Ron Lee
Well Known Member
Today I went up to 13,500' to be well above the 75% engine power area and tried to operate the engine lean of peak. This is a rebuilt O-360 using Superior cylinders, 9.5:1 pistons and the cylinders ported and flow matched to very close tolerances by Ly Con.
I have been running EGT around 1330 degrees F. Continue to lean and watch the EGT increase and then around 1400 degrees F it actually started decreasing with further leaning while still running smoothly.
I have never been able to do this.
Around 1340 degrees on the lean side of peak I noticed a power drop (apparent) then the normal roughness. Fuel flow at this time was around 7.3 gph (full throttle) and 8.5 gpg around 1330 degrees rich of peak.
Since I had one Lightspeed EI before the engine rebuild I am surmising that the flow matching process is solely responsible for now being able to run lean of peak in a carbureted O-360.
I forgot to see if the cylinder head temp dropped but will try it again to better understand any issues. Comments and suggestions welcome.
I have been running EGT around 1330 degrees F. Continue to lean and watch the EGT increase and then around 1400 degrees F it actually started decreasing with further leaning while still running smoothly.
I have never been able to do this.
Around 1340 degrees on the lean side of peak I noticed a power drop (apparent) then the normal roughness. Fuel flow at this time was around 7.3 gph (full throttle) and 8.5 gpg around 1330 degrees rich of peak.
Since I had one Lightspeed EI before the engine rebuild I am surmising that the flow matching process is solely responsible for now being able to run lean of peak in a carbureted O-360.
I forgot to see if the cylinder head temp dropped but will try it again to better understand any issues. Comments and suggestions welcome.