Well... I haven't heard it called cavitation when referring to an airplane prop before... but I have noted that you can stall the prop by turning too high an rpm at too low an airspeed. Cavitation normally refers to forming air bubbles with a boat or ship's prop when you "stall" it in the water. The phenomenon are similar in that each will show a loss of effective thrust compared to the rpm. Both also increase the noise produced.


Sometimes... you want to spin the engine up to a high RPM by using a lighter prop load. My recent problems getting an O.S. .46 LA to run properly were finally overcome when I used a 10X4 to unload the engine. The light load allowed it to turn an rpm that finally brought the engine up to correct temperature. Trying to run it lean enough to get above 7k rpm with the 11X5 or 10X6 just wasn't working (it was running cold... and just died if leaned more). NOW the thing is turning a 11X7 at 12,500 rpm, which is appropriate for the LA. (I guess I had to show the engine how fast I wanted it to turn a prop .)

Note... from my experience with the Magnum XL series... I wouldn't expect much better performance with Magnum's .46 than what I got from the O.S. LA. Maybe 13K with a 11X7 when its running correctly. Magnums seem to be good reliable engines... but not the highest power sport engines on the market. Good "bang for the buck" though. (cheaper than the LA... a little more powerful too.)