Cappio777

I was just doing some calculating and according to my #'s in order to even get to .8 the speed of sound a

13" prop would need to turn 16,000rpm
14" -15,000
15"-14,000
16"-13,000
17"-12,000

Do I have these numbers correct? If so, a sport motor would not achieve these numbers at static with a 6 -8 pitch prop. I know I was the one who started with the extremes. I do want to learn about this stuff.