As far as the wankel motor goes....I had one of these years ago...It's a 1968 Polaris Wankel Colt snowmobile. I can guarentee you that GM had absolutely nothing to do with the design of this motor

oh yeah. He was 50 some years old when the first rotary engine ran. He worked on the development of some other stuff, like valves and even soem sort of turbin engine but they never panned out.