injector. It must house the fuel injector so it is shaped accordingly in order to fit over it. The general shape must fit on the engine block and line up with the holes where it is bolted down. 1 pound It is made of plastic. A metal material is not necessary since its purpose is just to cover the fuel injector. It undergoes no motion or friction from moving parts, therefore plastic will sustain itself while the engine is running. The plastic used is black. It serves an aesthetic purpose because it sits right on the top of the engine, and black plastic is visually pleasing while on top of cast iron. It has a smooth finish to further increase visual satisfaction.
    Water Pump The moving component of the water pump is cylindrical. Its housing is a more complex shape to allow attachment to the engine. To enable its rotation it is connected to a belt. In order for smooth rotation to occur it must be axially symmetric (circular). 10 pounds It is made out of cast iron in order to withstand high torque and pressure from the belt. Cast iron is very durable, making it suitable for its function. The water pump is located inside the engine; therefore aesthetics are not a concern. It is not particularly smooth because it must provide enough friction to grip the belt without slipping.
    Valve Covers It is roughly a rectangular box with rounded edges, and it is big enough to cover the valves, lifters, and pushrods. The shape is necessary to cover the valves, lifters, and pushrods and to keep the engine compact and symmetrical. 1 pound It is made of plastic. Its purpose is to cover the valves, so plastic qualifies for this purpose, while adding minimally to the weight of the engine. The black plastic used serves an aesthetic purpose, as it is exposed to the outside and is viewed by people. It has a smooth finish to increase visual satisfaction.
    Distributor It is circular shaped at the top and is connected to a shaft where it connects to the camshaft through a gear. It must be circular in order to connect to the timing gear at the bottom of the shaft. 1 pounds The shaft is made of iron and housed in plastic. The shaft must be made of a strong material because it is constantly undergoing stress from the timing gear. The housing must not conduct electricity due to safety issues and disruption of other systems and is therefore made of plastic. The top of the distributor is exposed to the outside of the engine, so it is covered with an off-white cap, along with the black plastic housing. It serves an aesthetic purpose.
    Intake Manifold Rectangular with angled edges in order to sit on top of the engine block. It contains spaces and holes. It must sit on top of the engine block and fit between the valve trains, which is a rectangular shape. It must contain holes and spaces to allow passing of air and fuel to the cylinder heads. 20 pounds Steel is necessary due to the high pressure and fuel it is exposed to. The intake manifold serves no aesthetic purpose and is dull silver colored. It does not have a smooth finish because it does not come in direct contact with moving parts.
    Exhaust Manifold Consists of cylindrical curved tubes. The tubes must fit to the sides of the engine. The tubes are cylindrical to fit to the cylindrical muffler and exhaust pipe. 20 pounds (each) It is made of cast iron. It must be a strong material in order to withstand the high temperature exhaust it carries. The cast iron has a rough surface and is a rusty brown color. It is not easily visible when sitting in a vehicle and so serves no aesthetic purpose.
    Cylinder Heads The outer surface is rectangular with rounded edges. It is a few inches deep to allow the lifters, springs, and pushrods to stick out of it. Each one must rung along the side of the engine and hold the pushrods, lifters, and springs in place. It contains holes for the pushrods to go through and extrusions for the lifters to sit in the proper location. 30 pounds (each) The cylinder heads are in direct contact with many moving parts, such as the pushrods and lifters, and undergoes a large amount of stress, friction, and heat. It is made of cast iron in order to withstand these stresses and temperatures. It serves no aesthetic purpose and has a rough surface. The holes through which the pushrods run have a smooth finish in order to reduce friction.
    Lifters, Lifter Covers, Pushrods The lifters are cylindrical shaped and hold a cylindrical wheel that is free to rotate on the camshaft. The lifter covers are somewhat v-shaped with curves at the top to act on the pushrods and springs. The pushrods are long, thin cylinders. The lifters must be cylindrical in order to fit in the holes leading to the camshaft. The shape of the lifter covers is designed specifically to fit on the top of the pushrods and the springs. The pushrods are cylindrical to allow free motion in the holes they are held in. Each lifter weighs about 8 ounces, each lifter cover weighs approximately 4 ounces, and each pushrod weighs approximately 2 ounces. The lifters are made of stainless steel, which allows for a very smooth finish and thus low friction movement. Low friction allows for maximum energy conversion from the camshaft. Lifter covers are made out of cast iron which can withstand the tremendous force applied to them by the pushrods and springs. Pushrods are made from steel, allowing low friction motion. Lifters have a very smooth finish to allow free motion with low friction. Lifter covers have a rough finish because their rocking motion is not hindered by friction. Pushrods have a very smooth finish to minimize friction in their motion.
    Timing Chain,cover, oil spasher The timing chain consists of many small links. The links of the chain consist of very small cylinders held together to connect the crankshaft to the camshaft through gears. The timing chain weighs approximately 5 pounds. The links are made of machined steel, a strong and smooth material allowing for low friction rotation around each other’s connection points. The links of the chain have a smooth finish to allow low friction rotation.
    Camshaft Sprocket, Camshaft Gear The gear is a very thin cylinder with teeth along the outer edge for connection to the timing chain. The gear is cylindrical to allow smooth rotation about its axis. The teeth are necessary for connection to the timing chain. 1 pound Made of steel to withstand the force it experiences from the timing chain and to allow a smooth finish to reduce friction. A smooth surface finish to allow low friction rotation.
    Balancer Shaft A long cylindrical shaft with two larger half cylinders for balancing. The long cylinder must extend through the length of the engine. The two half cylinders attached serve as weights, allowing the balancer to dampen the vibrations from the pistons. 20 pounds Cast iron, a heave material allowing for maximum vibration absorption. A rough finish for the most part, it is basically a weight so a smooth surface is unnecessary. It has a smooth finish where it comes in contact with the engine to allow smooth rotation.
    Camshaft A long cylindrical shaft with a helical gear and twelve (flat) egg shaped cams. It is necessary that it is primarily a long cylinder because it must rotate along its axis. The cams extrude out from the shaft to apply a force on the rollers during rotation. The helical gear drives the balancer shaft. 10 pounds Machined steel, this is necessary because the smooth finish allows for low friction rotation. As it rotates the cams push the rollers with low friction, allowing for a more efficient energy transfer process. The smooth finish is for functional purpose rather than aesthetics. The smoothness of the shaft allows for low friction motion and conservation of energy in the engine.
    Oil Pan, pump, cooler/distributer The oil pan consists of a flat end with rounded sides which allows for connection to the engine. The other end is a reservoir to hold oil. The flat end of the oil pump allows for connection to the engine. The deep reservoir allows for oil containment. 20 pounds Aluminum; the oil pan is a large component so a light weight metal is optimal to minimize engine weight. Also aluminum is resistant to rust, ensuring that the oil pan will not wear away and be unable to hold oil. The pan contains many ridges from the mold used to shape it. It serves no aesthetic purpose as it is located on the bottom of the engine and is not easily visible.
    Crankshaft Consists of cylinders offset from the axis of rotation, along with 5 offset plates. As it rotates, the offset cylinders apply forces on each shaft. The cylinders must be offset in order to provide a varying distance from the rotational axis to push the shafts. 45 pounds Steel; the shaft must withstand tremendous forces as it pushes the piston shafts. Steel is a strong and inexpensive material, qualifying it for the task. The offset cylinders have a smooth finish because they must rotate very rapidly. A smooth finish allows for low friction rotation within the brackets that connect it to each piston shaft.
    Piston Cylindrical for approximately one and one half inches at the top, cylindrical with two flat sides at the bottom. It is also hollowed out. The cylindrical part on the top fits tightly with the cylinder it is housed in to ensure no loss of pressure. The flat sides underneath the cylinder provide a connection for the shafts. It is hollowed out to allow the shaft’s connection. 3 pounds Machined aluminum; aluminum must be completely smooth, so the casting process cannot be used. The sides have a perfectly smooth finish because there must be very low friction in the cylinders as the pistons move. The top surface is not as smooth because it is not in direct contact with other engine components, only fuel and air.
    Engine Block A relatively complex shape, basically a long (3 dimensional) hexagon with many empty compartments to house many components of the engine. Two sides of the “hexagon” provide a location for the valve trains to sit, along with holes for the push rods and the cylinders. The two sides adjacent to these provide a location for the exhaust manifolds. The side between the valve trains is the location of the intake manifold. 160 pounds Cast iron; a very durable material is needed because it must withstand tremendous pressures and temperatures. Cast iron is a cheap and durable material. It serves a variety of functions, so aesthetics are not the main focus. All of the holes/cylinders have smooth finishes to allow low friction motion while the outside surface is not as smooth.

    Design Revisions

    • One design revision we recommend is using a stamped oil pan, instead of a die cast aluminum pan. Stamped steel is stronger and more durable and resists impacts better than cast aluminum. Cast parts can crack when struck and this could cause a catastrophic failure of the engine, from loss of oil. The oil pan is located on the bottom of the engine and has a high risk of being hit by debris. Strengthening this part will make the engine more durable. While steel can rust, it can be coated with rust inhibitors to help prevent this. A steel pan would be more expensive but it would make a more durable engine.

    Steel Oil Pan

    • A second revision is to use a cast aluminum engine block. Aluminum is much lighter than cast iron with a density of about 2.7 g/cm^3 compared to cast iron at a density of about 7.85 g/cm^3. This change can greatly decrease the overall weight, allowing for a greater power to weight ratio. The downside of cast aluminum is that it is more expensive than cast iron. For example, if you were to buy an aftermarket aluminum engine block would cost about $4000 for a V8 while a cast iron block would be about $600 according to JEGS High Performance.

    Aluminum Engine Block

    • A third design revision would be too make the water pump mounts asymmetrical. This revision doesn't affect performance or efficiency but it does make maintenance easier. Through our experience we noticed that the water pump could be installed upside down without any major differences. Besides plumbing there are no geometrical differences between the pump in it's correct position and inverted. This could easily be fixed by making the mounts angled, this way the holes wouldn't line up when inverted.

    Solid Modeled Assembly

    Figure 1.1 shows an assembled view of the crankshaft, piston, connecting rods, flywheel, and camshaft. Figure 1.2 shows the camshaft, Figure 1.3 shows the crankshaft, and Figure 1.4 shows the assembled piston and connecting rod. Theses are some of the main parts of the engine. They are involved in the conversion of linear motion to rotational motion. SolidWorks 2010 was used to create and render these models. SolidWorks is a very powerful platform and is used throughout the Mechanical Engineering industry. One of the group members had prior experience with SolidWorks and was able to create the model.

    Figure 1.2
    Figure 1.3
    Figure 1.4
    Figure 1.1




    Intro To Engineering Analysis

    The analysis process will be used to determine the thermal efficiency of the engine. The purpose of this is to help determine the maximum power output of the engine and how to maximize it, and whether or not this is a viable engine design. By analyzing the compression ratio, fuel-air mixture, and material properties of the engine, you can determine the maximum power output of the engine. Using a lean fuel-air mixture (very little fuel) can result in a higher fuel efficiency, and a lower K-value, and therefore a higher thermal efficiency. The aluminum block will reduce the weight of the engine and also increase the strength in high horsepower applications but also have higher probability of distortion under stress. The compression ratio can also be increased to increase efficiency and power output of the engine. It can only be increased to the limit at which engine knock occurs.

    Engineering Analysis

    The following engineering analysis procedure will determine the thermal efficiency of the GM V6 based on the Otto Cycle.


    Problem: Calculate the thermal efficiency using the given compression ratio and K-value.


    Diagram:

    Source: Group 18 Fall 2009


    Assumptions:

    • The working fluid is Air and is an Ideal Gas

    • The K-value for air is 1.4

    • The compression ratio is 9.4

    • Operates on a closed loop


    Governing Equations:


    Goveq.png



    Calculations:

    Workeq.png


    Solution Check:

    All of the values in the calculations are ratios therefore they have no units. The K-value is determined by the ratio of the Cv over the Cp. Cv is the specific heat at a constant volume and Cp is the specific heat at constant pressure. Since k=Cv/Cp, the units of the two specific heats will cancel and leave it unit-less. The given R-value has no units so we can conclude that the final answer is also unit-less. This answer is a high estimate because the other factors that have been neglected would all bring down the thermal efficiency. This answer seems to be correct because it is the maximum thermal possible with these neglections made.


    Discussion/Interpretation:

    This calculation gives the maximum thermal efficiency that could be achieved by an engine operating on the Otto Cycle with a compression ratio of 9.4. The actual efficiency would be lower because the K-value will be lower than ideal air. Using a fuel air mixture will give a higher K-value, resulting in a lower efficiency. The efficiency can be increase by increasing the compression ratio and leaning out the air-fuel mixture. Using this analysis, the efficiency can be maximized to make a better engine. Adjusting the the compression ratio can make the engine more fuel efficient.

    References


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