I would go with one of Richard Sohn's one rotor engines.
It has been in the works for many years and Richard is a very
meticulous engineer. It is now ready to fly. It will run at full
power forever as it is extremely robust to say the least. Most
moving parts are 2 rotor sized. The end housings are two piece to
save weight yet still use the excellent wear advantages of porous
cast iron.

No piston engine would come close to the durability of this engine.

Paul Lamar

Is Richard Sohn interested in producing and selling to other rotorheads
the single rotor engine design he has developed?

Kevin Richey

I don't know? Why  Here is Richard's email address.

Richard Sohn <res12@fairpoint.net>

Paul Lamar