Honda has filed yet more patents for supercharged motorcycles engines, proving the Honda engineers see forced-induction technology as a viable means to beating emissions restrictions without compromising performance. Recent patents showing twin-cylinder and four-cylinder designs have been filed over the past few months, and the latest one is yet another iteration of the idea.
The latest patent is specifically about the use of an electric pump in a water-cooled intercooler set-up in supercharged motorcycles – something that could be applied to a wide range of different engines in the future. The engine in the drawings appears to be a parallel twin or even a single cylinder, but it could also simply be a test engine to check out the new supercharging technology rather than one specifically destined for a future production motorcycle.
Certainly the exposed supercharger drive belts on the engine's left hand side aren't suited to a showroom model – as well as making for a very wide engine, they'd risk catching on clothing and lack all the elegance of Kawasaki's far more integrated supercharger drive system. However, on a prototype engine designed to test other elements of the supercharging system, they'd work just fine, and that's probably what this is. Unlike Kawasaki, Honda has opted to use an intercooler. It is small and mounted where the supercharger attaches to the pressured plenum chamber. It also uses a separate liquid-cooling system to the engine, with the electric liquid coolant pump taking the coolant to a radiator at the front.
As well as being supercharged, the Honda engine uses direct fuel injection – something that is becoming common in cars but has yet to appear on a production motorcycle. That could be an indication that it's a low-revving engine, since direct-injected fuel has less time to atomize. And while it's harder to implement on high-revving motorcycle engines, it's not impossible.