In reading some of the forums, it looks to me that most glow engines are made and timed for a certain RPM. Can the crankshaft be modified or one built to change this to increase rpm for a certain prop size for planes? And if this is possible would it be to retard or advance the timing. The next question would be would I have to change compression, nitro or such to also change the time along with it? This would be a general question for any engine.