ORIGINAL: I-Love-Jets
Hello MJD,
you should adjust your estimation downwards to get true 30000 rpms on the ground. A 6.5x6.5 is the ideal prop size for a .28 converted car engine for speed application. That prop size makes such an engine run at its optimum level, i.e. the torque/power peak.
I can believe that. A prop that size must look unusual on front of a .30 size engine.. but I bet it sounds cool.