wrote:

Personally, I simply lean a fixed-pitch prop Lyc to find peak rpm and
have never had any performance or maintenance issues in nearly a decade
of flying. The engine always seems happy and I suspect that at peak
rpm, I'm probably still blowing a significant amount of unburned fuel
out the exhaust pipe. In those planes I've flown that were equipped
with cht guage, the temps never climbed high enough to be worrisome
either.

Here's a chart:

http://www.swaircraftappraisals.com/MeyersForum/Engine%20Info/Engine%20Operation/Pelican's%20Perch%20Mixture%20Magic_files/pp18d.jpg

The horizontal axis is leaning (left is leaner, right is richer). The
highest point of the BHP curve is peak power -- notice how close it is
horizontally to the highest point of the CHT curve, which represents
the hottest your engine gets.


All the best,


David