That looks really interesting, but by "prototyping" do you mean in full scale? It would be a bit too much of a pain in the ass to do the forced induction on a smaller scale model I would think.
What is in it internally, do you have a cutaway view? If it is rotary what do you think the tip seals could be made from that would hold up - that we could get hold of or be capable to machine? Especially with forced induction.
I am VERY glad to see an interesting topic to discuss as opposed to the water engine crap. That much stupid was making my brain hurt. This however, looks like fun!