On Thu, 15 Apr 2004 13:34:30 GMT, "Roger Long"
om wrote:

The greatest stress on the engine will be at 50 ROP
which is where Lycoming says to run it.

I am asuming, since your email suggests that you are US based, that you are
talking degrees Farenheit. I agree that 50°F ROP is a bad place to run the
engine.

Which engine does Lycoming say to run 50°F ROP? Lycoming does NOT make
that recommendation for the O360 series of engines.

In my Lycoming O360 series engine manual, the recommendations for normally
aspirated engines a

1. Full Rich for take-off, climb and maximum cruise powers (above
75% power), with a caveat to lean just to a smooth running engine for
take-off from a high-elevation airport or during climb.

2. Maximum Power cruise (75% power): 150°F on the rich side of
peak EGT.

3. Best Economy cruise (below 75% power): operate at peak EGT

For turbocharged engines:

1. Best Economy Cruise: Lean to peak TIT or 1650°F, whichever
occurs first.

2. Maximum Power Cruise: 125°F on the rich side of the temperature
determined in step 1 (peak TIT vs 1650°F).

Certain "airframe" manufacturers may have different recommendations in
their POH's, and those take precedence. But, even though Lycoming states
that a manufacturer's POH takes precedence, that's a far cry from stating
that "Lycoming" says to run the engine at 50°F ROP.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)