: I take it you are familiar with John Deakin's columns on the topic and
: engine management in general at avweb.com?

These articles basically say:

- LOP done improperly *WILL* damage engines. Only at 75% or less can it be done
safely.
- Absolute EGT doesn't matter... CHT primarily controls detonation margin, top end
longevity, and exhaust valve temperatures. (Lycoming and Cont have too high of
redlines... 400 CHT is as high as should be periodically seen... 375 max continuous)
- ANY leaks in ANY valves are unacceptable and will cause damage, LOP or not.
- ROP provides the most power for a single "power setting" (i.e. MP+RPM setting...
*actual* power setting also includes the mixture). Thus marketing likes ROP since it
makes the plane go faster on paper.

I use these articles (and Lycomings recommendations) to operate my 180 hp
Lycoming O-360. It's carb'd so LOP doesn't quite get there. Below 75%, I can do
anything I want with the mixture so long as CHT stays cool enough. I typically
consider 65% power and 350 CHT my maximums. At those settings, I can lean to
where there is a noticable power loss, but before it's rough, and 8-8.5 gph.

-Cory

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************************************************** ***********************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
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