Group 10 2011 Gate 1: Project Planning
The work proposal will give an overview of how Group 10 plans to reverse engineer the motorcycle engine from a Honda CBR600F2 (1991-94). Group 10 will be using current skills, and developing engineering skills to our best ability to dissect, assemble and asses the Honda CBR600F2 engine given to us. Group 10 will use tools in the lab that will be instrumental in the dissection and assembly phases. Since the engine will be shared, communication with the other group working on the engine will be crucial. The proposal will give a close estimate of when each gate will be started as well as when each gate should be completed. Since another group will also be working on the same engine, our days that we will be able to work in the lab may be somewhat different than originally proposed. Also included in the proposal is a brief, honest, summary of capabilities and shortcomings each member that our group possesses. The only initial challenge that our group has identified is that of finding all of the correct tools since there are many different components to be removed.
Dissection and Assembly
Our plan for dissection and assembly includes spending time in the lab as a group, but more importantly having a firm understanding of the engine outside of the lab. We will need strong background knowledge of the Honda motorcycle engine in terms of functions of each part in the engine, where each part is/goes, and why the part is included in the engine. Having sufficient background knowledge of the engine will be necessary in order for our group to be successful in dissection and assembly processes. Group 10 plans on dissecting the motor by breaking down the major sub-systems and analyzing each of the smaller members that make up each of the sub-systems. A log is to be kept in detail for the dissection process, enabling the re-assembly process in the future. This log will have to be used by both groups dissecting the engine so no detail is missed by either group.
|Floor Jack||To support and maneuver engine.|
|Torque Wrenches||To put bolts back in their position with the correct tightness.|
|Metric Sockets||To remove bolts holding parts together.|
|Allen Wrenches||To remove fasteners.|
|Screw Drivers||To remove Flathead and Philips screws and fasteners.|
|Valve-Spring Compressor||To remove valve springs.|
|Snap-Ring Pliers||To remove snap ring fasteners.|
|Rubber Mallet||To loosen and re-assemble pressed components without damage.|
|Andhor, J.|| -General CAD knowledge
-Experience with tools -Engineering Intern Experience
| -Lack of engine knowledge
|Sjoberg, N.|| -AutoCad experience
-Engine Experience -Organization
| -Time Management
|Fonseca, F.|| -Solid modeling experience
-Automotive background -Engine assembly experience
|Siegel, B.|| -Charts, Diagrams, Figures
-Formatting, Attention to Detail
| -Group Work
Group 10 will meet every Monday after class at 5:00 pm to discuss our plan of action for the week. Meetings will take place in the 3rd floor of the Capen library and will last approximately half an hour depending on how much needs to be accomplished. All group members are expected to attend barring acceptable excuses or unless otherwise stated. The meetings will consist of reviewing each previously graded gate in order assess possible improvement and changes. These changes will then also be implemented in future gates. Once that is completed, we will then discuss what the next gate entails and how work will be delegated. A plan of action for physical work on the engine will be created along with a schedule of who can attend each available office hour. The purpose of these meetings is to promote a level of organization and preparedness in order to have a clear objective of the task at hand.
Will initiate meetings based on the availabilities of group members, approve what will be posted as final on the Wiki, fairly distribute any further duties that may come up over the course of the project, and be responsible for assuring that all group members remain informed on the status of the project.
Will be responsible for conveying information from within the group to outside sources, and vice-versa. This includes upkeep of the wiki page, relaying any necessary information between teachers and the group members, and taking care of necessary communication between the other group sharing the engine.
Will be responsible for ensuring that the group members are aware of the specifics of the engine being dissected. He will research and be aware of the purpose of each part and how it contributes to the operation of the engine.
Will be responsible for the clear depiction of the process and parts involved in this project, creating virtual models of the engine, detailing the operation of the engine, and visually representing the proposed improvements on the product. This role may share similar functions with the Communication Liaison, as the representations done by the Delineator will be a large part of what is posted on the wiki page.
Point of Contact
Conflicts will be resolved in the group meetings by Benjamin, the project manager. Input will also be required from all parties involved to assess the problem at hand and to find an adequate solution. Scheduling conflicts will be assessed based on the priority level of the excuse compared to the level of work missed. Full transparency in all group member's schedules will help address conflicts in work load.
Honda began development of the CBR600F2 in early 1989, and it was officially launched to the public in 1991 to replace the CBR600F1 . The purpose of the engine was to re-establish Honda’s position in the mid-level category of sport bikes and to provide a successful replacement to the F1. This saw the first 600 engine to boast 100 bhp from the factory along with 47 lb-ft of torque. At its time of production, emphasis was not heavily put on environmental friendliness, but more so on performance. Even so, the engine still managed an impressive 46 miles per gallon which continues to be comparable to many new engines today. The F2 was marketed globally, but had the greatest level of success in Japan, Europe, and the US. An extreme attention to detail and an obsessive drive to maximize efficiency made the F2 the fastest middleweight money could buy and it was marketed accordingly. It was catered to the enthusiast of the time who wanted the utmost performance at a reasonable price .
The new 600 engine was designed to power the CBR600F2 motorbike. Through a four stroke spark ignition combustion cycle the engine converts gasoline to rotational work that eventually turns the rear wheel. This propels the bike forward. The engine was designed for recreational use by the public but also with professional racing in mind. The F2 was used as a mode of transportation, source of entertainment, and a performance engine that was used to compete in international racing series.
The inline 4-cylinder engine used in the PC25 is an example of an internal combustion engine which follows the same profile for energy use/exchanges. The cycle is completed in four stages, the first of which is the intake stroke, where the crankshaft pulls the piston from the top of the cylinder to the bottom creating a limited vacuum. This causes air and fuel to be pulled into the cylinder from the carburetor. The second stage is compression, where the piston is forced up to the top of the cylinder again, compressing the air and fuel mixture. The third stage is the power stroke, which is where the air and fuel mixture is ignited by the spark when the piston reaches the top of the cylinder after compression. The mixture expands quickly and pushes the piston back down to the bottom of the cylinder, turning the crankshaft . Energy is then expelled from the system in the form of mechanical work, propelling the rear wheel, and as thermal energy in the form of the hot exhaust gases leaving the engine. Chemical and electrical energy provide the fuel for this reaction.
Ideally, the total quantity of energy entering the system would be the same as the energy leaving the system. In this case, the sum of the internal energy of the air/fuel mixture would equal the work done on the wheels and the thermal energy released by the exhaust. However, in reality, energy efficiency is often not higher than 18-20% in naturally-aspirated engines. Losses are largely due to heat and friction. The PC25 engine was commended for its improvement in efficiency over the previous model, as Honda made a relentless effort to reduce the internal friction, resulting in a 17% gain in power with the same cylinder displacement .
The engine is composed of several hundred parts. The parts come together to form fewer but larger components, and the components come together to form about a dozen systems and subsystems. The parts almost all operate mechanically, with the exception of the ignition system which operates electrically. Mechanical systems demand fewer materials than electrical ones, and are less prone to failure. The combustion reaction is the most complex process in the engine as the many components must work in unison to deliver a perfect air/fuel mixture. The second most complex system is the gearbox which houses over fifteen gears and spindles that are constantly being reconfigured while transferring energy. Most other interactions are simple mechanical energy transfers that do not change the form of energy. More complex mechanical reactions may convert translational to rotational energy like the transfer of boundary work in the cylinders to the pistons, through the connecting rods and into the rotating crankshaft.
Most moving parts in the engine are made of some type of metal, for longevity and strength concerns. With the exception of seals, or other minor parts, the engine block and head are mostly metal, with the head most likely made of cast aluminum—as indicated by its pale color, rough finish, and visible parting lines. The block is made of cast iron to cope with the stress of the expanding gases and moving cylinders. The airbox is made of plastic to save weight, considering it is not a component exposed to deformative heat and because the only thing moving through it will be air. Many of the other caps and covers that will not be exposed to either heat or mechanical stress are also plastic or rubber, like the seals between the intake ports and the carburetors. The exposed gears are most likely made of a purposefully hardened metal to maintain the crucial distance between teeth of other gears in contact. The hardware is all made of stainless steel. Inside the engine, the majority of the parts and components are probably made of metal alloys to withstand the high combustion temperatures, and the 10,000 revolutions per minute engine speed.
Spring-loaded butterfly valves on the carburetors are linked to the throttle control on the handlebars, providing total control of the engine to the rider. The throttle control is sensitive to human logic; the faster you pull on the throttle, the faster the bike will accelerate. The concept of a hand-controlled throttle and foot-operated transmission is one that is used on most bikes, and thus is a configuration that motorcycle owners are all familiar with. Braking and gear changes are also controlled from the handlebars and are identical to most other motorcycles. Regular maintenance is required on this product to ensure longevity and full functionality. These include oil changes and oil filter replacements after every 8,000 miles recorded, radiator fluid changes every two years, and air filter changes every 12,000 miles. General maintenance also calls for the cleaning and inspection of many components like the carburetor choke, idle speed and synchronization, valve clearance and the cooling system. These can all be done given the proper tools and a little experience, although most can be done very easily without any .
The CBR600F2 easily reached the top of the middleweight sports bike category, with several magazines even claiming it the best motorcycle money can buy. With lighter, stronger suspension components, a more powerful engine and better brakes compared to its predecessor, the riding experience was unparalleled to any of its competitors. Taking cues from the racing industry, the bike was able to satisfy the performance demands of biking enthusiasts while still providing transportation at low costs. However, sacrifices are still made in the comfort department due to the aggressive riding position. Drivability is also primarily limited to fair-weather days, and almost entirely rule-out the winter season. A side-by-side (performance) comparison was found of a Honda CBR600F2 versus a Kawasaki ZZR600 where the conclusion was made that the Honda was a little bit slower in a straight line but was much more composed in the corners, being able to handle faster corners more accurately than the competition . A market comparison of performance was illustrated in a graph below where a reliable measure of a motorcycle’s acceleration, the power-to-weight ratio, was calculated for several market competitors to the CBR600F2. This is not a perfect depiction of performance, as handling cannot be measured in a power-to-weight test, but even so, it is clear that in this department it is above most competitors. Another market comparison is shown below where the used prices of a 1994 model of each of the four motorcycles are compared.
Honda CBR600 (1991-1994) Service Manual