Lean of Peak

[cjordan]

My 73G NA with Gamis will run LOP ~100. I never do this above 65%, or for long, just tests as only a single egt/cht. It seems if 65% or less (usually here 65% or less at cruise altitudes if going somewhere) it’s safe to just run peak egt. Basically follow the Mike Busch method, but more conservative at peak.

[Dr.Dan]

I have an engine monitor but still using stock injectors. My engines will not run LOP with the current injectors; the spread is too great. I would like to put GAMIs in it so that I could cruise LOP with lower CHT.

[hharney]

Originally Posted by Dr.Dan

I have an engine monitor but still using stock injectors. My engines will not run LOP with the current injectors; the spread is too great. I would like to put GAMIs in it so that I could cruise LOP with lower CHT.

C337C NA, Gami's, JPI Engine Monitor, and Fine Wire Plugs. I can set up for lean of peak at cruise using the JPI. Typically 9,000 ft, WOT, 2400 RPM lean about 40 to 60 degrees lean of peak and see about 14-15 GPH total. I will lose 10 kts GS at these settings. I can run same settings at 50 degrees ROP and see 18-19 GPH and back to my normal 155 - 160 kts TAS. I don't see the savings in running LOP. At 9,000 to 11,000 ft when operating at LOP the airplane is lethargic, especially if facing head winds. Watching the GS at 125 - 130 kts at LOP against the head winds just makes no sense to me. Airspeed is not the most important factor here to go across the country but I can't sit and watch those speeds.

The cylinders are cooler, maybe 25 - 30 degrees cooler.

Be careful running at Peak, you should be 60% HP or less. Remember Mike Busch says the most dangerous part of adjusting for fuel flow is when you are in the red box or shark fin

I have flown other planes, A36 w/550, Cirrus, Lancair, Navajo and these planes operate totally different when using LOP ops. Except the Navajo where those are run nomal at Peak not LOP