I can spend a whole flight within an imaginary 50x50 box...That means the airplane is going slow, with the nose up and bad airflow over the engine. Airspeed probably never exceeds 10 MPH...

I use a Pro .46 (Tower muffler) and am really worried about it...It wasn't made for this. It wasn't made for long mid-range runs with little or no airspeed, just what the prop blast gives it. This poor little engine has to keep my overwight Sledge above ground level...

I never use anything bigger than an 11.5x4 because the engine just get's too hot...I run this thing just lean enough get decent throttle response and enough power to hover. Sometimes it's so rich it takes full throttle to hover, but the engine still heats up. There is no way this can be "good" for the engine.

What do you guys think about this? Has this become a problem for anyone? Anybody thought about it?

What if I were to use a helicopter engine like the O.S. .46 FX-H? Will I have a problem keeping it hot enough? How will the above helicopter engine handle an 11.5x4? How will it compare to the Pro .46?