This is the [link=http://www.quicktechhobby.com/Car/Compagnucci/moto_automodcomp1.gif]exploded view[/link] of the engine. It seems easy to adapt for airplane use.

I also found [link=http://www.rconline.net/magazin-2001/mac-6/mac-6.shtml]this article [/link] on the .39 engine