With MotoGP as a pure prototype class, manufacturers are free to change the design of their machines at will — no homologation requirements, for instance. Honda has more prototype, four-stroke racing experience than any other motorcycle manufacturer currently competing in MotoGP. For instance, Honda has built Formula One racing engines for many years and has even won the Formula One race car championship.
Honda is already dominating MotoGP without employing its best four-stroke technology. If, and when, Honda needs more engine performance in MotoGP, it can summon this technology, including, but not limited to pneumatic valves.
As the other manufacturers are playing catch-up, Honda is likely planning its next move to a higher performance plain. With a healthy Valentino Rossi in the saddle, Honda just might be untouchable for the forseeable future.
Only relatively small Aprilia has pulled out most of the technological stops in developing its MotoGP machine — a three-cylinder (subject to a lower minimum weight than the fours and fives) featuring pneumatic valves, a very high rev ceiling, and a huge power-to-weight ratio (check the speed trap numbers on some of the longer straights this year — Aprilia typically achieves the highest speeds, challenged only by Honda). Aprilia is at a relatively early stage of development with its bike, however, with a single rider, and it obviously lacks the resources of Honda.
The bottom line is that Honda’s performance level in MotoGP will remain a moving target (moving ever higher) and it will be interesting to see which manufacturers can challenge Honda in the future.