User:MAE 277 2011 Group10
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.
-General CAD knowledge -Experience with tools -Engineering Intern Experience
-Lack of engine knowledge -Procrastinator
-AutoCad experience -Engine Experience -Organization
-Time Management -Planning
-Solid modeling experience -Automotive background -Engine assembly experience
-Organization -Time management
-Attention to detail -Diagrams, graphs, formatting
-Lack of engine experience -Organization
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.
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. It is a four stroke, gasoline powered combustion engine utilizing liquid cooling. 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 and producing power that is translated to the rear wheel, moving 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. Firstly, it might be best to start with the exiting energy of the system. Energy is 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. The combustion reaction results from the ignition of an air/fuel mixture converting chemical energy in the air and gasoline and the electrical energy of the spark plug to mechanical energy as a rapidly expanding gas. This initial conversion of chemical and electrical energy to mechanical energy is lead by a series of mechanical energy interactions in the form of mechanical work through the pistons to the connecting rods to the crankshaft and eventually to the wheel. 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.
A 599cc 4-cylinder, using common knowledge alone, has a couple main components with many other minor components and hundreds of smaller parts that they are composed of. Without dissection, it is still obvious that there is an engine block, with pistons and connecting rods. There is a crankshaft housed in between the block and oil pan. Mounted onto the top of the block is the head where a series of intake and exhaust valves and two camshafts reside. Entering the head are four carburetors fed by an intake manifold and air box. There is an ignition system with four spark plugs and associated wiring. Given the usual and proven convention of engines used in transportation devices in the last 75 years or so, this knowledge is obvious without too much inspection. However, not all engines are exactly the same and motorcycle engines are again different than the more common automobile engine. The components are largely mechanical, with the exception of the ignition system, which is electrically operated. As a result, most parts are moving and because it is a motorcycle engine they are moving fast, (a typical motorcycle has a rev-limiter set above 10,000 rotations per minute). To ensure proper engine balance and to prevent malfunction, each part must be machined precisely with low tolerances. Due to this aspect, the engine may be considered complex. The careful interaction of the individual components with each other is what enables the engine to function.
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 and distinct texture. The block will have been made with a metal stronger than aluminum: perhaps 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 user does not directly interact with the engine, as there are mechanisms employed to translate engine activity to intuitive and easy-to-use controls. The 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. 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 simply 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. The overall improvement of the CBR600 over the previous model made it a consumer surprise and a proven performer. With lighter, stronger suspension components, a more powerful engine and better brakes, 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 transportation 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. Another market comparison is shown below where the used prices of a 1994 model of each of the four motorcycles are compared.