Thanks for the replies, guys. The engine looks identical to the one CCRC1 has pictured with the exception that the needle valve is in the side of the carb instead of on the back plate. For some reason, I believe that this is a .45 size engine, but it is massive for a .45. I have a Tower .46 in my collection and I thought that thing was physically big, but this thing is even bigger. I just went out to the shop and got a digital caliper to do a couple measurements on this thing. The crankcase just under the mounting lugs measures 1.435 inches (36.4mm) and across the head measures 1.807 inches (45.9mm). That just seems huge for a .45. Funny you guys mentioned a Senior Kadet as that is exactly the airplane I was thinking about using it in.