Hi Bill,
I think the C150 cabin is not large enough to make significant behavior difference for about 1.5" prop length.
I find that very interesting, Fred. When we purchased our previous 100 HP 150, it came with a well whittled prop shortened from 69" to 67". I replaced it with a fully dimensional prop, same 48 pitch, and the result was very noticeable climb and cruise improvement. I would then think that the larger dimensioned prop of the 150/150 would show even greater degradation as it was shortened? Apparently not true.
I wonder if that may be because the 150/150 is nearer the airplane's performance upper limit? With the 100 HP 150, there was quite a bit of room to show improvement. So minor changes showed greater results. The 150/150 is closer to the aircraft's maximum performance. So maybe greater changes are required to see any noticeable results?
I have been in search for a fully dimensional prop. Thinking I would get the same performance enhancement as when replacing the prop on the 100 HP 150. Now? With what you are saying, Fred, that inch and a half more prop isn't really going to give me much, if any, performance gain? In other words, I should just be content with what I already have.
Though, still searching for that set of patroller wings!
Thanks Fred!
Bill
Grants Pass, Oregon