RE: diesel rc airplane motors
PAW .40 R/C ... if you want a "proper" traditional diesel. Will last a lifetime if cared for.
Or, you may care to try a Davis Deisel conversion of a suitable Glow .40. There are plenty of options.
If you can find one, the Irvine .40 Diesel is a superb choice, however they are no longer made, and all old stock seems to have been snapped up.