Pictured below is a 35 HP gen-set diesel engine next to a 40 HP LiquidPiston diesel engine. Very interesting, eh?
But this time, it features enough compression ratio to run compression ignition (diesel) and has 3 combustion cycles per revolution. It also features atkinson cycle operation as well, so it's much more efficient than a typical diesel. The big question, can this engine feature more favorable idle and low-load factor operation to overcome the fuel efficiency drawbacks of a typical rotary combustion engine? It's always interesting to see these new engine architectures.