Nothing really new. The RCV brand of engines have been around for a while. Don't know their availablity now. We did order in a few on special order at the hobby shop I work part time at. The Russian "Aero .35" is one that is quite collectable. Think of a Fox .35 with the cylinder laying down. If I remember the story correctly, there was a USSR control line scale modeler that dominated the worlld champs for years with a twin cargo model that had these engines in the so no cylinder was sticking out of the cowlings, simulating a turbine engine. He even engineered reverse pitch prop function so he could demonstrate that as one of his control options. One year at the SIG contest, Glenn Lee had a double size copy of the Aero .35 that he built was really neat, but I don't know if he ever ran it. It's a nice, novel way to power a model, but like the Wankel, if it was any better, we all would be using them.
Type at you later,
Dan McEntee