Group 20 - GM V6 Engine - 1

Executive Summary

This project was to take the students and break them into product design teams. These teams were then given a product that they were to disassemble, observe possible problems, then reassemble the product. Each group was to be recording all of their steps and observations of the different components along the way as well. These observations and recordings are put forth in this Wiki page.

Introduction

Group Members

• Nicholas Stanley - Group 20 Leader
• Matthew Filion - Group 21 Leader
• Kyle Clair
• Jason Martz
• John Northrup
• James Trzaskos
• Michael Alcazaren
• Matthew Ormandy
• Brad Matthews
• Anselme Payen

Product

• Manufactured by: General Motors
• Product: Vortec 4300 V6 Engine
• Class: 90° 'V' Class 6 Cylinder
• Displacement: 4.3 Liters
• Manufactured in: Tonawanda, New York and Romulus, Michigan

Before Disassembly

Purpose and How it Works

The gasoline engine is used to convert chemical energy in the form of a gasoline and air mixture to mechanical energy, which is used to make a vehicle move. The engine generates this energy by the use of a combustion cycle obtained through a piston – cylinder system which is attached to the crank shaft. The piston moves down letting an Air/Gasoline mixture enter the cylinder then the piston rises compressing the mixture. Then the spark plug ignites creating a small explosion which drives the piston down to keep the cycle moving and releases the exhaust. This constant cycle is rotating the crank shaft which eventually relates this energy to turn the tires.

Types of Energy

Our GM V6 engine uses gasoline which contains a total chemical energy. Within this total chemical energy is a certain amount of useful energy which is taken in the form of kinetic energy. The kinetic energy is used to produce the work needed in turning the crankshaft.

Number of Parts

Estimated Total Number of Parts: 400 – 500

This number that we came up with is a combination of the few main parts of the engine along with all of the nuts and bolts.

Types of Material

We concluded that there are primarily four types of material used in this engine. These are Steel, Plastic, Rubber, and Aluminum. We concluded that these are primarily the four types because the different materials contain different alloys and types due to what the use is in the engine.

Disassembly Procedure

Step	Part Name	Disassembly Discussion	Other Notes
1	Throttle Body	Removed 2 - 10mm screws and bolts	****
2	Intake Manifold Cover	Removed 8 - 10 mm screws and bolts	****
3	Spark Plug Coil Pack	Removed 2 - 10 mm bolts and screws, Part was removed from top of engine	****
4	Central Fuel Injector	Removed 1 Torque bolt with a T30 wrench	****
5	Distributor rotor	Untwisted from gear and removed, no bolts holding this part on	Easy to Remove, No Bolts
6	Upper Radiator Hose Connector	Removed 2 - 10 mm bolts	****
7	Exhaust Gas Recirculation Valve (EGR)	Removed 1 - 10 mm bolt (bottom) and 1- 1/2 in bolt (top)	****
8	Intake Manifold	Removed 8 - 1/2 in bolts, Part was removed from top of engine	****
8A	Thermostat	Removed without any bolts, was resting in intake manifold	Easy to Remove, No Bolts
9	Crank Shaft Pulley	Removed 3 - 9/16 in bolts, Part was removed from front of engine	****
10	Water Pump Pulley	Removed 4 - 10 mm bolts	****
11	Water Pump	Removed 3 - 9/16 in bolts	****
11A	Water Pump Back Plate Cover	Removed 6 - 10 mm bolts	****
-	Timing Chain Cover	Removed 3/8 in bolts, Top left was a broken bolt, middle left and right bolts have extension (longer)	This was not removed due to other parts not able to be removed
12	Engine Mounts (Left and Right)	Removed 3 - 9/16 in bolts from each side, Right Mount has damper attached	****
13	Oil Cooler Adapter	Removed 2 - 1/2 in bolts	****
14	Oil Pan	-	****
15	Oil Pickup	Removed 4 - 10 mm bolts	****
16	Oil Pump	Removed 1 - 5/8 in bolt	****
17	Oil Pressure Sending Unit	Untwisted from top of engine towards the back	Easy to Remove, No Bolts
18	Rocker Arms and Push Rods	Removed 11 - 13 mm bolts, (6 right, 5 left), 1 - 14 mm bolt removed from left side of engine	****
19	Cylinder Head Cover (Left and Right)	Removed 13 - 1/2 in bolts (6 - silver on bottom, 2 - short black in corners, 5 - long black in middle), No head gaskets were on the engine	****
20	Engine Mount Bracket	Used vice grips to remove 2 bolts	****
21	Connecting Rod Caps	Removed 12 - 14 mm bolts (There were 6 connecting rod caps each with 2 bolts per cap)	Took Some coaxing to remove these due to the engine being seized up making it hard to reach some bolts
22	Crank Shaft Caps	Removed 2 - 5/8 in bolts from each (triangle on caps goes towards left side of engine)	****
23	Rear Main Cap	Removed 2 - 5/8 in bolts	****
24	Drive Plate	Removed 6 - 14 mm bolts	Difficult to remove due to the location of some bolts
25	Piston	Removed using a mallet and some screw drivers	Once the connecting rod caps were removed we were able to remove the pistons, these were difficult to remove because of the angles they were at and the cylinders were very beat up so the pistons did not slide properly

**** these bolts or parts were all easy to remove, some could be hand loosened, the only difficulty was finding the proper wrench size to fit the bolts because some were in metric while others were in english

After Disassembly

Part Number	Part Name	Quantity	Material	Manufacturing Process	Function	Picture
1	Throttle Body	1	Cast Aluminum	Cast	Controls the amount of air that flows into the engine
2	Intake Manifold Cover	1	Composite Plastic	Injection Molding	Protects the intake manifold from any foreign substances
3	Spark Plug Coil Pack	1	Iron & Aluminum	Cast	Determines when and which spark plugs spark
4	Central Fuel Injector	1	Plastic Body Nylon Hoses Aluminum Regulator	injection mold injection mold cast	6 injectors in one body, each with valves that open to allow the pre-pressurized fuel to flow into the proper intake ports. This type of fuel injection is called Central Point Sequential Injection
5	Distributor rotor	1	Plastic Top Cast Iron Shaft	Injection Molded Top Cast Shaft	Rotates synchronously with the camshaft, and sends information to the coil pack so it can fire each individual spark plug as the distributor rotates
6	Upper Radiator Hose Connector	1	Iron	Cast & Machining	Transfer the coolant from the radiator to the engine
7	Exhaust Gas Recirculation Valve (EGR)	1	Iron & Aluminum	Cast	Regulates the recirculation of the engines exhaust back to the intake
8	Intake Manifold	1	Cast Aluminum	Cast	Evenly distributes air to intake ports in the cylinder heads. Contains passageways for fuel delivery to intake ports.
8A	Thermostat	1	Iron	Cast	Regulates temperature of coolant. Opens when hot to allow coolant to flow to radiator.
9	Crank Shaft Pulley / Harmonic Balancer	1	Iron	Cast	Takes rotational energy from the crankshaft to drive a serpentine belt to power other car accessories (Alternator, etc) Also dampens torsional vibration
10	Water Pump Pulley	1	Iron	Cast	With a rubber belt attached, transfers power from crankshaft to the water pump
11	Water Pump	1	Iron & Brass	Cast & Machining	Circulates coolant throughout the engine and the rest of the cooling system
11A	Water Pump Back Plate Cover	1	Steel	Stamped	Prevents coolant from leaking out of pump
12	Engine Mounts (Left and Right)	1 each side	Iron	Cast	For mounting the engine in the vehicle's engine bay and absorb vibration
13	Oil Cooler Adapter	1	Aluminum	Cast	Connection for an external oil filter
14	Oil Pickup Tube and Filter	1	Aluminum	Cast	Filters and allows oil to flow from bottom of oil pan to oil pump
15	Oil Pump	1	Steel	Cast	Circulates oil throughout the engine
16	Oil Pressure Sending Unit	1	Iron Plastic	Cast Injection Molding	Sends information to oil pressure gauge or low oil pressure light
17	Rocker Arms and Push Rods	6 each side	Composite	Process	Push rods transfer rotational mechanical energy from camshaft to rocker arms Rocker arms push down valves to open them
18	Cylinder Head Cover/ Valve Cover(left and right)	1 each side	Composite Plastic	Injection Molded	Prevents oil from exiting the engine and debris from entering. Contains breathers for air from blow-by to escape. One of the breathers routes to the positive crankcase ventilation valve for recirculation into the intake. One of the covers also contains the oil filler neck.
19	Engine Hanger	1	Iron	Cast	Provision for removing engine from the vehicle's engine bay.
20	Connecting Rod Caps	6	Iron	Cast	Connect the connecting rod to the crankshaft via the crankpin journals. Journal bearings are inserted for smooth operation.
21	Crankshaft Caps / Main Caps	3	Iron	Cast	Hold the crankshaft to the block via the main journals. Journal bearings are inserted for smooth operation.
22	Rear Main Cap	1	Iron	Cast	Mounting of the oil pump
23	Drive Plate / Flywheel	1	Iron	Cast	Storage of rotational energy
24	Oil Pan	1	Aluminum	Cast	Storage of oil to be circulated
25	Piston	6	Iron	Cast	Transfers the force created by the combustion reaction to piston rod then to the crankshaft
25A	Connecting Rod	6	Iron	Cast	Connects the piston to the crankshaft, transfers forces
25B	Compression Ring	12 total, 2 per piston	Aluminum	Cast	Create a pressure seal between the piston and cylinder walls so adequate compression can be produced
25C	Oil Ring	6 total, 1 per piston	Aluminum	Cast	Prevents oil from entering the combustion chamber
26	Engine Block	1	Cast Iron	Cast	Houses the pistons and other working parts
27	Crankshaft	1	Iron	Cast	Takes the linear energy created by the pistons and translates it into rotational energy
28	Camshaft	1	Iron	Cast	The lobes on the camshaft press tappets which raise the pushrods against the rocker arms to open the valves
29	Balance Shaft	1	Iron	Cast	Has weights which cause a vibration to cancel out that caused by the 90 degree cylinder banks.
30	Timing Chain	1	Rubber	Injection Molding	Connects the the crankshaft, camshaft, and balance shaft so that they all spin at the correct speeds.
31	Timing Chain Cover	1	Composite Plastic	Injection Molded	Acts as a guard to keep debris away from the timing chain
32	Cylinder Heads	2	Iron	Cast	Each house rocker arms and valves for delivery of fuel and air into the combustion chambers. The top of each combustion chamber is provided by the cylinder head.
33	Headgaskets	2	MLS - Multiple Layer Steel or Copper	Cast	Create seals between the block and cylinder heads so necessary compression can exist and oil and coolant can flow in their respective passageways.

Sensors

Part Number	Part Name	Quantity	Function
1	Throttle Position Sensor	1	Used to determine load on engine
2	Crankshaft Angle Sensor	1	Used to determine which cylinders to deliver fuel to
3	Oxygen sensor	1 on engine	Used to determine the amount of oxygen in the engine's exhaust. This tells the ECU if the engine is running lean/rich so it can make fine adjustments to the amount of fuel delivered.
4	Intake Manifold Absolute Pressure Sensor	1	Used to determine amount of air entering engine.

CAD: Parts and Assembly

Piston in AutoCAD

Assembly

Assembly of the Product was reverse order of disassembly. The difficulties that were faced were dealing with the pistons. One problem encountered during assembly with the pistons was fitting them back in the cylinders. The compression rings on the pistons needed a special ring compressor to make it so they could be fitted into the cylinders. The problem here was that the tool needed was broken therefore requiring our group to be innovative and use two screwdrivers and compress the rings that way.

After Assembly

• Clearly explain how your product works now that you have seen its component structure. Does your product run the same as it did before you disassembled it?

How it Works

Process

The internal combustion engine, such as the General Motors V6 Vortec 4300 engine, works by transferring the chemical energy in gasoline into mechanical energy to move the vehicle. To complete this process, a basic 4 stroke cycle called the Otto Cycle. The four cycles of this process are as follows:
1.) The Intake stroke - In this stroke of the process, the piston is lowered, and the chamber or cylinder is filled with a fuel/air combination which is determined by the throttle.
2.) The Compression stroke - In this stroke, the piston is raised up while the openings on the cylinder head are closed, in order to compress the fluid to its desired compression to get ready for the next stroke.
3.) The Ignition stroke - Here the fluid is ignited by a spark plug, and the piston is forced down.
4.) The Exhaust stroke - In the final stroke of the cycle, the opposite intake opens and the byproduct (exhaust) is released.
This process occurs in a few main components located inside of the engine.

The Otto Cycle:

Main Components

• Engine Block - The engine block is the main part of our engine, and in just about every other internal combustion engine. The GM V6 Vortec 4300 has an engine block constructed out of cast iron, which is then machined to include the other parts attached to it. One of the most important machined parts of this engine are the bored out holes that take the form of cylinders. Here in these cylinders, the pistons are found. Other parts directly connected to the engine block are the cylinder heads, crankshaft, and the engine mounts.

The most critical process of an engine occurs here in the engine block inside of the cylinders. The insides of these cylinders must be machined to a very low tolerance so the least amount of friction between the piston and the cylinder wall can occur. Inside the cylinder is where the Otto cycle occurs. This process occurs hundreds of times per minute, and these mini-explosions require the engine block to be very sturdy. Because of this process occurring very rapidly, a potential for overheating can occur. This overheating can lead to cracking of the engine block, and failure of the engine. To combat this, there is a space just outside of the cylinder walls where a fluid from the radiator is pumped through to keep it at temperature.

• Pistons - The pistons in the engine act as the compressing object to compress the fuel/air mixture to its desired volume before a spark sets of the explosion. The pistons contain 3 rings which are necessary for proper sealing of the system, but allows for the piston to be moved freely. The rings of the pistons seal off the top side, allowing for proper compression, and the bottom allows for no lubricants from the bottom to come up into the chamber and be burned. An automobile that is said to be burning oil, could very well have cracked, faulty, or worn rings allowing the oil to be burned with the fuel/air mixture. The pistons are connected to the crankshaft via connecting rods. These rods are able to rotate on a hinge like axis, to transfer the mechanical forces to the crankshaft.

• Crankshaft – In order for the Otto cycle to be called a cycle, it needs to be able to be repeated. The crankshaft connects all of the pistons in a predetermined order called the firing order, so that depending on the number of cylinders, each cylinder will be going through a different part of the cycle. For example, a firing order of 1-6-5-4-3-2, would mean the first cylinder to fire would be the 1 cylinder, which would turn the crankshaft just a enough so that the 6th cylinder was in the firing position, which in turn, turns the crankshaft a little bit more and the fifth cylinder fires, and so forth until all fuel has been used up or the engine is stopped. To make an efficient crankshaft, the less vibration the better, and seen on our crankshaft there are counterweights to reduce vibration in the engine.

• Camshaft – Another critical part of the engine is the camshaft. The cam shaft is designed to open each cylinder’s respective valves at the appropriate times. On one cylinder, one valve must open and the other must be closed, either the fuel/air mixture valve or the exhaust valve. Because the cylinders are firing at different times, the cam shaft has to be engineered to open each valve at the right time, and is in time with the crankshaft. The crankshaft works by being rotated and little parts of it above each valve open either open the valve or close it at the exact moment.

Here is a working image showing how the general process occurs in a V6 engine. The pistons are gray, push rods blue, crankshaft green, and this whole system rests inside of the engine block (partly shown as a grid on one side). The cylinders are all connected to the crankshaft at certain points to allow for a smooth cycle.

V6 Engine Model

Main Systems

Our engine contained components of some main systems of the vehicle. Although the full systems were not present on our engine, we felt it necessary to represent the system as it works on the vehicle for an understanding of why these components are present on the engine.

•Fuel Delivery - In order for combustion to occur, fuel and air must enter the engine during the intake stroke of each cylinder. Fuel system components on the vehicle include the ECU, gas tank, fuel pump, and high-pressure fuel send and return lines. The fuel pump creates enough pressure in the system for injection. The fuel lines reach the central fuel injector, which is really six injectors together. This injector is basically a series of valves that receives information from the Engine Control Unit(not a component of our engine but a component of the vehicle) so it can open the correct valves at the correct times. When the injector allows fuel to flow through, it goes through a tube that leads through the intake manifold to the correct intake port in the cylinder head.
The most important part of the fuel system is the ECU because it determines when and how much fuel to inject by opening the valves in the fuel injector. To maintain the proper air/fuel ratio sensors must be utilized to determine how much air is entering the engine and how much fuel is required. The throttle position sensor determines the load on the engine, and the oxygen sensors determine if it is running rich or lean, for fine adjustments. The crankshaft angle sensor tells the ECU what stroke each piston is in so that fuel can be added at the appropriate time. The Intake Manifold Absolute Pressure Sensor determines how much air is entering the engine.

•Ignition - Our engine uses an electronic ignition system with a distributor. The distributor spins with the crankshaft and sends a signal to the coil-pack. The coil pack sends a spark to the spark plug via spark plug wires. Since the distributor is in alignment with the crankshaft, spark is delivered at the correct time. The firing order of our engine is 1-6-5-4-3-2.

•Lubrication - In order to operate properly, any engine needs lubrication. Our engine did not contain any fluids, but in order to function it needs motor oil. Motor oil haas many functions. It lubricates to reduce friction and wear, absorbs shock to reduce wear, cools, cleans, and inhibits oxidation for the prevention of rust. Without proper lubrication, engine components will fail rather quickly. If for example a car was traveling at 55 mph and a hole in the oil pan developed and all oil was drained in a matter of one minute, the engine would seize in just over a minute and catastrophic engine damage would occur.
Oil is added through a fill neck on one of the valve covers and sits at the bottom of the oil pan before entering the oil pickup tube which has a strainer on the end so that foreign particles are not circulated. After entering the pickup, it goes through the oil pump which pumps it through passageways in the block to squirters that deliver it to moving components. It also flows to an external oil filter that is changed approximately every 3,000 miles with the oil, so that fine particles stay away from moving components.

•Cooling - The cooling system contains a water pump driven by the crankshaft to circulate a mixture of water and anti-freeze through passageways in the engine and the radiator. The thermostat contains wax which expands when heated so that it opens when the coolant is hot, allowing it to flow to the radiator for cooling by wind or fans. The radiator cap keeps the system under pressure so that the boiling point of the coolant is increased.

Functionality

The functionality of our given engine was non-working when first received and after reassembly, the engine was once again non-functioning. The engine was non-functioning due to other necessary parts missing, such as components for transferring fuel and coolant. Regardless of the required missing parts, the engine would not have worked successfully. A few of the main parts were noticed to be cracked from possible over tightening of bolts, and this would result in dangers while attempting to start and possibly running the engine. There were also no headgaskets, so necessary compression would not be possible.

• Explain how analyses could be used to design and test your product (or some of its components). What type of basic engineering models could be used? Could you use estimates or would you need very precise models?

• Reflect on the disassembly/assembly processes. Were they the reverse of one another? Why or why not? Were the same sets of tools used? Were you able to reassemble the entire product? Why or why not?

• What design changes would your group recommend at the product level (operation, manufacturing, assembly, design, configuration, etc.)? What new features would you recommend? Would you recommend a different shape, configuration, layout, style?

• What recommendations would your group make to the company who designs and makes this product with regard to its design, manufacture, use, maintenance, and recycle?

Improvements

A general rule of thumb for a car, is the lighter it is, the more fuel efficient it will be. To improve on the general efficiency of the entire car and get more miles to the gallon, different materials could be used for certain applications. These materials would be just as strong, but much lighter, cutting unnecessary weight from the engine.

• Create the engine block out of aluminum instead of cast iron. The engine block is one of the largest and heaviest components of the engine, and a switch to a less dense material such as aluminum. This aluminum would need to be developed to withstand the forces and heat created inside of the engine. While switching out the engine block, other cast iron components such as cylinder heads could be replaced as well. This would result in a reduction of weight, and an increase in efficiency. Also, Aluminum is less corrosive, meaning it will survive longer.

• Change the angle of the cylinders from 90˚ to 60˚. The angle of 90˚ is the most efficient angle for a V8 (8 cylinder) engine, but V6 engines can be configured to run this way. Our V6 was made with a 90˚ angle because it is made in the same factories as V8 engines and it is economical to just configure the V6 at 90˚ so they can be made in a similar way. However, the most efficient angle for a V6 is 60˚. This angle change is significant, as the engine can be made more compact, and this configuration is where the least amount of vibration occurs.

• Use all metric fasteners. The fasteners used in this engine were not all the same system. Some were English, come were Metric. For assembly and disassembly purposes, or even upgrading and maintain the engine, it would be easiest if one whole system was used, and metric is used in all but 3 countries, which makes it the most sensible to use.

• Use multi-port injection instead central-port injection. The engine currently uses central-point injection where a central injector to allows fuel through the intake manifold with tubes into each individual intake port. The central injector is really six injectors put together so that the fuel can be delivered sequentially. With a multi-point fuel injection system, there is an injector at each intake port for more direct delivery.

Group Contributions

• Nicholas Stanley - Group 20 Leader
main assembler, one of main dissassemblers, proofreading and contributing to wiki, presentation consultant

• Kyle Clair
wiki, references

• Jason Martz
wiki, worked on table

• John Northrup
wiki

• James Trzaskos
CAD, One of the main disassemblers/assemblers, presentation, 9/16 wrench operator

• Matthew Filion - Group 21 Leader
With prior automotive knowledge and experience, was one of the main contributors to the disassembly/reassembly and group organization. Also provided presentation consultation, research, and wiki contribution and proofreading, especially of the functions of the components and main systems.

• Michael Alcazaren
Was one of the main organizers of the wiki along with Brad. Contributed to disassembly, communication, and organization of pictures. Created the table.

• Matthew Ormandy
Led photo documentation and worked to assemble/disassemble. Created the presentation with Jay. Worked to organize the group.

• Brad Matthews
Along with Mike, was one of the main organizers of the wiki. A major player during disassembly to help organize and categorize parts. Worked on the table.

• Anselme Payen
Was one of the main disassemblers and assemblers while taking pictures. Contributed to the wiki.

References

Brain, Marshall (2000, April 5th). How Cars Engines Work. Retrieved December 4, 2008, from How Stuff Works Web site: http://auto.howstuffworks.com/engine.htm

Bryanston-Cross, P. (2001). The Otto Cycle. Retrieved December 4, 2008, from Optical Engineering Laboratory Web site: http://www.eng.warwick.ac.uk/oel/courses/engine/ic018.htm