ORIGINAL: AMB
Steve I do not fly c/l at this point 9x4 or 8x5 may depend on the plane what gives more thrust the 8x5 or 9x4 ??? martin
What RPMs do you turn on the above they certainly will swing an 8x6 martin
Thrust is determined by diameter, airspeed by pitch, so a 9x4 will give more thrust than an 8x5.
And I agree with Steve about the 8x6 as a great start point for all 2.5cc diesels.