Group 13 - Gate 2: Product Archaeology

Product Dissection

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Dissection Difficulty Scale

During the dissection there were various steps that required different amounts of work, effort and tools. The difficulty of each step was broken down into three different levels based on a criteria created by Group 13. The different levels of difficulty are described below:

Team 13 Difficulty Table

	Team Members Required	Tools Required	Effort Required	Number of Fasteners Used	Number of Components	Number of Subsystems Involved
Possible Points	1-4	1+	1-3	1+	1+	1+
Scale Criteria	This part of the scale was graded based on the number of team members needed for the step. One point was given for each member that was needed during the process.	In this step one point was given for each tool that was used. There was no cap on the amount of points given during this step. (Note: A socket and its drive counted as to points, considering one drive was used with multiple sockets in some cases.)	The effort scale was based on three different categories of effort, the first being minimal which meant the persons performing the job put no effort in, parts could be connected and assembled with no strength or force needed. The second was moderate effort, meaning that effort was needed but the job only gave moderate resistance and required effort, but nothing strenuous for the team member. The final score for the effort, was maximum, which meant that the step required an extreme amount of force, and parts that were very resistant to fastening. Fasteners required larger amounts of torque and parts were heavy and difficult to align and reassemble. One to three points were awarded for this scale, one, two and three points given respectively for the different amount of effort.	In this step one point was awarded for each piece of hardware used in the reassembly, there was no cap to the amount of points a step could accumulate.	This section of the criteria, points were given for the amount of components that were involved in the reassembly. The points were given for the number of components that were involved in the mating of the two involved parts during the reassembly.	The last part of the criteria gave points to the number of subsystems that were involved in the step being evaluated by the criteria.

Table-A: The above rubric is for the evaluation of the difficulty of each step completed during the reassembly of the Honda Engine. The larger the amount of points that a step scores based on the criteria the more complex the step was. It contains the possible points that each step could score and the description of how and why the points were given to each step.

In the following documentation of the dis-assembly and dissection, the aforementioned difficulty rubric was applied to the steps to describe the complexity of each step.

Procedure:

The dissection was performed in the lab, located in Furnas Hall, during the allotted office hours. It was performed by a combined effort of Team 13 and Team 23. The following is an account of the dissection completed by Team 13:

Dissection Steps:

Step I

Air Box Removal: The first step required Team 13 to remove the air box from the motor. First we removed 8 Philips screws and washers, from the air box to detach the two pieces of plastic housing from each other. After the top was apart we were able to remove the air filter and its housing. The bottom of the housing was removed by loosening Philips head band clamps connecting the air box to the carburetors. The air box was now successfully detached from the motor. Tools: Philips Head Screwdriver No. 2. Difficulty: 27 Intended Dissasembly: This part was intended to be disassembled regularly, as it would require basic maintenance needed to change the air filter.

HondaCBR600 Air Box: This is the air box housed on top of the CBR600 F2 motor.

Step II

Carburetor Removal: The next step was removing the carburetor subsystem from the engine assembly. The carburetors were removed from the assembly by removing Philips head band clamps connecting the carburetors to the intake side of the head. After loosened, the carburetors were pulled off of the intake by hand. Tools: Philips Head Screwdriver. Difficulty: 61 Intended Dissasembly: The carburetor is a more complex subsystem of the motorcycle engine, and is intended to be dissembled for maintenance by a professional of someone with mechanical knowledge of carburetors. It was not designed for regular dissasembly.

HondaCBR600 Carburetors: These are the four carburetors mounted to the head, which mix the fuel with the air from the air box.

Step III

Valve Cover Removal: The next step was removing the valve cover from the engine head. The first step was to unbolt the six 10 mm bolts from the valve cover along with the rubber washers. Next the team member in charge of this task pulled off the valve cover by hand. After removal the valve cover gasket was also peeled off the head by hand. Tools: A 3/8 drive, with a 10 mm socket. Difficulty: 12 Intended Dissasembly: The valve cover was only intended to be removed for professional maintenance and was not intended to be frequently disassembled.

HondaCBR600 Valve Cover: This is the valve cover that encloses and seals the top portion of the head.

Step IV

Camshaft Holders Removal: The next step was removing the holders bolted above the camshafts. The camshaft holders contained 20, 10 mm bolts, connecting them to the head. Since there were two camshafts there were 10 bolts per cover. After the bolts were removed the covers were firmly attached to the head because of their connection to the oil channels. In order to remove the holder from the head it required one team member to pull on one side of the holder while another used a flat head screwdriver to separate it from the head. Once broken free from the oil channels the holders could easily be removed by hand. Tools: A 3/8 drive with a 10 mm socket. A flat head screwdriver. Difficulty: 29 Intended Dissasembly: The carburetor is a more complex subsystem of the motorcycle engine, and is intended to be dissembled for maintenance by a professional of someone with mechanical knowledge of carburetors. It was not designed for regular dissasembly.

HondaCBR600 Valve Holders: The two valve holders are pictured, one separated from the head while the other is still attached.

Step V

Timing Chain Removal: The next step was removing the timing chain from the engine assembly. The team needed to remove six 10 mm bolts from the side of the crankcase to detach the timing chain cover. The next step was to loosen and remove the timing chain tensioner via two 8 mm bolts connecting it to the side of the crankcase. After removing the tensioner, the left and right chain guides were removed by one 10 mm and 14 mm mounting bolts respectively. Then the sprocket connecting the chain was removed from the crank shaft. The timing chain now had enough slack to remove from the camshaft sprockets. The timing chain now had to be removed by guiding it out of the top if the head. Tools: A 3/8 drive with a 8 mm, 10 mm and 14mm sockets. Difficulty: 25 Intended Dissasembly: The timing chain was not intended for dissamebly, and was intended to operate correctly for the expected duration of the engines life. The timing chain would only have to be replaced for unexpected failure.

HondaCBR600 Timing Chain Assembly: The two valve holders are pictured, one separated from the head while the other is still attached.

Step VI

Camshaft Removal: The next step was removing the camshafts from the head. Once the camshafts were free from the timing chain and cam holders they were rested in their respective wells within the head. The cams could then be removed by hand from the head with minimal effort. Tools: None. Difficulty: 5 Intended Dissasembly: The cams were intended to be removed for valve-train adjustment, but were not made to require frequent maintenance.

HondaCBR600 Camshafts: The two camshafts after removed from the head of the engine.

Step VII

Head Removal: The next step was removing the head from the rest of the crankcase. The first step was to loosen and remove ten 8mm Hex bolts, located between the two camshafts wells. There were also two 10 mm bolts on the exterior of the the head located on the timing chain side of the case that needed to be removed. Finally the head need to be worked off with a rubber mallet while one member puller on the head. It also was required that one member secure the crankcase so it would not move during the process. After loosened the head could easily be lifted from the remaining part of the case. Finally the head gasket had to be removed from the top of the crankcase, where it mates with the head. Tools: A 3/8 drive with a 10mm socket. A 8mm Allen wrench. A rubber mallet. Difficulty: 37 Intended Dissasembly: This subsystem of the engine was not made for removal or dissasembly. It would only need to be removed in the case of sustaining damage or during a rebuild.

HondaCBR600 Head: This is the image of the head once removed from the engine, showing the underside which would e connected to the combustion chambers.

Step VIII

Alternator Removal: The next step was the alternator from the crankcase. The alternator was connected to the crankcase by nine 8mm bolts, which were loosened first. Once the bolts were removed the alternator cover could be removed by hand. Then most of the alternator was able to be removed with the cover from the crankcase. Further removal was only resisted by the generation of magnetic force created by the alternator. Tools: A 3/8 drive with a 8mm socket. Difficulty: 17 Intended Dissasembly: This subsystem of the engine was not made for removal or dissasembly. It would only need to be removed in the case of sustaining damage or during a rebuild.

HondaCBR600 Alternator: The alternator after being unbolted from the side of the crankcase..

Step IX

Clutch Removal: The next step was removing the clutch from the transmission casing. Initially there were ten 10mm bolts holding the clutch cover to the transmission that need to be loosened. Next the four clutch springs and the clutch lifter plate were removed from the housing by four 10mm bolts. After that the clutch center nut had to be removed by 27mm socket while a member of the team secured the output shaft with a wrench. Once these were removed the clutch assembly including the 12 plates were able to be removed. After removal the clutch basket was now fully separated from the transmission case. Tools: A 3/8 and 1/2 inch drive with a 10mm and 27mm socket respectively. Difficulty: 41 Intended Dissasembly: This subsystem of the engine was not made for removal. It would only need to be removed in the case of sustaining damage or during a rebuild. The only component that would be regularly serviced would be the clutch friction plates and clutch springs.

HondaCBR600 Clutch: This is a picture of the clutch cover which contains the clutch basket assembly.

Step X

Starter System Removal: The next step was removing the starter system from the crankcase. There was one 10mm bolt that needed to be loosened initially. Once loosened there were two 10mm and two 8mmm bolts that needed to be removed, securing the starter system to the crankcase. After removal the starter system was completely detached from the crankcase. Tools: A 1/4 drive with 8mm and 10mm sockets. Difficulty: 12 Intended Dissasembly: It would only need to be removed in the case of sustaining damage or need of replacement. It is secured to the outside of the crankcase making it an easy subsystem to replace.

HondaCBR600 Starter System: This is a image of the starter system secured to the outside of the crankcase.

Step XI

Remaining External Systems Removal: The next step was removing the remaining external systems including the water pump and the thermostat. Thermostat: It required the removal of three 8mm bolts from the crankcase. Once removed the thermostat could be pulled out of the crankcase very easily. Water Pump: The water pump had two 10mm bolts securing it to the crankcase, this was also easily removed once the bolts were freed. Tools: A 3/8 drive with 8mm and 10mm sockets. Difficulty: 15 Intended Dissasembly: It would only need to be removed in the case of sustaining damage or need of replacement. It is secured to the outside of the crankcase making it an easy subsystem to replace.

HondaCBR600 Thermostat: The image depicts the thermostat bolted to the side of the crankcase.

Step XII

Upper Crankcase Removal: The next step was removing the upper crankcase from the rest of the engine block. There were seven 10mm securing the top of the crankcase to the rest of the block. An additional 14 bolts were located around the sides of the crankcase oriented upwards. They consisted of two 12mm, one 14mm, six 10mm, four 8mm and one 4mm bolt(s). Once loosened it took two team members to pull on the top of the crankcase while another secured the bottom. During the removal friction between the cylinder walls and the pistons made it necessary for multiple group members to apply force. Tools: A 3/8 drive with 8, 10, 12, and 14mm sockets. A 4mm Allen Key. Difficulty: 54 Intended Dissasembly: This subsystem of the engine was not made for removal or dissasembly. It would only need to be removed in the case of sustaining damage or during a rebuild.

HondaCBR600 Upper Crankcase: This is an image of the crankcase housing the four pistons while still connected to the block.

Step XIII

Piston and Rod Removal: The next step was removing pistons and connecting rods from the block. The first step in removing the pistons and connecting rods from the block was locating and unscrewing the eight 10 mm connecting rod cap nuts. This then allowed us to remove the connecting rod caps and the bearing insert. The pistons then slid out of the top half of the combustion chambers. For a couple of the pistons, a rubber mallet was needed to knock the pistons loose from their combustion chambers. Tools: A 3/8 drive with 10mm socket. Rubber mallet Difficulty: 39 Intended Dissasembly: This subsystem of the engine was not made for removal or dissasembly. It would only need to be removed in the case of sustaining damage or during a rebuild.

HondaCBR600 Pistons and Connecting Rods: This is an image of the pistons and their connecting rods.

Step XIV

Oil Pan Removal: The next step in the dissection of the engine was the removal of the oil pan. The removal of the oil pan required the loosening and unscrewing of twelve 10 mm bolts. Some of these bolts had to be removed by an open ended crescent 10 mm crescent wrench. Next, the engine was flipped upside down while one team member removed the oil pan while another secured the base. The gasket was then removed by hand and the drain plug was removed by a 1/2 inch drive with an 18 mm socket. Tools: A 3/8 drive with 10mm socket. A 1/2 drive with 18 mm socket. An open ended 10 mm crescent wrench. Difficulty: 19 Intended Dissasembly: This subsystem of the engine was not made for removal, however the drain plug is frequently removed in order to drain the oil for an oil change.

Honda CBR600 Oil Pan: This is a picture of the engines oil pan.

Note: These steps only describe the dissection process of the separate subsystems. An analysis of the individual components can be found in Gate 3.

Tools:

Table B is a complete list of the tools used by Group 13 that were required for the dissection in Gate 2:

Tools:

Tool Name	Sizes	Procedure	Frequency of Use
Philips Screwdriver	No. 2 Philips Head	Place head into screw cap, turn counter-clockwise for loosening and clockwise for tightening.	Used in 2/14 steps.
Flat Head Screwdriver	Flat Head 3/8 inch wide blade.	Place head into screw cap, turn counter-clockwise for loosening and clockwise for tightening.	Used in 1/14 steps.
Open Ended Crescent Wrench	10mm wrench.	Place the wrench head around desired bolt/nut,use mechanical force to turn counter-clockwise for loosening and clockwise for tightening.	Used in 1/14 steps.
Rubber Mallet	Three halves pound Mallet.	Use mallet to apply desired force to specific area without sustaining damage to the base material.	Used in 2/14 steps.
Ratchet	1/4, 3/8 and 1/2 inch drives.	A ratchet is to be connected to a socket for applying torque to a bolts.	Used in 11/14 steps.
Sockets	8, 10, 12, 14, 18, 27mm sockets.	Fitted to a drive, and secured around a bolt/nut to apply torque need to loosen or tighten. Use mechanical force to turn counter-clockwise for loosening and clockwise for tightening.	Used in 11/14 steps.
Allen Keys	4 and 8mm key.	Allen key mates with female head of bolt, use mechanical force to turn counter-clockwise for loosening and clockwise for tightening.	Used in 2/14 steps.

Table-B: List describes types and sizes of tools used during dissections. Procedures and frequency of use are also addressed.

Subsystem Breakdown:

Subsystem Connections:

The following diagram, Diagram-A, shows the separate subsystems from the dissection and how they are connected. It shows what systems are connected and what is transferred between them. Including the flow of energy and materials between the different subsystems.

Diagram-A: This diagram shows the connection of the subsystems and the transfers between them.

Subsystem Design Factors:

Their are four factors that are considered during the design of a product and the connections of its subsystems. The first two factors in the list has to do with global and environmental concerns. During the early 90s, global warming was less of an issue than it is in the present day. Therefore the design of the engine was more performance focused and less concerned with emissions, as they were not as regulated back then either. The carburetors were tuned with performance in mind and not fuel efficiency. Another factor in the design process is concerned with societal needs, at the time people were more concerned with performance. The engine and it subsystems were designed together for optimal performance and power output. The engine and crankcase were designed to withstand greater amounts of power and the head to handle higher rpms in this revolutionary sports bike. Since society was most concerned with these issues it was the main focus of engine and its subsystem designs. In the early 90s people had more of a dispensable income and the rise in motorcycle sales meant less was held back in the design, and the best parts and performance was the goal of the CBR600 engine. So there were no compromises made in the performance of the engine, it was a priority over cost and efficiency.

Subsystem Arrangement:

The design of the subsystems and the job that they provide to the overall performance of the engine requires a specific arrangement to allow the engine to perform correctly. For example, the air intake is located directly above the carburetors in order to insure that air is placed into the carburetors where it is then mixed with air and fuel. The carburetors are located right above the head because gravity is used in the process of delivering air and fuel to the combustion chambers. If this were not the arrangement of these subsystems, functionality would be impaired. In the case of the Honda CBR600 engine, there are no restrictions in which subsystems cannot be adjacent in relation to functionality, but certain subsystems do have to be adjacent in order for the engine to run properly.

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References:

[1]. Scott, Ed. (2002). Honda CBR600 F2 and F3: 1991-1998. Kansas: Clymer.

[2]. Motorcycle Dealers. (2010, September 27). High Beam Business. Retrieved from http://business.highbeam.com/industry-reports/retail /motorcycle-dealers