"tffy" wrote in message
oups.com...
This is for a hypothetical ultralight design, so just looking for
suggestions here of where to look at... hopefully a 4-stroke, purchase
price doesn't matter much, certification status doesn't matter either.
Long time before overhaul matters A LOT... so, the longer the better.
Is there anything out there in the 80-hp range? How about a motorcycle
engine conversion - how long can those go before needing to be
overhauled?

Beemer? http://www.microlightsport.co.uk/Cat.../bmwengine.htm I have
spent thousands of hours riding on top of my BMW engine, and often thought that
I wouldn't mind flying behind one. That said, they have never been terribly
popular with homebuilders for some reason.

Vaughn