The Return of the Two-Stroke Could be Mighty
Two-stroke motorcycles are typically off-road motorcycles these days, and we don’t see many of them. Four-stroke machines have taken over, but not everyone has left two-strokes behind. I keep one in my garage, and there’s something special about the engine design. Kawasaki knows this well, and the company seems to not be letting go of the ring-ding-ding, ring-ding-ding engine type any time soon. The company patented a two-stroke with a supercharger and a cross-plane crank, according to Visordown.
The patent shows an engine that is truly unique. It is a four-cylinder, two-stroke with a cross-plane crank, and a supercharger. That’s not the weird part. The weird part is that Kawasaki’s engineers have it powering a hybrid system and not the rear wheel.
Two-stroke engines went by the wayside, in part, due to emissions. However, they can run efficiently if tuned properly and run at lower RPM. Adding this engine to a hybrid system could allow it to run at a lower RPM, stay clean in terms of emissions, and then provide power to a battery system for a hybrid motorcycle.
There are two innovations that Visordown points to that allow the two-stroke engine to perform cleanly. The first is the supercharger. By pumping more air into the engine, the engine will run a little cleaner and more efficiently. The other thing is that this design uses valves at the top of the cylinder instead of ports. The valves are both opened fresh air is forced into the cylinder by the supercharger and the exhaust is forced out. All of this makes it highly efficient. This is nothing new, but it’s something you just don’t see on a two-stroke engine.
It will take some precise tuning for Kawasaki to get it right, but when it does, the engine could be highly efficient. The addition of the cross-plane crank will help keep the two-stroke running smoothly. The typically buzzy engine type should absolutely purr. This could be a very interesting engine for a Kawasaki machine. At this time, it’s unclear if this will make it to production, but Kawasaki is definitely working on it.