Kawasaki recently filed patents for an in line four cylinder motorcycle engine with an uneven firing order. While similar to the design from Yamaha in the latest R1, the Kawasaki engine design steps things up a bit by adding some electronics to aid the uneven firing order.
The Kawasaki design would traditionally have had problems, in that the radical nature of the firing order would have made the engine incapable of running at low RPM, due to a lack of momentum in the crank on the long 540° revolution. The second problem would have been the requirement for a very heavy and almost impractical crankshaft, which would have made the engine slow to rev, and would have limited high end RPM.
Kawasaki have solved these problems by using clever electronics. An electric motor operates only on every second revolution, during the compression stroke, and only on cylinders one and four. This tiny electric motor operates only long enough for the motor to gain momentum, and then switches off again. Engine sensors are used to monitor crank angle, degree of throttle opening, vehicle speed and gear position. The new electric motor will also be used as a generator to charge the battery when it's not boosting the crank, and that means it can do the job of the traditional alternator too.
What does this all mean? Well to you and me, probably nothing other than a bike that sounds like the Yamaha M1, but if you are a really good rider, you will now be getting more traction and therefore better feedback from the rear tyre under acceleration, meaning faster corner exits, and ultimately better drive out of corners which means better speed down straits and hopefully an advantage for the green team (and don't they need one right now?)
The radical 540° gap in the firing order is double the gap that the new R1 uses, and means that the ZX-10R motor turns a full one and a half revolutions without any cylinders firing. The gap in the R1 firing order is only 270° which in itself was considered rather long.
However the most significant benefits from the Kawasaki design are that the crankshaft retains the natural balance as found in a traditional (screamer) in line four. This in effect reduces production costs, improves reliability, and also enables the normal high rev limit found in screamer engines, which means that the peak power output will not be adversely affected.
It seems like next year the major brands will all be making V4's or 'Big Bangs' if they want to stay competitive. Aprilia have already gone the V4 route, so we still need to find out what Suzuki & Honda have planned. Honda could easily build a V4, and Suzuki have the GSVR in MOTOGP which is a V4, so they know how to do it too. It looks like 2010 is going to be another one of those years with amazing technology coming to the consumers because of racing...
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