Rotarys are great! Very similar to a 2-stroke in sound and power output. Those things can rev to the moon too!
I remember going to the dragstrip 20 years ago, and there were a group of hispanic guys driving these TINY foreign cars. I laughed at them - what the hell are they gonna do with THAT?? Well, after one of them ripped off a 10.23 @120 mph, I wasn't laughing anymore - I instantly gained respect for these things. They all had rotary engines. I was an instant fan!
Interesting designs here .... but, I don't understand why we don't just improve upon what's already out there. Simple and cheap. Take a 2-stroke engine -- look at what Evinrude has done with the E-Tec engine. It rivals 4-strokes in emissions, and it's lighter, faster, AND cheaper. 2-strokes are the way to go IMO. Can't seem to convince any engineers of that fact. Probably because none of them ever work on engines!