Check out http://www.wankel.org/

Listed on http://www.rotaryeng.net/interesting.html

Mark Wrathal's web site for Rotary Engine Best Practices.
Derived from the archives of the ACRE NL.

This Site is an attempt to provide the best practices for the aviation
use of Wankel rotary eninges. The Idea was suggested in Oct 2000 by
Dale Smith. The knowledge present on this site is a synthesis of the
information discussed on  Paul Lamar's ACRE's email newsgroup . The
information presented here is only a summary of the majority opinion.
If you are intending converting a Rotary engine for aviation use, it
is highly recommended that you subscribe to the list, and purchase
the CD archive,  this 13B Overhaul Video, and  the installation manual.


Looks like the CD and video links are broken,,,

-dave