Italiancowboy
Active Member
So in my RV6 fixed pitch prop O-320, I only had one EGT and so basically I used my training-days method of leaning: lean until the engine stumbles then give it 1 1/2 turns. That made sure you were on the LOP side then enrich toward Peak a little (keeps you away from too lean and give a little power back).
So now in my RV10 with O-540 CS Prop and EGTs on each cylinder with Dynon monitoring, I can do real leaning . . . if I know what I'm doing.
I've read EI's Pilot Manual for Leaning and Diagnosing Engine Problems and understand the Power, CHT, and Fuel Flow curves.
It's been easy to run "Best Power" ROP with the leanest cylinder 100F ROP. But boy does that burn fuel.
So trying to go to "Best Economy" and run the richest cylinder at 30-80F lean of peak has been a problem. As I lean the EGTs rise but I never seem to get to EGT Peak before the engine starts to stumble; they continue to rise as I lean. I know the CHTs have some lag (lots of metal there to change temp) but EGTs should change pretty quickly. If I enrichen from the stumble, the EGTs go down indicating to me that I'm still on the ROP side.
Fuel flow at 8000ft, 20MP/2100rpm is just less than 10gph at the stumble while leaning. Fuel pressure is good (5 psi).
So educate me. What am I missing ? Am I still on ROP side ? How do I get over the peak ?
So now in my RV10 with O-540 CS Prop and EGTs on each cylinder with Dynon monitoring, I can do real leaning . . . if I know what I'm doing.
I've read EI's Pilot Manual for Leaning and Diagnosing Engine Problems and understand the Power, CHT, and Fuel Flow curves.
It's been easy to run "Best Power" ROP with the leanest cylinder 100F ROP. But boy does that burn fuel.
So trying to go to "Best Economy" and run the richest cylinder at 30-80F lean of peak has been a problem. As I lean the EGTs rise but I never seem to get to EGT Peak before the engine starts to stumble; they continue to rise as I lean. I know the CHTs have some lag (lots of metal there to change temp) but EGTs should change pretty quickly. If I enrichen from the stumble, the EGTs go down indicating to me that I'm still on the ROP side.
Fuel flow at 8000ft, 20MP/2100rpm is just less than 10gph at the stumble while leaning. Fuel pressure is good (5 psi).
So educate me. What am I missing ? Am I still on ROP side ? How do I get over the peak ?