The Dec 2011 issue of Experimenter Magazine tells of a new Diesel "Flat V 8" out of Wisconsin.
The test pilot for this engine is Dick Rutan.
Here is the URL:
http://www.eaa.org/experimenter/issues/1112.html

On the Zoche engine: I believe that Mr Zoche just likes coming to OSH each summer. By displaying his engine, he can write the trip off his taxes. For 10 or 15 years now his website says that certification is just around the corner. I happened to be in the Zoche booth at OSH when Burt Rutan got down on his knees and begged Mr Zoche for two engines for his Boomerang (which was designed to use Zoche Engines). Mr Zoche said he wouldn't let any out until certification. I'm pretty sure that it will be a really chilly day in a normally hot location before the engines will be delivered for aircraft use.