Although it’s not a Rotary, this is still neat.
Mazda has now received a patent in the United States for a two-stroke supercharged motor design. This is a fascinating development because you won’t find a two-stroke combustion engine in any modern car. This type of mill is more common in a chainsaw or leafblower these days.
The engine’s two stroke combustion cycle isn’t enough to be fascinating. There are many other features that make it even more fascinating. The powerplant can run at low loads using compression self-ignition, just like a diesel engine. It can then switch to spark ignition combustion for higher loads. Mazda also mentioned variable valve timing in its patent. This allows for high compression ratios while maintaining diesel-like self ignition. To prevent knocking, the timing would change when spark ignition is used to lower the compression ratio.
All of this may sound familiar? It’s , because Mazda’s SkyactivX engine can also switch between compression self-ignition and using a sparkplug depending on the circumstances. The Mazda3 is sold in certain markets by the automaker with this powerplant. Although the patent states that this supercharged two-stroke engine improves fuel economy, it doesn’t specify what layout it compares. Two-stroke mills are known for producing high exhaust emissions. The documentation does not indicate whether this design has any benefits.
This filing does not reveal anything about Mazda’s plans for the engine. If this engine has significantly lower emissions and fuel consumption than a two-stroke, it’s difficult to envision an automotive application. Two-stroke engines are still quite common on dirtbikes. Mazda may license the design to a motorcycle manufacturer. Engineers can always come up with new ideas and patent them. The company has no plans to produce the invention. The company wants to protect intellectual property.