Yellow Aircraft P-47. Not a small or light plane. Taurus 3.2 (52) swings a Zinger 4 blade prop at 7,200 rpm to drag it around in Utah. The reason I mentioned the state is becuse not much of Utah has seen sea level since the day of the dinosaurs. Agreed I don't know the specific size, and Zinger is not the best prop around, but it's the one flying that P-47.

7,200 rpm with a 2 blade prop would be pretty reasonable numbers for most 50cc engines.