"Jay Honeck" wrote in message
ups.com...
From what I've been reading on the Mooney list by Walter Atkinson, LOP
is
a Good Thing, and even doable on carbureted engines (one needs to play
with the carb heat setting, an engine analyzer and a carb temp gauge
are
de rigueur).

A touch of Carb heat and the throttle cracked ever so slightly. It
creates
turbulence in the intake system that evens things out rather nicely.

Care to expand on that?

http://www.avweb.com/news/columns/182085-1.html

"Carbureted Engines, and Fixed-Pitch Props
The single most-asked question I've had from these engine management columns
has been some wistful variant of, "But what about my 182, which has a
carbureted engine?" Or, "What about my 172, with its fixed-pitch prop?"

Folks, I'm really sorry, there's just not that much that can be done, beyond
a few simple tips that have been commonly used for years, like leaning on
the ground (see below).

Here's another tip for carbureted engines only. When operating at full
throttle, it is often helpful to back off on the throttle until you see just
the tiniest drop in MP (if you have a MP gauge, otherwise look for the
slightest drop in RPM), and leave it there instead of fully open. That cocks
the throttle plate just enough to set up a slightly turbulent flow, and that
helps mix the fuel and air for better combustion. A touch of carburetor heat
may help, too.

But I've flown a couple of 182s that are simply hopeless, and I'm tempted
just to leave the mixture full rich and forget it. Pity, the Skylane is a
marvelous airplane, but that TCM O-470 engine has the worst mixture
distribution of any powerplant on the planet.

If you're fortunate to have an all-cylinder engine monitor on a carbureted
engine, see if you can operate lean enough to get all cylinders lean-of-peak
(LOP) without the engine jumping off its mounts from vibration. I haven't
seen one that would yet, but there may well be some engines that will do it.
If so, some of this column may be helpful.

While the knowledge of these things may be helpful in a general way for
everyone who flies, it is only the high-performance, fuel-injected engines
that allow some of the more sophisticated techniques. Even on those, it
almost always takes GAMIjectors to make these tricks work well enough to use
them at all. This is the primary reason you have not seen some of this
information in the past - it simply hasn't been very useful, and there's
been no need for it.

Once again, this column will refer entirely to normally-aspirated engines,
unless otherwise noted. Yes, yes, I know, there are two or three turbo
owners out there who want me to do a column for them, and I'll get to it,
one day, I promise (but I'm not saying when!)"