Engine out practice

"Stefan" wrote in message
. ..
Matt Barrow schrieb:

Thomas offers data and evidence, Lycoming offers anecdote and legend.
Lycoming offers running engines. Thomas offers words.

Try something other than "Argument from Authority", such as EVIDENCE.

Evidently, Lycoming knows how to build engines. Evidently, Lycoming has a
lot of experience by looking at used engines while overhawling them. I
don't know how many engines Thomas has built or overhauled. I don't even
know where his data comes from and how it was collected.

Lycoming's take is based on legal protection of it's assets, not the engine
owners.


Or, if you can show that Lycoming HAS NOT been shown to frequently be
FOS,

No idea what a FOS should be. Please write in a language I understand.

It took them quite a while to recognize the :OP was not a disaster in the
making. GAMI's engine stand data pretty much showed both Lycoming and TCM to
be way off base. GAMI did years of hard research, Lyc and TCM did their
appraisals based on what their legal counsel recommended, not their
engineers (who evidently didn;t even understand the engine stroke sequence.)


then you can make their case.

I'm not making anyone's case. In fact, I couldn't care less, as I'm happy
enough to operate a liquid cooled engine with 21th century technology.

A heavier engine is SOTA?

Also, how does a liquid cooled engine vary from the physics of an engine
sequence?

No small wonder that aviation is the home of so many myths, legends, and
OWT's.

--
Matt Barrow
Performance Homes, LLC.
Cheyenne, WY

wrote:
Matt Whiting wrote:
Jay Honeck wrote:
The issue with shock cooling isn't the rate of cooling per se, but
rather stress induced by differential cooling.
Actually, I think it is the rate of cooling *and* the differential
cooling -- if it exists at all. Like you, I am skeptical -- but am I
willing to bet $25K on it? Nope.
How does the rate affect things? I have a masters in structural
engineering and work for a materials company so don't be afraid to get
technical. :-)
How 'bout this: It's the disparate rates of cooling in some parts of
the engine (versus others) that causes the differential cooling that
induces stress?

Yes, that is what I said originally. It is differential cooling that
causes the problem, not the rate of cooling itself. If you could cool
the entire engine uniformly, I don't think it would matter much how fast
you cooled it.

It isn't the rate itself that causes a problem, it is the difference in
rates from one location to another. However, I still think that the
greatest thermally induced stress occurs during the initial heat-up from
a cold start, but I don't have any data to confirm that and I don't have
an instrument airplane with which to collect the data.

Matt

I would think the greatest thermally induced stress occurs when you fly
into rain.


That may well be, but probably only for the front two cylinders. I
wonder if the front cylinders have a higher failure rate than the rest?

Matt

Stefan wrote:
Matt Barrow schrieb:

Thomas offers data and evidence, Lycoming offers anecdote and legend.

Lycoming offers running engines. Thomas offers words.

And Lycoming benefits if your engine lasts fewer hours.

Matt

Matt Barrow schrieb:

I'm not making anyone's case. In fact, I couldn't care less, as I'm happy
enough to operate a liquid cooled engine with 21th century technology.

A heavier engine is SOTA?

You have not the slightest idea what engine I'm talking about, yet you
know that it's heavier. Wow. Now if everything else you wrote is based
on the same profound knowledge, I better skip your comments.

Matt Whiting schrieb:

And Lycoming benefits if your engine lasts fewer hours.

So avoiding shock cooling actually lowers its life span? Wow.

Matt Whiting wrote:
wrote:
Matt Whiting wrote:
Jay Honeck wrote:
The issue with shock cooling isn't the rate of cooling per se, but
rather stress induced by differential cooling.
Actually, I think it is the rate of cooling *and* the differential
cooling -- if it exists at all. Like you, I am skeptical -- but am I
willing to bet $25K on it? Nope.
How does the rate affect things? I have a masters in structural
engineering and work for a materials company so don't be afraid to get
technical. :-)
How 'bout this: It's the disparate rates of cooling in some parts of
the engine (versus others) that causes the differential cooling that
induces stress?

Yes, that is what I said originally. It is differential cooling that
causes the problem, not the rate of cooling itself. If you could cool
the entire engine uniformly, I don't think it would matter much how fast
you cooled it.

It isn't the rate itself that causes a problem, it is the difference in
rates from one location to another. However, I still think that the
greatest thermally induced stress occurs during the initial heat-up from
a cold start, but I don't have any data to confirm that and I don't have
an instrument airplane with which to collect the data.

Matt

I would think the greatest thermally induced stress occurs when you fly
into rain.


That may well be, but probably only for the front two cylinders. I
wonder if the front cylinders have a higher failure rate than the rest?

Matt

Hmmm, thinking about it a bit, any shock cooling should be worse on
the front two cylinders rain or shine.

An analyse of failure rate by cylinder position would be interesting.

--
Jim Pennino

Remove .spam.sux to reply.

wrote:
Matt Whiting wrote:
wrote:
Matt Whiting wrote:
Jay Honeck wrote:
The issue with shock cooling isn't the rate of cooling per se, but
rather stress induced by differential cooling.
Actually, I think it is the rate of cooling *and* the differential
cooling -- if it exists at all. Like you, I am skeptical -- but am I
willing to bet $25K on it? Nope.
How does the rate affect things? I have a masters in structural
engineering and work for a materials company so don't be afraid to get
technical. :-)
How 'bout this: It's the disparate rates of cooling in some parts of
the engine (versus others) that causes the differential cooling that
induces stress?
Yes, that is what I said originally. It is differential cooling that
causes the problem, not the rate of cooling itself. If you could cool
the entire engine uniformly, I don't think it would matter much how fast
you cooled it.
It isn't the rate itself that causes a problem, it is the difference in
rates from one location to another. However, I still think that the
greatest thermally induced stress occurs during the initial heat-up from
a cold start, but I don't have any data to confirm that and I don't have
an instrument airplane with which to collect the data.
Matt
I would think the greatest thermally induced stress occurs when you fly
into rain.


That may well be, but probably only for the front two cylinders. I
wonder if the front cylinders have a higher failure rate than the rest?

Matt

Hmmm, thinking about it a bit, any shock cooling should be worse on
the front two cylinders rain or shine.

An analyse of failure rate by cylinder position would be interesting.


Yes, my thought exactly. I wonder if anyone keeps such data? I know
when I owned my Skylane, we never had any unusual issues with the front
two cylinders. This data, if available, would certainly provide some
indication if shock cooling is real or imagined.

Matt

Stefan wrote:
Matt Whiting schrieb:

And Lycoming benefits if your engine lasts fewer hours.

So avoiding shock cooling actually lowers its life span? Wow.

You have no evidence that following Lycoming's recommendations avoids
the mythical shock cooling demon or that it lengthens engine life. My
experience is that the engines that are run the hardest also last the
longest. I'm basing this on everything from chainsaws to lawnmowers to
motorcycles to cars to trucks to off-road heavy equipment (dozers,
skidders, etc.) to airplanes (trainers, air taxi operations, cargo).

I'm personally not convinced that Lycoming's recommendations lengthen
engine life.

Matt

In article ,
wrote:



Hmmm, thinking about it a bit, any shock cooling should be worse on
the front two cylinders rain or shine.


It was the rear cylinders that would alarm on my monitor. They're
hotter and are the farthest from ambient temp.

Stefan wrote:

Lycoming says otherwise:


The engine manufacturers are about the last place I'd look for engine
management techniques.