its so strange you wrote this thread. I was just thinking about this as I was reading howstuffworks.com today (maybe you were reading it too). i havent seen a rotary engine that was air cooled in fact the only ones I have seen were in Rx7 & 8s but a rotary engine would be so sweet because they are so much lighter and can rev to the moon. i heard that military uses it in some of their motorcycles because they have less moving parts and could be serviced easier out in the field but Im not sure how true that is
What could you get a rotary engine from that would be about the right size?
