Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Very nice little engines. What is the maximum RPM full throttle?

Well, that is of course entirely dependent on the pressure/volume/load it is being fed/worked, so there is no defining upper limit per se. At some point it would no doubt either fly apart or lock up, but I for one am not about to go in search of those limits. I can assure you that in my experience, the RPM potential on these engines is pretty high, based only on what my ear tells me when running one free of load on moderate pressures in the 20-25 psi range.