Group 31 - Honda Engine
The members of this group are students enrolled at the University at Buffalo. They are assigned to this group and this project by the requirements of the course MAE 277, Introduction to Mechanical Engineering, taught by Erich Devendorf.
The project assigned to Group 31 is to dissect, analyze, and reassemble the combustion components of an engine. The transmission components of this engine are to be dissected and analyzed by members of group 19. Research done by George Alessi based on engine numbers found on the engine prior to dissection has revealed the engine to be a 1994 Honda CBR 600 F motorbike engine.
Knowledge of engine operation and construction varies widely in this group. However through this project, the workings of this engine are to be explored and described in a way that would allow for repetition based solely on this report. This wiki page will outline the intended plan, the actual steps taken to dissect and reassemble the engine, and the analysis of Group 31.
The Proposed project of group 31 is outlined below in the following links.
1. Light lifting force.
2. Coordinated lifting force.
3. Use of simple tools.
4. Use of tools and coordinated lifting force.
5. Assorted tool use and careful application of force and spring removal.
>Prior to dissection, the other group assigned to this engine had already disassembled much of the outer components. The components that were already removed were: the valve cover, the camshaft covers, the drive chain, the carburetor, all air intake components and the transmission components.
DIFFICULTY = 1
>The camshafts sitting in place can be lifted out of the engine. Normally they would be held in place by the cam chain, but that had been removed prior to the start of our dissection.
DIFFICULTY = 3
- 10mm Socket
>With one half of the transmission casing removed the crankshaft is fully exposed to the outside.
>8 10mm nuts, 2 per pistons need to removed to extract the crankshaft.
Removing the Pistons Assembly/Separating the Block
DIFFICULTY = 4
- 12mm Allen Key
>The pistons can not be removed from the crankshaft side of engine.
>To get to the pistons the block needs to be separated into two pieces and removed from the middle.
>To separate the crankcase from the cylinder head (separating the block), 10 flange bolts need to be removed using a 12mm Allen key.
>The gasket separating the cylinder head from the crankcase can be removed by hand.
>To remove the cam chain tensioner can be removed by unscrewing the cap nut on the outside of the cylinder head.
>To fully separate everything two other larger flange bolts needed to be removed but no Allen key large enough was present. This was a problem, but not to the extent where it affected the analysis of the engine.
>Once separated, the pistons fall right out of the opposite side of the crankcase.
>Now, the cylinder head, crankcase, crankshaft, camshafts and the piston assembly are all individual pieces.
Dissection of Piston/Rod Assembly
DIFFICULTY = 2
- Rubber Mallet (if necessary)
>Once out of the cylinder head there is no screw, nut or bolt holding the pieces of the piston in place. When taking out the crankshaft two nuts per rod were removed which also released the piston/rod assembly that was then only being held in by the cylinder walls.
>Pistons consist of a piston, connecting rod, two rod bolts, two connecting rod nuts, two rod bearing halves, a pin, and a two pin bearings.
Now as much of the block as was able to be taken apart was. The intake and exhaust valves were ceased in place so they could not be removed or analyzed further.
DIFFICULTY = 5
- 10 mm socket and ratchet
- 8 mm socket and ratchet
- Phillips Head Screwdriver size 1
- Flat Head Screwdriver size 3/16
**The center two carburetors had many stripped bolts on the casing therefore it was impossible to dissect these pieces. But all the carburetors are the same therefore it did not matter for the purpose of understanding of the part.
>The carburetors were removed from the engine prior to the start of Group 31's dissection.
>The carburetors were removed prior to dissection and consisted of 4 separate carbs connected by 2 rods.
>Remove three phillips head screws that hold the three synchronization springs in the area between the four individual carburetors.
>Separate the four carburetors by removing the two rods holding the four carbs together by unscrewing the two nuts on each end of the rods using a 10mm socket for the upper rod and an 8mm socket for the lower one.
>Using moderate force the carburetors can slide off one at a time.
>As each carb comes off, a two thrust springs pressed between two holders two on each carb need to be removed as well. Caution if not removed by hand the springs may fly off and it is very hard to find.
**Only one carb was dissected because all four are identical.
>To get the float chamber cover off the front of the carb three screws need to be removed using a phillips head screw driver.
>Next the O-ring can be removed by hand.
>Using a flat head screw driver remove the pilot screw.
>Using a phillips head screw driver remove the main jet which releases the needle jet holder.
>Using the point of a phillips head screw driver gently push the float pin out and release the float.
>Once the float is loosened the float valve with be released as well.
>Removing the vacuum chamber cover consists of removing three screws using phillips head screw driver.
>Once cover is off the spring loaded assembly consisting of the diaphragm spring, jet needle holder, o-ring, jet needle holder spring, the jet needle and a washer will all be exposed.
>Last thing to be removed in the carb is the starting enrichment valve assembly. Using a 10mm socket the valve nut can be removed revealing a spring and the starter enrichment valve.
1. Honda Service Manual: 91-94 CBR600F2. Honda Motor Co., LTD., 1993. PDF file.
2. "Honda CBR 600 F(2)R 1994." Motor Bikes. N.p., n.d. Web. 29 Oct. 2009. <http://www.motorbikes.be/en/Honda_CBR_600_F(2)R_1994.aspx>.
|Part||Part Number||Quantity||Other Parts Contained in Assembly||Part Material||Description||Model/Picture|
|Cylinder Head||1||intake camshaft , exhaust camshaft , intake valve assembly, exhaust valve assembly, cylinder head cover breather tube , cylinder head bolt , head bolt washer , cylinder head cover , gasket , cam chain assembly (not dissected) , camshaft holder , 6mm bolt , 9mm bolt , 10mm washer , dowel pin , cap nut , sealing washer , cam chain tensioner slider ||Aluminum machine casting||In an overhead cam type engine like this one, the cylinder head contains many key components as listed above. Part of the combustion chamber is in the cylinder head and the cylinder head in responsible for the entering and escaping of air, fuel and exhaust. Exhaust/inlet passages and ports inside the head, determine a major portion of the volumetric efficiency and compression ratio of an engine.|
|Intake Camshaft||14110-MAL-600||1||cam sprocket , cam sprocket bolt , holder ||Steel die casting and machined||Times the opening and closing of the intake valves to let the air/fuel mixture into the cylinders. This process is accomplished with the use of lobes attached to a rod with a gear on one end. The cam chain is attached to the gear which then spins the camshaft allowing the lobes to push open or keep the intake valves closed.|
|Exhaust Camshaft||14210-MAL-600||1||cam sprocket , cam sprocket bolt , holder ||Steel die casting and machined||Times the opening and closing of the exhaust valves to let the combustion waste products out of the cylinder/ contain the combustion. This is done using the same process as described for the intake camshaft.|
|Intake Valves||14711-MAL-600||8||valve lifter , valve shim , valve cotter , retainer , outer valve spring , inner valve spring , stem seal , inner valve seat , outer valve seat , valve guide ||Alloy die casting||Allows the air/fuel mixture to enter the combustion chamber.|
|Exhaust Valves||14721-MAL-600||8||valve lifter , valve shim , valve cotter , retainer , outer valve spring , inner valve spring , stem seal , inner valve seat , outer valve seat , valve guide ||Alloy die casting||Allows the waste exhaust gases to escape the combustion chamber.|
|Head Gasket||12251-MAL-601||1||none||Layered Pressed Steel||Separates the engine block from the cylinder head. Also creates a seal to keep oil and coolant inside the engine.|
|Engine Block||1||piston assembly, connecting rod assembly, crankshaft assembly, upper crank case bolt (6mm) , sealing washer , lower crankcase bolt (6mm) / (8mm) / (10mm) , lower crankcase , upper crankcase , oil orifice long / short , dowel pin , O-ring ||Aluminum machine casting||The engine block contains the majority of the combustion chamber and all of its components as listed above. The block is a "container" for all of the moving parts inside of an engine.|
|Connecting Rods||13210-MV9-670||4||connecting rod bearing cap , cap nut , connecting rod bearing ||Steel permanent casting||Links the crankshaft to the piston.|
|Connecting rod bearing||13313-MV9-630||8||none||Allows the rod to rotate freely with little friction around the crankshaft while at the same time holding a firm connection.|
|Piston||13101-MV9-670||4||piston pin clip , piston pin , top piston ring , second ring , spacers , oil rings ||Aluminum/silicon alloy casting then machining||The piston has many functions. It compresses the fuel and air mix before combustion, contains the combustion by moving away from it to then generate power and also to push the exhaust gases out of the combustion chamber.|
|Piston Rings||13011-MV9-305||8||top piston ring , second ring ||Steel die casting||Two rings that are secured around the top of the piston. The function of these piston rings are to seal the combustion chamber,support heat transfer from the piston to the cylinder wall and regulate the oil consumption of the engine.|
|Crank shaft||13300-MV9-670||1||none (as far as we took our dissection)||Steel die casting and machined||Attached to the connecting rod that pushes on the crank in different connection points to cause it to rotate during the combustion process. The basic function of this part is to convert the simple up and down movement of the piston/rod into rotational movement that can in turn be used to spin a series of gears until it reaches the ground through the wheels.|
|Carburetor||4||throttle stop screw , carb. insulator band screw , choke cable , throttle cable , carb. breather tube , carb. fuel tube , carb. insulator , screws , air chamber , air intake , O-ring , starting enrichment valve , thrust spring , spring seat , carb. connecting bolt/nut (5mm) [1/2], carb. connecting bolt/nut (6mm) [1/2], synchronization spring , air joint pipe , air vent pipe , fuel joint pipe , dowel pin (5mm) , dowel pin (6mm) , starting enrichment valve cable holder ||Carburetor is simply a device with inlets for fuel and air that combine before entering the combustion chamber.|
- Why were different materials selected for different components? Different materials were selected for different components because of the different processes that each component undergoes. Some components are for aesthetic purposes and others need extreme strength because of the forces put upon them. For instance an air intake does not have much stress at all on it, there fore it can be made cheaply from plastic. But a piston is one of the key components of the engine and is continually exposed to extreme head and pressures therefore it needs to be made of a stronger material, such as a metal alloy. ---- - What forces are applied to the components? o If forces are applied estimate their magnitude - Does the material choice affect the manufacturing process? Certain materials act differently when heated or deformed. Some lose strength, some remain the same and others gain rigidity and strength. For this reason there needs to be different manufacturing processes that take into account the unique properties of the material one is working with. - Does the shape affect the manufacturing process? Shape affects the manufacturing process just as much as what material is being used. For example if you need many small to medium sized parts with specific details a good process to use is die casting. On the other hand if you needed a large, simple part that did not need to be made as much a die cast would be terribly inefficient. The cost making a die cast is expensive and only can benefit a system if the cost is the lowest possible without sacrificing quality. In this example, a large more simply shaped object such as an engine block would be much easier made in a sand cast or something similar. - Why was each manufacturing process chosen for that component - Do any components have a particular shape? Why? - Is the component functional, cosmetic, or a combination of the two? - Why do you think the manufacturing process was chosen for a given component? - How complex is the component?