Jeff Scott wrote: "That is a 200 cu inch engine Continental Engine (Air Force used these in both APUs and fuel tanker trucks) but likely has an C-90 camshaft in it, so has significantly less cam duration and is tuned for 2400 - 2500 rpm. Seems to me they also have a flange stud that is slightly off line for indexing, so the prop may require having one hole opened up a bit. Hey, but with the intakes on top, you could just tell everyone it's the latest tuned top intake model like the IO-360s and IO-550s found in the Cirrus Aircraft. I've only seen one of these engines in service in an aircraft. That was on a Dragonfly. He called it a top intake C-90, but the plane performed pretty well with it.
FWIW, put an O-200 cam in it if it isn't already, magnaflux the crank so you know what you have, or switch to an O-200 crank, then mount an Ellison throttle body to it and you would have a nice engine. But even if it's only a C-90 configuration, it would perform well in a KR." I would add to that my hangar mate has been flying a VP2 with one of these converted GPU's known as PC-60's they share most of their components with C-90's. The case is significantly different and is set up to be bed mounted. The cylinders not only have the intake on the top but also is drilled for only one spark plug. My hangar mate drilled the cylinders for the extra plug and had the cylinders honed and chromed as they had some pitting. A second mag was installed on the accessory case where the starter normally resides on the GPU. The crankshaft flange was opened up to correct the offset mounting hole and Continental prop bosses inserted to match the normal pattern. He just turned over 1000 hrs with no significant problems. The only real problem is that with the case it has it is a bit heavier than an C-90 and doesn't seem to put out the equivalent horsepower. Otherwise it is good solid engine that has served him well. Rick Human KR-2 N202RH Houston, Tx
