"Jay Honeck" wrote

Borchert would argue that black-eyed beans are really black-eyed peas,
just for the sake of arguing. His arguing a point has little to do
with anything, real or imagined, other than that he enjoys the sound
of his own voice.

As for you looking for "proof" that rough-handling an engine isn't
worse for it than treating it with kid gloves, well, Dan, I don't know
what to tell ya. I guess we'll just have to agree to disagree on this
one.

Jay, I think you would agree that I am not an overly argumentative person,
and that I'm a pretty fair wrench turn'er. (remember me putting in a
transmission into my van, in the field at Oshkosh? g)

What Dudlley said in the next post is pretty much my view on the whole
thing. Quote by The Dud:

It's the smooth management of temps and pressures up and down that's
important, and this means strict focus on how power is transitioned from
idle to full and visa versa.

End quote.

On the subject of going from idle to full power, that covers it all. If you
treat the engine with the temp and pressure in mind, it really does not care
if it changes RPM often. All day long if you wanted to. Exceeding cylinder
pressure limits wear the piston, rings, and cylinders, and put extra strain
on the rod and main bearings.

Think of it like this. If you are cruising along at cruise with the engine
making 70% power, that is still a lot of HP being made, and pressure is
being applied to all of the moving parts of the engine, and a lot of it, at
that.

If you accelerate an engine nicely, you do not put as much pressure on it,
and it is not making as much HP as it would be subjected to at cruise power
settings. Therefore it won't hurt the engine, following those guidelines.

The problem with training planes is that renters don't apply the power
smoothly, or watch the temperatures, and end up lugging it, and putting
extra pressure on everything. THAT is what hurts engines that are going
from low power to high power.

You care about the life of your engine, and if you are aware of possible
pitfalls, you will not hurt your engine.

In conclusion, I would agree that unless you can come up with real numbers
on how touch and goes and such, hurt your engine, I don't think it is
a -given- that low power to high power cycles hurt the engine. If you don't
exceed the cylinder pressures and temperatures, it can't do anything bad,
because the engine is -designed- to output much higher amounts of power for
extended periods of time, and all in an engine that is designed to make its
power at very conservative HP to Cubic Inch levels. This isn't a dragster,
or road racer, making 1 1/2 ot 2 HP per cubic inch, but an engine only
putting out around 1/2 HP per cubic inch. These are very sustainable power
levels.

Here's something I know we all agree on: I will endeavor to practice
engine-out procedures more often -- and (as opposed to our training
days) I will also endeavor to apply power slowly and carefully at the
end of that looooong glide.

That's a good thing, I guess, and if nothing else, it will probably make you
and Mary safer pilots.

Happy flights!
--
Jim in NC