I picked up 3 of these at a swap meet a couple weeks ago. Mine are the older models. Anyway last night a buddy and I played around with them and got 2 running. We ran out of time to try to run the third one. They sound very nice,Spew lot's of fuel, and drink alot too. They seem to be very touchy when it comes to the needle position but these that I have probably all need to be rebuilt. I dissassembled one completely and they truly are a work of art.
As far as a practical use I don't think I would want one inside a cowl, they are messy and run very hot. I plan to mount one on a lightened dazzler plane i have just to give the guys at the field something to talk about.
try this site to read a great arcticle about this little gem.

http://www.qsl.net/xq2fod/aeromod/wankel/wankel.html

I'd also like to hear from other people about their experience with this engine.

Jerry