Irvine 15R racing glow motor. This engine has been used but I doubt if it has done a lot of work there are only slight washer marks on the case and the spinner is uncut. The fits are excellent with very good compression and smooth bearings. I dont think the the engine is pipe timed so it was probably intended for free flight power or a class of control line racing. These are very powerful engines and although easy to start they require some experience to operate them effectively. The engine is very collectable.