I'm new to gas engines, just bought a bme 50. Ive put about 1-2 gallons of fuel through it on the ground (its 15 degrees in wisconsin, way to dam* cold to fly...).

I'm getting worried about all of these reports I hear about prop strikes. I consider myself a good pilot (fly heli's, some jets, etc), but I do fly from a small field. On the smaller planes (ie saito 91, 180, os 160) propstrikes are common! You only need to hit one little rut in the ground and it noses over.

Am I to assume that if this happens with my bme 50, with the motor at idle, I will bend the crank???? That is a frightening thought???!!! Am I over reacting? Are we talking more about prop strikes at full throttle? I would think that a Zinger prop would break long before the crank was twisted...no?

Ive seen large warbirds have multiple prop strikes on the same day (don't those wonderful retracts fail frequently ), and no problems occured.

Should I be cutting the engine prior to landing???

With a wood prop and at idle, its a minor problem. At WOT and a carbon fiber prop a much bigger problem.
Most prop strikes don't bend the crank, but twist it around the crank pin.
Zenoahs are the easiest to damage, the BME in in the middle. A Fox or Brison are almost impossible to damage with a prop strike, cantilevered cranks.

I would say some one correct me if I am wrong but 95% of the time at idle with a wood prop you are probably OK. But it never hurts to get a dial indicator and check the crank shaft to be safe. Hope this helps.

Having a single bolt prop hub also helps. The prop will rotate slightly on a strike.
If it was a 3W, ZDZ or a DA, there is no give on a prop strike as they have 6 bolt hubs.

TKG has it right. If the crank is multipiece pressed together, any sudden stops twist the flywheel around the crank pin. This could be a problem on any multi-cylinder engine. All of the ZDZ (and DA) singles use a cantilevered (one piece) crank.

On the motorcycle engines with ball bearing cranks, before they would take 'em racing, they would weld the crank to prevent it from twisting.

Is there any benefit in converting a 6 bolt hub to a single bolt hub?

In general, the only people who can find an advantage to a single bolt hub, are the ones that own an engine with a single bolt hub. It costs more money to make a mutli bolt hub, and it's not too likely that DA, 3W, ZDZ and Moki all converged on the same costly "bad idea". They did it because it's a well-proven design adopted from full scale practice. Slipping props are not a "good thing". Would you put aluminum bolts on the wheels of your car so you could bounce your car off curbs without bending the axles?

Also, all of the 6 bolt hubs use a 10mm prop shaft designed to fit the props without drilling the center hole (Mejzlik, Menz, Air Models, Fuchs, Engel, MSC, Bolly, AirWild).

I have a Sachs engine and I plan to make my own jig in hte next week or two. I just hope i don't bust a propeller before then.