I bought a China made engine, SC 46, and I do know they are supposedly to be not as good as a TT or OS and of course no where near a ROSSI. I am keen to know what level of performance and engine should have. Running it with a Bolly 10.5 x 7 I am getting about 12.8K RPM. Is that considered good for the prop size? Anyone knows of any document that can tell me what performance is deemed good or great? Thanks!