Captain,

It gets done all the time, I didn't say I was condoning it. I agree with you, for break in all you need to do is generate enough cylinder pressure to seat the rings. All that takes is short bursts of power, not continuous WOT. Alternating throttle settings and making sure the engine is not overloaded or overheating is more important than WOT for any length of time. I think it is done because it is easy to crank it up on the stand and let it rip, whereas you can't normally fly around at WOT for long in the air.

I do recall Ralph C mentioning that the T-6 racers will break in a G-62 by putting it on the stand with a race prop on and letting it run WOT for a couple of gallons, though. Of course, that prop doesn't load the engine too heavily and lets it rev pretty high. And I am sure they know enough to not let it get too hot along the way.

Mark