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[EMAIL PROTECTED] wrote:
>
> Would some one be kind enough to explain
> step by step just how the EGT gage is used
> to lean the aircraft?


1. Get the plane in stable condition, i.e. level flight, stable climb,
or clean run-up pad.

2. Set the power setting you want.

3. Slowly pull out the mixture knob, watching the EGT gauge.

4. At some point, as you continue to pull, the gauge will peak and the
EGT will start to lower -- even though you are continuing to pull the
knob to lean the engine.

5. Now you push the knob back in. The EGT will rise to the peak and then
cool as you continue to push it in.

6. For best power, my book says 100 degrees on the rich side of peak
(pushing in).  For cruise, they say 50 degrees on the rich side of
peak.  The Voyager, flying around the world without refueling, flew on
the lean side of peak, watching it all the time with good instruments to
be sure they didn't get so lean as to get detonation.

With my Stromberg carb, I make the changes pretty slowly and watch to
see the change in temp. It is NOT a fast response control like the
throttle.

With the designed fuel/air mix, the fuel burns in a smooth wave front
producing the power over some amount of time. An excessively lean
mixture burns way too fast, like an explosion front and can damage the
engine parts from the force of the detonation.

Some people lean by sound and RPMs on the tachometer. I found I couldn't
identify the peak well at all this way. I had a really wide area of knob
pulling and pushing with little apparent change.

My EGT has the BIG scale which lets me have three or four needle widths
for each 10 degree increment and I can very accurately identify the peak
and the 50 or 100 degree rich-of-peak setting. Recommended.

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