<< you wrote:

Typical piston engine leaning
procedure is to lean until is runs rough, then richen up until it smoothes
out. This is very dangerous. Uneven distribution may have you running way
over lean on one cylinder and at ideal mixture (for max power) on another.

If

the richer cylinder has not been equipped with a cylinder head temp lead,

you

can be melting that one while thinking you are going easy on the engine.

Hello Lynn,
Is "richer" above supposed to be "leaner"?
Also, do you happen to have the URL for Paul Yaw?
Thanks,
Doug

No. The cylinder with the ideal mixture for maximum power (rich of peak EGT)
will produce the most power and the most heat. It will also produce the
highest wear
rates on the rings, cylinders, and bearings. It will also dilute the oil with
the most blowby. It will also shorten plug life and on the way require a
number of plug cleanings and regappings. The idea that running lean some how
damages engines has come about because we take off at full rich (although few
airports are at sea level) and after a full throttle climb, level off and
get out the maps and a candy bar and start dialing in the radio for the next
contact.......oops better lean this baby down.....So you do what? You have
one (maybe)

EGT gage probe and your book says 1575.....but you noticed 6 years ago that
it runs a bit stronger (more RPMs)at 1550. In fact you give up almost 50 RPMs
at 1575, so 1550 it is. Running the measured cylinder at a lower EGT may have
left two cylinders at ideal mixture, pounding hard and hot. If gas was a lot
cheaper, and it didn't cost $17,000 to overhaul the big Continental then 1550
or 1500 would be just fine. Notice how some engines never seem to make it to
TBO? The EGT probe must be on the cylinder that runs the hottest. Since that
may not always be the same one engine to engine, or installation to
installation, then we should have a probe on every cylinder. It would also be
nice to see the cylinder head temp of all cylinders during this time. once
you establish which cylinder has the highest temps you can measure just that
one. Most people are doing this now. So now you can lean to hottest cylinder
to 1550 not just "a" cylinder. Now you can watch all of the temps and lean to
say 100 degrees lean of peak
on the hottest (highest EGT) cylinder. You will loose a very small amount of
power. You will be far less likley to crack a case or drop a valve or shock
cool a cylinder or melt out a spark plug hole. Your engine will love you for
this. Cylinder head and oil temps will come down.

I can't type out Mr. Yaw's URL because it has a "tildy" in it and I don't
have one on my keyboard, but go to "Google" search engine and type in
"Yawpower" it will take you right there. If you want to waste some time, take
Google to Lynn E Hanover and look at my page.

 
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