While browsing on the YouTubes, I stumbled across a fascinating little
film clip.  A group in India is working on some small rotary engines
and testing them in light aircraft:

http://www.youtube.com/watch?v=YNU1wBhIVWc&mode=related&search=

Has anyone heard of these folks before?  In the video, they test a
35hp engine on a weigh-shift ultralight, then mention that they're
working on a more powerful one for a larger plane.