Sean:

Thanks for coming in here regarding Steve the DipStick. I've been pondering exactly how to answer since he made the post, perhaps I over simplified the thing. But I've had too many positive comments from people who now understand exactly what p-factor is to think it's really unclear. Even had an instructor come back and say using my explanation made his ground school classes go much easier.

A three blade prop with equivalent engine load as the two blade will have very close to the same p-factor effect when operated at the same rpm.

Bill.