Newps wrote:
C J Campbell wrote:


New what? Manufacturers? Engines? Planes? I don't know of any Cessnas, Pipers
or Beeches that provide settings for it. Or Lycomings or Continentals.



The Continental IO-550, which is by far the most popular engine now a
days, comes with LOP in the power settings. These come directly from
Continental.


Here's the dope from the people who design, build, suffer the
liability for, and have to pay warranty costs for engines that fail:

http://www.lycoming.textron.com/main...ngEngines.html

An excerpt:

"5. The exhaust gas temperature (EGT) offers little improvement in
leaning the float-type carburetor over the procedures outlined above
because of imperfect mixture distribution. However, if the EGT probe is
installed, lean the mixture to 100oF on the rich side of peak EGT for
best power operation. For best economy cruise, operate at peak EGT. If
roughness is encountered, enrich the mixture slightly for smooth engine
operation."

Another one from the same people:

http://www.lycoming.textron.com/main...erLeaning.html

....and an excerpt from it:

"First we must know that cruise power for Lycoming normally aspirated
engines is generally considered to be 55% to 75% of the maximum power
for which the engine is rated. At these power settings, the engine may
be leaned at any altitude. There has been confusion about the reference
to not leaning below 5000-feet density altitude. Remember that this
reference only applies to those power settings above the cruise range
- those normally used for takeoff and climb. Once cruise power has
been set, leaning to best economy should be standard procedure as
damage to the engine will not occur from leaning at cruise power
settings."

And one about running LOP:

http://www.lycoming.textron.com/supp...ps/SSP700A.pdf

Their website has a huge amount of info available regarding engine
operation.

Dan