Expanding on an earlier Kawasaki patent suggests Mazda may return to motorcycle manufacture.
Unless you're a hardcore Mazda fan, you probably never knew that the company was founded as a cork manufacturer in 1920. If that's not odd enough, its first entry into the automobile industry was not a car. In fact, Mazda began developing its first vehicle in 1929, and it was a motorcycle. The result was a race-winning bike, and its first four-wheeled vehicles only arrived in the 1950s, with its first passenger car launching in 1960. Since then, we've been graced by legends like the MX-5 Miata and the innovative RX-7, but now it seems that Mazda is returning to its roots.
CarBuzz has discovered a new patent filed with the United States Patent and Trademark Office (USPTO) that pertains to a supercharged two-stroke engine. This appears to borrow elements of Skyactiv-X engine technology in that it combines the concept of compression-ignition (combustion without spark) with the principles outlined in an earlier supercharged two-stroke engine patent from Kawasaki. This sparkless-combustion cycle, says Mazda, would occur at low loads when the supercharger would fill the void in intake compression that occurs as a result of having both the intake and exhaust valves open at the same time. This makes direct fuel injection critical so that unburned fuel can't escape into the exhaust.
Under high loads, a spark-free combustion process is typically unrefined and makes a lot of noise and vibration. To avoid this, Mazda's idea sees high-load engine operation occur with the aid of spark, thus maximizing efficiency (for both fuel consumption and thermal management) and improving refinement. When this high load occurs, it seems that the valve timing would be adjusted to allow for regular operation. Ultimately, Kawasaki's design patent showed a four-stroke engine design with a two-stroke cycle and a supercharger. But while Kawasaki's engine added electric assistance to improve efficiency, it appears that Mazda wants to use additional spark to fully exploit the energy of the fuel in the combustion chamber.
Since the automaker already has a range extender solution in the MX-30, we think this must be something that is either not intended for production or will see itself used in something with fewer than four wheels. We'll just have to wait and see.
Keyword: Mazda Develops Highly Efficient Supercharged Two-Stroke Engine