My wife getting scared

It isn't obvious, Jay, and you haven't produced any evidence that it is a
fact. Maybe it *is* bad for an engine, but you haven't even said what damage
you think is being done.

Our insisting on evidence for a claim like that is not at all remarkable. I,
and I know Thomas, insist on empirical reasons for things we will believe.
Why does that seem strange?

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.

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.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay Honeck wrote:

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.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"





This is really the crux of this issue. It's not the touch and go's per
se' that are the real issue, but rather the way an aircraft engine is
managed. In the training environment, it is not uncommon to have many
different pilots and different instructors all managing an engine
differently instead of with a standardized procedure.
It's for this direct reason that every pilot and instructor who ever
flew our airplanes was subjected to as an integral part of our checkout
procedure, an in-flight demonstration on how we wanted our engines
managed throttle wise UNDER NORMAL NON EMERGENCY CONDITIONS.
Smooth throttle and prop use use and in relevant cases correct use of
cowl flaps is the key to long engine life. 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.
Aside for an emergency condition, any application of power up or down
that isn't smooth indicates poor planning on the part of the pilot.
DH
--
Dudley Henriques

"Jay Honeck" wrote:

I think you're just going on gut feeling, and you know...

So, you're saying that running your engine from 900 to 2700 RPM over
and over again is no worse for it than running at 2300 RPM all day?

Oh no you don't, Honeck! ;^)

1) I never said that.

2) You still haven't answered the questions: Why is "running your engine from
900 to 2700 RPM over
and over again" harmful? What parts of the engine are harmed and how?

Be sure and show your work.


--
Dan
T-182T at BFM

It's for this direct reason that every pilot and instructor who ever
flew our airplanes was subjected to as an integral part of our checkout
procedure, an in-flight demonstration on how we wanted our engines
managed throttle wise UNDER NORMAL NON EMERGENCY CONDITIONS.
Smooth throttle and prop use use and in relevant cases correct use of
cowl flaps is the key to long engine life. 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.
Aside for an emergency condition, any application of power up or down
that isn't smooth indicates poor planning on the part of the pilot.

Amen, brother!

Thanks for restating it in better terms, Dudley.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay Honeck wrote:
Can we agree that idle power/full power engine management will cause
more wear and tear (AKA: "Damage") to an engine than steady-state
operation?
No. Why?

I'm no thermodynamist, but I believe it's commonly accepted that
taking an internal combustion engine from steady state/low RPMs to
full power/high RPMs (as one would repeatedly do during touch & goes
and engine-out practice) is more harmful to the engine than simply
steady-state/mid-RPM power settings.

A rough analogy would be to think of drag racers versus rally car
engines. One lasts 20 to 30 seconds, the other lasts 1000 miles.

And one makes more horsepower PER CYLINDER than the rally car makes in
total!

Matt

Dudley Henriques wrote:
Jay Honeck wrote:

I'm no thermodynamist,

.....and owning your own hotel, it's an odds on bet you didn't sleep at
a Holiday Express last night ether!!!!!!!
:-))
D


Oh, that was a low blow! :-)

Matt

Jay Honeck wrote:
I think you're just going on gut feeling, and you know...

So, you're saying that running your engine from 900 to 2700 RPM over
and over again is no worse for it than running at 2300 RPM all day?

Yes, I would say that. When I was learning to fly, the C-150 engines
ran longer with less problems than did the 172 and 182 and they DID run
like this all day long.

Matt

Jay Honeck wrote:

I do believe this thread proves the old Usenet adage that "anyone will
argue anything". For you to be questioning the rather obvious fact
that high-power/low-power engine operations are harder on an aircraft
than steady-state engine operations illustrates a remarkable, um,
quality.

Jay, this simply isn't an "obvious fact" and I'm not convinced it is a
fact at all. You have provided one mechanic who thinks your way and
several of us have provided mechanics who disagree. This is hardly the
scenario that would surround an "obvious" fact.

Matt

"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

Jay,

but I believe it's commonly accepted that
taking an internal combustion engine from steady state/low RPMs to
full power/high RPMs (as one would repeatedly do during touch & goes
and engine-out practice) is more harmful to the engine than simply
steady-state/mid-RPM power settings.


Judging from the thread, it's not that accepted, it seems.

--
Thomas Borchert (EDDH)