Power setting table and best economy/best power...

"Ron Rosenfeld" wrote in message
...
Some comments regarding your assertions.

They aren't assertions. I'd prefer to call them suggestions. I am
theorizing, at best, not being an expert in this field, nor having any solid
data one way or the other. But thank you for your contribution.

[...]
So to claim that there is "higher operating temperature" causing "some
additional engine wear" without noting that, other than in the immediate
exhaust area, the engine operating temperature is actually lower, and the
power pulse pressure waveform is less destructive, seems to me to be
overlooking essential data.

I cannot find the post I could swear I posted, in which I suggested that
detonation, rather than excessive temperatures, is the greater and more
genuine hazard. Maybe that post was in a different thread (leaning at
altitude?).

You are certainly in good company to claim that at leaner settings, the fuel
burns more evenly and more gradually, and that overall temperatures are
lower. I don't have an engine monitor, but those who do have told me that
peak EGT and peak CHT don't occur at the same mixture setting.

One would probably still want to be concerned about detonation however.
It's destructive no matter what the temperature.

Of course, some engines are unable to run at peak EGT or LOP EGT due to
imbalances in fuel or air flow. If an operator is not operating any
leaner
than, let us say, 25°F RICH of peak EGT, he may indeed cause increased
wear
and tear on his engine at those settings. I believe the original (1965)
manual for my Mooney recommended that setting for best economy. But I do
not believe that either of the current engine (or airframe) manufacturers
still make that recommendation.

Make which recommendation? To use 25°F rich of peak EGT for best economy?
Are you saying that they no longer recommend a setting that might be
hazardous to the engine? Or that they no longer think that there might be a
hazard at some other setting?

It seems to me that absent fuel-flow matching, any setting in the
neighborhood of peak EGT (rich, lean, or exactly on) runs roughly the same
risk of engine damage (assuming there's a risk of engine damage at all).
Without having an all-cylinder monitor, one doesn't know what the other
cylinders are set to. Any best-economy setting at high enough power
settings seems to me likely to incur some additional wear-and-tear or actual
damage.

Pete