With Yamaha’s V4 MotoGP machine about to make its debut at the Misano round of WorldSBK in a week’s time, it is worth examining why Yamaha have switched from a transverse inline four to a V4 engine layout. Although photos of the bike were published earlier by Motorsport Magazine, Czech photographer Jaromir Havranek kindly made the photos he took of the Yamaha V4 at the private test at Brno in July available to MotoMatters.com so we can take a closer look at the bike.
Firstly, why have Yamaha decided to ditch the inline four? Several reasons. Weight is one: a much shorter crank and narrower crankcase means the engine can be made to weigh less. Engine width is another: two banks of cylinders can made much narrower than one bank of four cylinders. That leaves a lot more room for aerodynamics to be used, which is even more important for 2027, when the maximum fairing width is being reduced. And it is easier to get more power out of a V4 than an inline four, as the stresses on the crankshaft are lower, and the cylinders are easier to cool.
