alpinelakespilot2000
Well Known Member
I'd appreciate comments on a lean range test I did today. I have done it previously, but had not been able to do it WOT (as it should properly be done) until I had my prop repitched. It has been repitched and here are my results:
Test conditions:
WOT
8000' MSL
~9500' DA
-Made 4 runs, starting at full rich and taking about 6-8 minutes to slowly lean until all 4 cylinders peaked. Then went to full rich, allowed temps to stabilize, repeated the process 4 times.
Average EGT delta between full rich EGT and peak EGT:
Cylinder #1: 173.3F
Cylinder #2: 107.8F
Cylinder #3: 251.0F
Cylinder #4: 229.8F
The order in which each cylinder reached peak was always 2-1-4-3 and the standard deviation for each cylinder on all four runs above was within +/- 10F, so I'm pretty sure I got some accurate averages.
Average fuel flow delta from first peak to last peak was 1.14gph so, as expected, running LOP is tough, though I will experiment with some carb heat to see if that helps.
My main concern, especially given how high up I was, #2 seems to be running really lean (and that cylinder does generally run hot relative to the others) but anything else I can take from these numbers and/or should do or check for?
Thanks.
Test conditions:
WOT
8000' MSL
~9500' DA
-Made 4 runs, starting at full rich and taking about 6-8 minutes to slowly lean until all 4 cylinders peaked. Then went to full rich, allowed temps to stabilize, repeated the process 4 times.
Average EGT delta between full rich EGT and peak EGT:
Cylinder #1: 173.3F
Cylinder #2: 107.8F
Cylinder #3: 251.0F
Cylinder #4: 229.8F
The order in which each cylinder reached peak was always 2-1-4-3 and the standard deviation for each cylinder on all four runs above was within +/- 10F, so I'm pretty sure I got some accurate averages.
Average fuel flow delta from first peak to last peak was 1.14gph so, as expected, running LOP is tough, though I will experiment with some carb heat to see if that helps.
My main concern, especially given how high up I was, #2 seems to be running really lean (and that cylinder does generally run hot relative to the others) but anything else I can take from these numbers and/or should do or check for?
Thanks.
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