My brain was clearly not working right when I wrote that, though the mental image of a Mazda RX-7 engine strapped to the front of a beaver is certainly amusing.

In the early days of aviation there were actually rotary engines that were like radials, but where the entire engine rotated: https://en.wikipedia.org/wiki/Rotary_engine

Wonder if anybody ever tried that. Somebody must have, decided the gallons per hour was ridiculously high, and abandoned the idea.

There have been many attempts with the 13B. One I saw it all worked, except the exhaust system. Builder went through everything, built 3 or 4 of them. The last was made out of titanium welded by guys who worked for a defense contractor.

Failed in flight like the rest of them. He ended up with a lycoming.

In a similar way, there are kit planes which use EJ and EA series Subaru engines. These tend to be a bit more fuel efficient than Mazda rotaries though.

They're used in drones

https://www.aieuk.com/wankel-rotary-uav-engines/