To make a comment on one of the above posts regarding lifespan. A properly broken in, fed, tuned and cared for glow engine should last about 400 hours of run time. My experience has shown me exactly that and has been verified by George Aldrich (prior to his passing). I have seen control line engines and many lapped iron engines exceed that. These numbers will hold true assuming the metalurgy of the engine is of a quality nature. I have not had any of the newer engines long enough to verify the numbers in designs that have only been available for a short time. We'll see what happens.