Group 14 - GM 4 Cylinder Engine 2 - Revision history

MAE 277 2010 Group 14: /* Disassembly-Assembly */

2010-12-18T21:48:15Z

Disassembly-Assembly

MAE 277 2010 Group 14: /* Original Assembly */

2010-12-18T21:47:54Z

Original Assembly

MAE 277 2010 Group 14: /* Document the connection of subsystems */

2010-12-18T21:21:37Z

Document the connection of subsystems

MAE 277 2010 Group 14: /* Document the connection of subsystems */

2010-12-18T21:18:10Z

Document the connection of subsystems

MAE 277 2010 Group 14: /* Alternative Profiles */

2010-12-18T21:00:50Z

Alternative Profiles

MAE 277 2010 Group 14: /* Alternative Profiles */

2010-12-18T20:59:41Z

Alternative Profiles

MAE 277 2010 Group 14: /* Alternative Profile */

2010-12-18T20:58:32Z

Alternative Profile

MAE 277 2010 Group 14: /* Alternative Profile */

2010-12-18T20:57:38Z

Alternative Profile

MAE 277 2010 Group 14: /* Product Archaeology: Product Explanation */

2010-12-18T20:49:03Z

Product Archaeology: Product Explanation

MAE 277 2010 Group 14: /* Product Analysis */

2010-12-18T20:45:53Z

Product Analysis

@@ Line 1,888: / Line 1,888: @@
 ===Disassembly-Assembly===
-	In completing the assembling of the engine, a few comparisons between the reassembly and disassembly can be made. For the most assembly parts, many of the individual steps bore great similarity to their disassembly step. For example, a bolt that may have been rotated counterclockwise and out during the removal, would be rotated clockwise and in for the replacing. Many of the steps have this property of ‘mirroring’ the disassembly for that component.
+	Re-assembling the engine, in 90% of the instances, merely required a reversal of the disassembly process.  One of the few components that required special re-assembly procedures was the piston.  The piston rings require preloading for the piston to be properly installed.   This preloading also required a special tool.  Without the tool, there is a potential for damage to the cylinder.  In the disassembly process, the parts were simply tapped and pulled to remove it.  No need for any particular attention was required.  Many of the components can be removed independently, with no related sequence of disassembly.
-	However, there do exists steps that do not reverse in such a simple manner. The pistons, as the main example, created unique a situation for their assembly step that did not bare resemblance to their disassembly step. In removal, the pistons were simply tapped out of their cylinders. For reinsertion though, a piston ring compressor was necessary to hold down the piston rings as a piston was slowly pushed back into its cylinder. In process and difficulty, the assembly and disassembly steps do not mirror each other.
-	Thus overall, the reassembly is very similar to a reversal of the disassembly. Some steps are independent of the entire engine and can be done at any time, while other steps must be assembled in reverse of their disassembly.
 ==System Design Revisions==

@@ Line 1,884: / Line 1,884: @@
 ===Original Assembly===
-	The original assembly process would not have been far different from the reassembly done by groups 12 and 14. Steps of higher difficulty, such as the insertion of the pistons and the harmonic balancer would’ve likely have been done with higher precision and more powerful mechanical devices. However, the engine would’ve still be generally assembly by human laborers much in the manner than the group reassembly was done. It should be noted though that if the engine were being assembled for actually running and usage, greater accuracy would be placed on each step. For example, a bolt being rotated into place would be done with greater force to help insure it does not come loose from the engine.
+	The advantages of OEM (original equipment manufacture) assembly include things like ergonomic assembly aids (lifts), automated fastener attachment, and in process inspection techniques.  These things aside, the parts go together in the same sequence and require approximately the same effort.  Much more care may have been taken to ensure the proper function of the engine for running and installation into its final, in-vehicle, home.  Proper torques, fluid levels, and other factors would be included in the types of attributes that fall into these categories.
-−
 ===Disassembly-Assembly===

@@ Line 536: / Line 536: @@
 We identified the following connections between the systems:
-First, it must be noted that the combustion system is the single function connected to all systems by at least one of the 4 transfer modes available, namely; physical, information, mass, and energy.  Several types of sealing were used, but this will be detailed in the other subsystems. With that said, we can continue on to the remaining systems.
+''Combustion''
 ''Air Intake''
-The air intake was connected to the combustion system physically and transferred both mass and kinetic energy (air at a flow rate).  It also provided signals to the electrical system (for feedback and control) through sensors placed strategically in the air stream.  The reason they are connected is to provide an efficient transfer of the air, while allowing the components to be separated for service or maintenance.  The method used for connection was “threaded fasteners with a compression seal” between the mating surfaces.  Performance, namely a leak free conduit, affects the connection type in that the joint must withstand a severe environment of heat, vibration, automotive fluids, and dirt for extended periods of time.
+:The air intake was connected to the combustion system physically and transferred both mass and kinetic energy (air at a flow rate).  It also provided signals to the electrical system (for feedback and control) through sensors placed strategically in the air stream.  The reason they are connected is to provide an efficient transfer of the air, while allowing the components to be separated for service or maintenance.  The method used for connection was “threaded fasteners with a compression seal” between the mating surfaces.  Performance, namely a leak free conduit, affects the connection type in that the joint must withstand a severe environment of heat, vibration, automotive fluids, and dirt for extended periods of time.
 ''Fuel System''
-The fuel system, as noted above, was also connected to the combustion system and provided mass transfer in the form of fuel to the cylinder through the fuel rail.  The connection was formed by an elastomeric radial seal (not an o-ring) and had physical contact with the combustion system through the injectors, but isolated (cushioned) by the elastomeric seal.  Threaded fasteners were used only to prevent the component from being vibrated or ejected out of position.  The reason for this connection is primarily to prevent fuel leaks while allowing for some flexibility in the connection.  This system is essential to the operation of the engine, so performance is critical.  The sealing system appears to be very robust in that it was simple, but a very positive connection.
+:The fuel system, as noted above, was also connected to the combustion system and provided mass transfer in the form of fuel to the cylinder through the fuel rail.  The connection was formed by an elastomeric radial seal (not an o-ring) and had physical contact with the combustion system through the injectors, but isolated (cushioned) by the elastomeric seal.  Threaded fasteners were used only to prevent the component from being vibrated or ejected out of position.  The reason for this connection is primarily to prevent fuel leaks while allowing for some flexibility in the connection.  This system is essential to the operation of the engine, so performance is critical.  The sealing system appears to be very robust in that it was simple, but a very positive connection.
 ''Cooling System''
-The cooling system is connected to the combustion system indirectly through the crankcase.  It is also connected indirectly to the lubrication system in the same fashion.  It is connected to the electrical system through a sensor.  The system primarily allows for the flow of mass (coolant) which also absorbs energy from the metal surfaces as it passes over them.  When looking at the connection at the water pump, a flange & gasket are used to seal the connection.  When looking at the coolant tube connection, an o-ring seal is used with 2 bolts.  Why is this?  The pump has to withstand a significant load from the pulley and justifies the sturdy flange and gasket connection.  The cooling tube, since there are no forces on it, has the o-ring seal, which is much less robust.  The performance effects are that, without cooling, damage to the primary function could occur.  Sealing and connection is critical.
+:The cooling system is connected to the combustion system indirectly through the crankcase.  It is also connected indirectly to the lubrication system in the same fashion.  It is connected to the electrical system through a sensor.  The system primarily allows for the flow of mass (coolant) which also absorbs energy from the metal surfaces as it passes over them.  When looking at the connection at the water pump, a flange & gasket are used to seal the connection.  When looking at the coolant tube connection, an o-ring seal is used with 2 bolts.  Why is this?  The pump has to withstand a significant load from the pulley and justifies the sturdy flange and gasket connection.  The cooling tube, since there are no forces on it, has the o-ring seal, which is much less robust.  The performance effects are that, without cooling, damage to the primary function could occur.  Sealing and connection is critical.
 ''Exhaust System''
-The next subsystem is the exhaust and was connected to the combustion system with threaded fasteners using a compression seal.  They are connected in this fashion to allow for the transfer of mass & energy, in the form of exhaust, while allowing service & maintenance.  Information is also transferred to the electrical system in the form of voltage from the oxygen sensor to provide feedback for control of the engine. Performance affects the seal of this system in that a leak of exhaust gases would not critically affect the operation, but degrade the efficiency/effectiveness.
+:The next subsystem is the exhaust and was connected to the combustion system with threaded fasteners using a compression seal.  They are connected in this fashion to allow for the transfer of mass & energy, in the form of exhaust, while allowing service & maintenance.  Information is also transferred to the electrical system in the form of voltage from the oxygen sensor to provide feedback for control of the engine. Performance affects the seal of this system in that a leak of exhaust gases would not critically affect the operation, but degrade the efficiency/effectiveness.
 '' Lubrication System''
-The fifth subsystem is the Lubrication system, which directly and indirectly connects to the combustion system.  The indirect connection is by way of heat transfer from the metallic surfaces to the lubricant as it comes in contact with all of the moving (and many non-moving) parts in the crankcase, valve housing, and cylinder head.  Some mass transfer to the oil, in the way of gases and small particles occurs, through very small leaks from the combustion system. Also, the direct flow of small amounts of lubricant to the cylinder also occurs (an unwanted connection), but it does find its way in because of the nature of the piston ring sealing mechanism used to separate the two subsystems.  This seal is a metal to metal seal formed by piston ring being oversized to the cylinder bore causing pressure between the two very smooth surfaces.  This allows for motion of the piston while minimizing the transfer of material between the two systems.
+:The fifth subsystem is the Lubrication system, which directly and indirectly connects to the combustion system.  The indirect connection is by way of heat transfer from the metallic surfaces to the lubricant as it comes in contact with all of the moving (and many non-moving) parts in the crankcase, valve housing, and cylinder head.  Some mass transfer to the oil, in the way of gases and small particles occurs, through very small leaks from the combustion system. Also, the direct flow of small amounts of lubricant to the cylinder also occurs (an unwanted connection), but it does find its way in because of the nature of the piston ring sealing mechanism used to separate the two subsystems.  This seal is a metal to metal seal formed by piston ring being oversized to the cylinder bore causing pressure between the two very smooth surfaces.  This allows for motion of the piston while minimizing the transfer of material between the two systems.
 ''Electrical / Spark''
-Electric & Spark subsystem is connected to combustion system, the intake system, the lubrication system, and the exhaust system.  Each has an energy transfer, of one kind or another, and in many cases, also a signal or information transfer, via sensor.  The energy transferred directly to the spark plug initiates the combustion reaction as the electric energy is dissipated as light and heat in the cylinder. The connection to the cylinder is through the threaded body of the spark plug and sealed by a compression ring.  This provides a seal that will contain the pressures seen in the piston and allows for the proper grounding of one of the poles of the spark plug, while insulating it from the other pole.  The performance affect of this seal is also critical in that a loss of pressure will degrade or negate the operation of the engine, but still must provide for service or maintenance.  This is a critical seal.  For each of the sensors, the sealing is usually to provide protection from whatever fluid is being sensed, whether it be air, oil, exhaust, or coolant.  Oil, water, and air have o-ring seals with threaded fasteners, while the exhaust is welded permanently in place.  O-rings provide seals with minimal leak while allowing for service.  The connection at the exhaust is permanent, clearly to ensure no leak, regardless of service.
+:Electric & Spark subsystem is connected to combustion system, the intake system, the lubrication system, and the exhaust system.  Each has an energy transfer, of one kind or another, and in many cases, also a signal or information transfer, via sensor.  The energy transferred directly to the spark plug initiates the combustion reaction as the electric energy is dissipated as light and heat in the cylinder. The connection to the cylinder is through the threaded body of the spark plug and sealed by a compression ring.  This provides a seal that will contain the pressures seen in the piston and allows for the proper grounding of one of the poles of the spark plug, while insulating it from the other pole.  The performance affect of this seal is also critical in that a loss of pressure will degrade or negate the operation of the engine, but still must provide for service or maintenance.  This is a critical seal.  For each of the sensors, the sealing is usually to provide protection from whatever fluid is being sensed, whether it be air, oil, exhaust, or coolant.  Oil, water, and air have o-ring seals with threaded fasteners, while the exhaust is welded permanently in place.  O-rings provide seals with minimal leak while allowing for service.  The connection at the exhaust is permanent, clearly to ensure no leak, regardless of service.
 ''Motion Translation System''
-The Motion Translation Subsystem is the basis of which all the other subsystems form their location or orientation because it is what provides the energy to operate the other systems. It is connected to the combustion system through the pistons & piston rods, fuels system through the fuel pump, the coolant system through the water pump and cooling circuit, the lubrication system through the oil pump along with the various ports and channels.  Some contact also occurs with the moving components causing splash, and the electrical system is connected through the alternator and receives signals from the rpm sensor. Each is physically connected and involves a transfer of energy of some kind.  The “reason why” they are connected is to facilitate this energy transfer and the manner in which they are connected is by pulley & bearing components with the exception of the lubrication system.  The lubrication system not only has a pump, but also depends on a “splash” type of distribution caused by the moving components that are bathed in lubricant.  The performance influences this subsystem in that it is the source for the other subsystems to be powered.  Connection, sealing, and interaction all play critical roles, for example, lubrication; all moving parts have to be in contact with the lubricant system in some way to reduce friction and transfer heat.
+:The Motion Translation Subsystem is the basis of which all the other subsystems form their location or orientation because it is what provides the energy to operate the other systems. It is connected to the combustion system through the pistons & piston rods, fuels system through the fuel pump, the coolant system through the water pump and cooling circuit, the lubrication system through the oil pump along with the various ports and channels.  Some contact also occurs with the moving components causing splash, and the electrical system is connected through the alternator and receives signals from the rpm sensor. Each is physically connected and involves a transfer of energy of some kind.  The “reason why” they are connected is to facilitate this energy transfer and the manner in which they are connected is by pulley & bearing components with the exception of the lubrication system.  The lubrication system not only has a pump, but also depends on a “splash” type of distribution caused by the moving components that are bathed in lubricant.  The performance influences this subsystem in that it is the source for the other subsystems to be powered.  Connection, sealing, and interaction all play critical roles, for example, lubrication; all moving parts have to be in contact with the lubricant system in some way to reduce friction and transfer heat.
-The interconnection of subsystems are affected by global factors in that the manufacture & recycle-ability of each of the components have standards for each country, that if not managed properly or with sensitivity, will limit the markets to which it can be made available.  Societal factors include the emissions of the engine, so as to not be detrimental to the overall population, and met US requirements.  Along the same lines, environmental factors influence the treatment of waste from the manufacture, the resources used to create the components, and the materials depleted in the process.  Since the majority of the components are metals, a very high percentage are recyclable, which is very positive for the environment.  Economic factors influenced the connections of the components by limiting the cost of these connections and creating a balance between the money spent and the effect of proper connection (or improper connection).  This is pointed out in the subsystem paragraphs, but in general, this is accomplished by minimizing the number of fasteners or through the use of inexpensive materials.
+''Subsystem Arrangement''
-The arrangement of subsystems appears to be driven by the source power that runs the component and the primary application of its function.  For example, the cooling system; has the water pump at the front of the engine where power is distributed to many of the components.  This also provides an excellent area to indirectly interface with the lubrication & combustion components through porting and coolant circuits in the cylinder head and crank case.  In the same fashion, the electrical system begins at the same place, at the front of the engine to receive its power, and then distributed to areas where it is needed.  Proximity of the component depends primarily on these two things; where it gets its power and where the component performs its function.  Some components cannot directly interact because of adverse effects.  This includes the lubrication system and the cooling system.  Since the coolant causes corrosion, it defeats the lubrication subsystem and must be kept separate.  However, it is still important that there be an exchange of heat to control operating temperature.  The same applies to the electrical and cooling system.  Interface between these two systems is primarily through sensing devices because of the coolants ill affect on the electrical system.  We can use the same thinking with the electrical and the fuel system, since the advent of a spark in the presence of fuel would be catastrophic, it is important to keep these two subsystems separate until it is time to ignite the fuel deliberately.  However, a completely different reasoning arises between fuel and coolant, i.e.; the fuel does not need to be cooled, so there is no reason to bring the two together under these circumstances, and in the same fashion, exhaust and fuel also never need to be in contact and it is important to keep these two separate to avoid any additional instability of the fuel prior to combustion.
+:The arrangement of subsystems appears to be driven by the source power that runs the component and the primary application of its function.  For example, the cooling system; has the water pump at the front of the engine where power is distributed to many of the components.  This also provides an excellent area to indirectly interface with the lubrication & combustion components through porting and coolant circuits in the cylinder head and crank case.  In the same fashion, the electrical system begins at the same place, at the front of the engine to receive its power, and then distributed to areas where it is needed.  Proximity of the component depends primarily on these two things; where it gets its power and where the component performs its function.  Some components cannot directly interact because of adverse effects.  This includes the lubrication system and the cooling system.  Since the coolant causes corrosion, it defeats the lubrication subsystem and must be kept separate.  However, it is still important that there be an exchange of heat to control operating temperature.  The same applies to the electrical and cooling system.  Interface between these two systems is primarily through sensing devices because of the coolants ill affect on the electrical system.  We can use the same thinking with the electrical and the fuel system, since the advent of a spark in the presence of fuel would be catastrophic, it is important to keep these two subsystems separate until it is time to ignite the fuel deliberately.  However, a completely different reasoning arises between fuel and coolant, i.e.; the fuel does not need to be cooled, so there is no reason to bring the two together under these circumstances, and in the same fashion, exhaust and fuel also never need to be in contact and it is important to keep these two separate to avoid any additional instability of the fuel prior to combustion.
 ==Part Location Reference ==

@@ Line 537: / Line 537: @@
 First, it must be noted that the combustion system is the single function connected to all systems by at least one of the 4 transfer modes available, namely; physical, information, mass, and energy.  Several types of sealing were used, but this will be detailed in the other subsystems. With that said, we can continue on to the remaining systems.
 The air intake was connected to the combustion system physically and transferred both mass and kinetic energy (air at a flow rate).  It also provided signals to the electrical system (for feedback and control) through sensors placed strategically in the air stream.  The reason they are connected is to provide an efficient transfer of the air, while allowing the components to be separated for service or maintenance.  The method used for connection was “threaded fasteners with a compression seal” between the mating surfaces.  Performance, namely a leak free conduit, affects the connection type in that the joint must withstand a severe environment of heat, vibration, automotive fluids, and dirt for extended periods of time.
 The fuel system, as noted above, was also connected to the combustion system and provided mass transfer in the form of fuel to the cylinder through the fuel rail.  The connection was formed by an elastomeric radial seal (not an o-ring) and had physical contact with the combustion system through the injectors, but isolated (cushioned) by the elastomeric seal.  Threaded fasteners were used only to prevent the component from being vibrated or ejected out of position.  The reason for this connection is primarily to prevent fuel leaks while allowing for some flexibility in the connection.  This system is essential to the operation of the engine, so performance is critical.  The sealing system appears to be very robust in that it was simple, but a very positive connection.
 The cooling system is connected to the combustion system indirectly through the crankcase.  It is also connected indirectly to the lubrication system in the same fashion.  It is connected to the electrical system through a sensor.  The system primarily allows for the flow of mass (coolant) which also absorbs energy from the metal surfaces as it passes over them.  When looking at the connection at the water pump, a flange & gasket are used to seal the connection.  When looking at the coolant tube connection, an o-ring seal is used with 2 bolts.  Why is this?  The pump has to withstand a significant load from the pulley and justifies the sturdy flange and gasket connection.  The cooling tube, since there are no forces on it, has the o-ring seal, which is much less robust.  The performance effects are that, without cooling, damage to the primary function could occur.  Sealing and connection is critical.
-The next subsystem is the exhaust and was connected to the combustion system with threaded fasteners using a compression seal.  They are connected in this fashion to allow for the transfer of mass & energy, in the form of exhaust, while allowing service & maintenance.  Information is also transferred to the electrical system in the form of voltage from the oxygen sensor to provide feedback for control of the engine. Performance affects the seal of this system in that a leak of exhaust gases would not critically affect the operation, but degrade the efficiency/effectiveness.
+''Exhaust System''
 The fifth subsystem is the Lubrication system, which directly and indirectly connects to the combustion system.  The indirect connection is by way of heat transfer from the metallic surfaces to the lubricant as it comes in contact with all of the moving (and many non-moving) parts in the crankcase, valve housing, and cylinder head.  Some mass transfer to the oil, in the way of gases and small particles occurs, through very small leaks from the combustion system. Also, the direct flow of small amounts of lubricant to the cylinder also occurs (an unwanted connection), but it does find its way in because of the nature of the piston ring sealing mechanism used to separate the two subsystems.  This seal is a metal to metal seal formed by piston ring being oversized to the cylinder bore causing pressure between the two very smooth surfaces.  This allows for motion of the piston while minimizing the transfer of material between the two systems.
 Electric & Spark subsystem is connected to combustion system, the intake system, the lubrication system, and the exhaust system.  Each has an energy transfer, of one kind or another, and in many cases, also a signal or information transfer, via sensor.  The energy transferred directly to the spark plug initiates the combustion reaction as the electric energy is dissipated as light and heat in the cylinder. The connection to the cylinder is through the threaded body of the spark plug and sealed by a compression ring.  This provides a seal that will contain the pressures seen in the piston and allows for the proper grounding of one of the poles of the spark plug, while insulating it from the other pole.  The performance affect of this seal is also critical in that a loss of pressure will degrade or negate the operation of the engine, but still must provide for service or maintenance.  This is a critical seal.  For each of the sensors, the sealing is usually to provide protection from whatever fluid is being sensed, whether it be air, oil, exhaust, or coolant.  Oil, water, and air have o-ring seals with threaded fasteners, while the exhaust is welded permanently in place.  O-rings provide seals with minimal leak while allowing for service.  The connection at the exhaust is permanent, clearly to ensure no leak, regardless of service.
 The Motion Translation Subsystem is the basis of which all the other subsystems form their location or orientation because it is what provides the energy to operate the other systems. It is connected to the combustion system through the pistons & piston rods, fuels system through the fuel pump, the coolant system through the water pump and cooling circuit, the lubrication system through the oil pump along with the various ports and channels.  Some contact also occurs with the moving components causing splash, and the electrical system is connected through the alternator and receives signals from the rpm sensor. Each is physically connected and involves a transfer of energy of some kind.  The “reason why” they are connected is to facilitate this energy transfer and the manner in which they are connected is by pulley & bearing components with the exception of the lubrication system.  The lubrication system not only has a pump, but also depends on a “splash” type of distribution caused by the moving components that are bathed in lubricant.  The performance influences this subsystem in that it is the source for the other subsystems to be powered.  Connection, sealing, and interaction all play critical roles, for example, lubrication; all moving parts have to be in contact with the lubricant system in some way to reduce friction and transfer heat.
 The interconnection of subsystems are affected by global factors in that the manufacture & recycle-ability of each of the components have standards for each country, that if not managed properly or with sensitivity, will limit the markets to which it can be made available.  Societal factors include the emissions of the engine, so as to not be detrimental to the overall population, and met US requirements.  Along the same lines, environmental factors influence the treatment of waste from the manufacture, the resources used to create the components, and the materials depleted in the process.  Since the majority of the components are metals, a very high percentage are recyclable, which is very positive for the environment.  Economic factors influenced the connections of the components by limiting the cost of these connections and creating a balance between the money spent and the effect of proper connection (or improper connection).  This is pointed out in the subsystem paragraphs, but in general, this is accomplished by minimizing the number of fasteners or through the use of inexpensive materials.

@@ Line 181: / Line 181: @@
 ''Advantages''
-:1) Unlike the OHV (Overhead valve) engine, a SOHC (single overhead camshaft) engine uses the camshaft to control the valves above           :the cylinders. At higher rpm’s the valve timing is almost perfect because as the camshaft rotates it moves the valves up and down. The alternative also has a lower inertia on its valve since it does not require extra components such as lifters, pushrods, and rocker arms to control valve timing. Also, SOHC engines have the capability to install three to four valves per cylinder, while OHV engines can only have two valves per cylinder due to the difficulty in implementing new technologies. This particular engine has twelve valves compared to the eight on the GM engine. Better timing improves the quality of the air mixture in the combustion chambers as well as the overall efficiency of the engine.
+:1) Unlike the OHV (Overhead valve) engine, a SOHC (single overhead camshaft) engine uses the camshaft to control the valves above           the cylinders. At higher rpm’s the valve timing is almost perfect because as the camshaft rotates it moves the valves up and down. The alternative also has a lower inertia on its valve since it does not require extra components such as lifters, pushrods, and rocker arms to control valve timing. Also, SOHC engines have the capability to install three to four valves per cylinder, while OHV engines can only have two valves per cylinder due to the difficulty in implementing new technologies. This particular engine has twelve valves compared to the eight on the GM engine. Better timing improves the quality of the air mixture in the combustion chambers as well as the overall efficiency of the engine.
 :2) The true advantage of the 4.3L V6 is more power and torque.  While the 4 cylinder only had 120 hp and 140 ft-lbs of torque the V6 had (depending on model year) as much as 195 hp and 250 ft-lbs of torque.  This power and torque advantage increased GM small truck’s overall performance.  The larger engine increased GM’s small truck towing and cargo capabilities.  Also, by increasing power GM’s small trucks were faster than their 4 cylinder counter parts.

@@ Line 171: / Line 171: @@
 :Maintenance is the process of keeping a product in good working order, which is key to keeping an engine running properly. The performance of the engine is a process that can degrade over time and does require proper maintenance to continue operation. The system is not frictionless and there is motion so there is energy expended into the engine that causes wear on parts. This wear should be regularly checked through maintenance and repair. As implied and stated previously, neither the repair nor maintenance can be an easy or intuitive process. This is evident in the entire field of auto-mechanics who cater to doing maintenance and repair on engines for the average user who is unsure of what to do or lacks the tools required.
-===Alternative Profile===
+===Alternative Profiles===
 ''Alternative Engines''
-:2)Because GM also used this 2.2L inline 4 cylinder engine in its small trucks, such as the Chevy S-10/GMC Sonoma, the optional 4.3L V6 was a direct alternative.
+:1) A similar alternative is the Mazda F2 2.2L SOHC engine used in the Ford Probe and Mazda MX6.
 ''Advantages''
-:2)The true advantage of the 4.3L V6 is more power and torque.  While the 4 cylinder only had 120 hp and 140 ft-lbs of torque the V6 had (depending on model year) as much as 195 hp and 250 ft-lbs of torque.  This power and torque advantage increased GM small truck’s overall performance.  The larger engine increased GM’s small truck towing and cargo capabilities.  Also, by increasing power GM’s small trucks were faster than their 4 cylinder counter parts.
+:1) Unlike the OHV (Overhead valve) engine, a SOHC (single overhead camshaft) engine uses the camshaft to control the valves above the cylinders. At higher rpm’s the valve timing is almost perfect because as the camshaft rotates it moves the valves up and down. The alternative also has a lower inertia on its valve since it does not require extra components such as lifters, pushrods, and rocker arms to control valve timing. Also, SOHC engines have the capability to install three to four valves per cylinder, while OHV engines can only have two valves per cylinder due to the difficulty in implementing new technologies. This particular engine has twelve valves compared to the eight on the GM engine. Better timing improves the quality of the air mixture in the combustion chambers as well as the overall efficiency of the engine.
 ''Disadvantages''
-)While the larger V6 produced more power and torque, it came at the cost of fuel efficiency and purchasing price.
+:1) SOHC engines require certain timing belts or chains with similar components to keep the camshaft running. This alternative is much more complex than the OHV engine due to the different components and the positioning of the camshaft. It is also much more expensive because of the complex parts.
 :1)The GM 2.2L OHV engine has a horsepower of 120 hp at 5000 rpm, while the Mazda F2 SOHC engine has a horsepower of 110 hp at 4700 rpm. Also, the OHV engine has a torque of 140 ft-lb at 3600 rpm and the SOCH engine has a torque of 130 ft-lb at 3000 rpm. Even though the SOHC is more complex and has twelve valves compared to the 8 valves in the OHV, the OHV engine out performs the SOHC in terms of horsepower and torque.
@@ Line 194: / Line 198: @@
 ''Cost Differences''
 :1)Since the GM OHV comes from a 94’ S-10 and the Mazda SOHC comes from  91’ Ford Probe and 92’ Mazda MX6, these engines can only be bought used (refurbished). The Mazda engine costs $2180.00 while the GM engine costs $1400 .00. The big difference in the prices is the complexity of the Mazda engine. The OHV is a much more simple and durable engine than the SOHC so it costs less.

@@ Line 173: / Line 173: @@
 ===Alternative Profile===
-''Alternative Engine''
+''Alternative Engines''
-:A similar alternative is the Mazda F2 2.2L SOHC engine used in the Ford Probe and Mazda MX6.
+:1)A similar alternative is the Mazda F2 2.2L SOHC engine used in the Ford Probe and Mazda MX6.
 ''Advantages''
-:Unlike the OHV (Overhead valve) engine, a SOHC (single overhead camshaft) engine uses the camshaft to control the valves above the cylinders. At higher rpm’s the valve timing is almost perfect because as the camshaft rotates it moves the valves up and down. The alternative also has a lower inertia on its valve since it does not require extra components such as lifters, pushrods, and rocker arms to control valve timing. Also, SOHC engines have the capability to install three to four valves per cylinder, while OHV engines can only have two valves per cylinder due to the difficulty in implementing new technologies. This particular engine has twelve valves compared to the eight on the GM engine. Better timing improves the quality of the air mixture in the combustion chambers as well as the overall efficiency of the engine.
+:1)Unlike the OHV (Overhead valve) engine, a SOHC (single overhead camshaft) engine uses the camshaft to control the valves above the cylinders. At higher rpm’s the valve timing is almost perfect because as the camshaft rotates it moves the valves up and down. The alternative also has a lower inertia on its valve since it does not require extra components such as lifters, pushrods, and rocker arms to control valve timing. Also, SOHC engines have the capability to install three to four valves per cylinder, while OHV engines can only have two valves per cylinder due to the difficulty in implementing new technologies. This particular engine has twelve valves compared to the eight on the GM engine. Better timing improves the quality of the air mixture in the combustion chambers as well as the overall efficiency of the engine.
 ''Disadvantages''
-:SOHC engines require certain timing belts or chains with similar components to keep the camshaft running. This alternative is much more complex than the OHV engine due to the different components and the positioning of the camshaft. It is also much more expensive because of the complex parts.
+:1)SOHC engines require certain timing belts or chains with similar components to keep the camshaft running. This alternative is much more complex than the OHV engine due to the different components and the positioning of the camshaft. It is also much more expensive because of the complex parts.
 ''Performance''
-:The GM 2.2L OHV engine has a horsepower of 120 hp at 5000 rpm, while the Mazda F2 SOHC engine has a horsepower of 110 hp at 4700 rpm. Also, the OHV engine has a torque of 140 ft-lb at 3600 rpm and the SOCH engine has a torque of 130 ft-lb at 3000 rpm. Even though the SOHC is more complex and has twelve valves compared to the 8 valves in the OHV, the OHV engine out performs the SOHC in terms of horsepower and torque.
+:1)The GM 2.2L OHV engine has a horsepower of 120 hp at 5000 rpm, while the Mazda F2 SOHC engine has a horsepower of 110 hp at 4700 rpm. Also, the OHV engine has a torque of 140 ft-lb at 3600 rpm and the SOCH engine has a torque of 130 ft-lb at 3000 rpm. Even though the SOHC is more complex and has twelve valves compared to the 8 valves in the OHV, the OHV engine out performs the SOHC in terms of horsepower and torque.
 ''Cost Differences''
-:Since the GM OHV comes from a 94’ S-10 and the Mazda SOHC comes from  91’ Ford Probe and 92’ Mazda MX6, these engines can only be bought used (refurbished). The Mazda engine costs $2180.00 while the GM engine costs $1400 .00. The big difference in the prices is the complexity of the Mazda engine. The OHV is a much more simple and durable engine than the SOHC so it costs less.
+:1)Since the GM OHV comes from a 94’ S-10 and the Mazda SOHC comes from  91’ Ford Probe and 92’ Mazda MX6, these engines can only be bought used (refurbished). The Mazda engine costs $2180.00 while the GM engine costs $1400 .00. The big difference in the prices is the complexity of the Mazda engine. The OHV is a much more simple and durable engine than the SOHC so it costs less.
 *There are also V6 and V8 engines that offer much more power than our product, but they have a poor fuel economy.

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 '''Difficulty scale'''
-:Assembly difficulty will be measured by three main factors; time taken, mental/knowledge requirement, and physical demand. A part may be considered difficult if it takes a large chunk of time to attach, requires a great deal of strength to take off, or if the process requires a great deal of thought beforehand. Depending on the part, a combination of these factors will be required to assemble the component properly. The scale is listed below:
+:Assembly difficulty will be measured by three main factors; time taken, mental/knowledge requirement, and physical demand. A part may be considered difficult if it takes a large chunk of time to attach, requires a great deal of strength to connect, or if the process requires a great deal of thought beforehand. Depending on the part, a combination of these factors will be required to assemble the component properly. The scale is listed below:
 ::1- Less than 5 minutes to complete, physical & mental effort is minimal, and requires no special tools (something other than the contents of a typical home tool box; screwdriver, pliers, etc.)

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 ''Complexity Scale''
-:Simple = volume < 10 in3, with 1 or 2 process steps
+:Simple = The volume is less than 10 cubic inches and requires 1 to 2 process steps to manufacture
-:Moderate = < 20 in3, 2 to 4 operations
+:Moderate = The volume is less than 20 cubic inches and requires 2 to 4 operations to create
-:Complex = < 30 in3, 5 or more operations
+:Complex = The volume is less than 30 cubic inches and requires 5 or more operations to manufacture
 ::These can each be modified if new technology is part of the process or if a new application of an existing process is identified.  If the precision of the part exceeds capabilities of the available supplier base, add 1 rating level.
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 :In summary, the attributes for these components have been discussed, evaluated, and enumerated in plain terms that help to provide an understanding of decisions that went into the development and formation of those attributes.
 ===Solid Modeling===
 Below are the solid modeling constructions of the piston assembly. These parts were chosen to be modeled because their importance to the engine as a whole. When broken down even the simplest of engines have pistons, so our team feel that it is a good place to start when analyzing a product such as this. The piston assembly is also one of the most recognizable parts of the engine. This helped us in the modeling phase because there was already a basic understanding of the part where as so other parts are not as easily understood.