Has anyone ever got a mph reading on a H9 P-51D With a saito 100. I was wondering what kind of prop it would turn. Its either that or a os 91 fx. but i don't think it would pull faster.

I know this isn't an answer for either of the 2 engines you mentioned but, I have a Hangar 9 P-51 with an O.S. 1.20 Surpass III turning an APC 14 X 10 prop and burning helicopter fuel. Radars in the mid 130s.