Wouldn’t it be nice if you could beg, borrow or steal a correct test prop for the motor? Then you could run it WOT without going anywhere.
EDIT: Since writing that, I got to remembering how scary it is to stand next to a four or six cylinder motor running at 5000 or 6000 RPM. Downright terrifying, actually. I once had a V4 Fat Fifty toss a rod on me at only around 2000 RPM or so. I also knew a man that had a flywheel explode in his face.
