We have about 60 hours on our 9A which has a brand new (well, 60 hours) IO-360. As we have a Dynon FlightDEK 180 with full engine monitors, we can safely run lean of peak, and of course we try to do so based on the "leading" cylinder.
There is a "guy" at our airport who tends to know lots of stuff, and he said leaning for LOP operation is easy--once in level flight just turn a full turn out, wait a few seconds, monitor the EGT's and CHT's, watch for LOP operation on the engine monitor, get to the back side of the curve and when you turn the knob and experiencerough operation, enrichen to smooth running. This process generally comports with running 50 degrees LOP on the leading cylinder, so its a good rule of thumb that we tend to follow.
As for descent, I generally run LOP until the last 3 or 4 minutes of flight when I just enrichen all the way for the approach. I do lean pretty aggresively on idle and during taxi.
These things have started bothering me, though, since I read an article this month in Aviation Consumer Magazine about spark plugs. While extolling the virtues of the more expensive thin wire plugs, the article quotes some engine shops which state that one of the best ways to promote detonation, and thus cause undue wear on an engine, is to lean slowly (like I do) or to just fully enrichen on descent (which I do.)
I don't want my $23,000 engine to weare unnecessarily, and everything that I read in Aviation Consumer I tend to believe. So, am I leaning incorrectly? In other words, how do you lean "quickly?" I can just picture leveling off at 6500 feet and yanking out the mixture knob and killing the engine.
And if I don't enrichen fully the last few minutes of flight, how am I supposed to enrichen upon descent, especially within a few minutes of landing?
dahugo
There is a "guy" at our airport who tends to know lots of stuff, and he said leaning for LOP operation is easy--once in level flight just turn a full turn out, wait a few seconds, monitor the EGT's and CHT's, watch for LOP operation on the engine monitor, get to the back side of the curve and when you turn the knob and experiencerough operation, enrichen to smooth running. This process generally comports with running 50 degrees LOP on the leading cylinder, so its a good rule of thumb that we tend to follow.
As for descent, I generally run LOP until the last 3 or 4 minutes of flight when I just enrichen all the way for the approach. I do lean pretty aggresively on idle and during taxi.
These things have started bothering me, though, since I read an article this month in Aviation Consumer Magazine about spark plugs. While extolling the virtues of the more expensive thin wire plugs, the article quotes some engine shops which state that one of the best ways to promote detonation, and thus cause undue wear on an engine, is to lean slowly (like I do) or to just fully enrichen on descent (which I do.)
I don't want my $23,000 engine to weare unnecessarily, and everything that I read in Aviation Consumer I tend to believe. So, am I leaning incorrectly? In other words, how do you lean "quickly?" I can just picture leveling off at 6500 feet and yanking out the mixture knob and killing the engine.
And if I don't enrichen fully the last few minutes of flight, how am I supposed to enrichen upon descent, especially within a few minutes of landing?
dahugo