The proposed changes to the 250 class - with the 250 cc two-stroke twins likely to be replaced with rev-limited, spec ECU 625cc four-stroke inline fours - is having an unexpected effect on the MotoGP class. With KTM and Aprilia currently mainstay of the 250 class, the Japanese manufacturers having withdrawn factory support some time ago, the two European factories are extremely displeased with the new proposed measures. But unless they can persuade all of the manufacturers gathered in the MSMA to vote against the proposals, the two strokes are doomed.
Aprilia now seems to have decided that, with no experience of building engines in the proposed new format, it would be better to focus its attention elsewhere. The Noale factory has already announced plans to enter the World Superbike series in 2009 with a new 1000cc V4, and now, according to MCN, Aprilia are working on a new engine for entry in the MotoGP class. The engine will also be in a V4 layout, and is expected to start dyno testing later in the year.
One interesting detail is that Aprilia will be developing the engine entirely in-house, after their experience with the fantastic sounding, but difficult to ride RS3 Cube bike in the first years of MotoGP. That engine was built by Cosworth, the highly successful car engine builders. But both the Cosworth Cube and the Ilmor project demonstrated that building a motorcycle engine is a completely different kettle of fish to making engines for racing cars. Whether Aprilia can muster the resources and engineering skills to build a MotoGP winning bike is yet to be seen, but small Italian factories building V4s have been remarkably successful in recent years.