During the early conceptual stages of development, a variety of engine layouts were considered. However, due to the many technical advantages of this configuration, this choice of engine architecture was deemed most appropriate.

• Kawasaki’s all new In-line, 4-cylinder MotoGP engine.

1) Compared with a V-engine, the evenly spaced firing intervals of the In-line Four greatly simplify tuning of  the intake and exhaust systems. Another related benefit is perfect primary balance, obviating the need for a balancer. In other words, it is an inherently well-balanced engine.

2) To achieve the desirable power characteristics with a 4-stroke engine, a rather long exhaust system is needed. However, the unequal front/rear spacing of, for example, a V-engine’s exhaust ports, requires complex exhaust plumbing to achieve the required lengths. Obviously, the In-line Four design eliminates these problems and gives the engineers a great deal of latitude in tuning the exhaust system for the desired power characteristics. 3) Compared to a V-engine, the In-line Four engine’s compact cylinder head makes it much easier to mount in a frame.

* The main reasons for choosing this layout are as follows:

In preparation for Kawasaki’s entry into MotoGP, our prototype GP bike is undergoing thorough race-testing in Japan, where development is proceeding on schedule. Following is an outline of Kawasaki’s development concept of the bike and of the bike’s main features.

The frame and other components are also newly designed, all with the goal of maximum overall performance.

A variety of new technologies are being used with the In-line Four engine to achieve an impressive level of performance.

• Lightweight, Thin-walled Aluminium Castings

Castings are usually thought of as being thick and heavy. However, Kawasaki’s new GP bike will utilise lightweight, thin-walled castings. Improved casting methods along with the best materials are being used to create a strong and rigid frame, while still offering the desired amount of flex. Compared with conventional frames made of welded together pressed components, the new thin-walled aluminium castings require less welding, resulting in a lighter frame.

Fuel injection systems require large amounts of electric power. Obviously, if a large generator is fitted to supply this power, the weight of the bike goes up and valuable space is consumed. To achieve the needed power output with a relatively small sized generator, the MotoGP bike uses a high-speed, clutch-driven generator. This design uses a conventional, compact and lightweight generator but increases its rpm so that it generates the output of a larger unit.

Conventional generators require the use of idler gears or chains to drive them. However, by driving the generator with the existing clutch gear, the extra parts and weight associated with conventional generator drive systems are eliminated. Clutch housing, Generator & Crank gear are all not needed.

This sophisticated fuel injection system combines the advantages of a carburettor with the advantages of fuel injection. The Keihin FCR-i system used by Kawasaki resembles a FCR carburettor. Unlike conventional fuel injection systems, which usually locate an obstructing butterfly valve in the intake tract (see lower left diagram), this system uses a slide like that used on a FCR carburettor.

As a result, when the throttle is fully open there is no obstruction in the intake tract, and flow through the intake tract is greatly improved (see upper left diagram). Fuel injection will make it easier to control fuel consumption when the fuel capacity regulations come into effect in 2004.