interesting split cycle rotary
 

i dont really care about the split cycle part of this designe but i do like the way the motor achieves compresion. check it out.

http://www.youtube.com/watch?v=RieI59-iJzg

Hmm, kind of like a roots blower mating with an odometer gear.

some major problems with that design... notice the overlap on Intake and Exhaust?