- Joined
- Aug 9, 2015
- Messages
- 182
- Reaction score
- 38
I once more appeal to the great knowledgeable masters for help.
As many of you know I am coming back after the “surprise you need an engine overhaul” and am getting the new engine wrung out. Just through the formal break in times and stretched her legs on a trip up to Omaha today. While the new motor purrs like a kitten with GAMIs it runs very hot, especially compared to the old one, which had stock injectors. Previously I could use full power 35” / 2700 up to cruise altitude and never crack 360-370 CHT. Now if I don’t pull back to 26” / 2500 almost immediately after getting airborne the CHTs shoot right over 400-410, and at those settings sit right at 390-400. Also, during the break-in raging around at 75% ROP I had to REALLY pour on the fuel to keep it below 380, easily 2-3 gph more than previously. As I am out of the break - in period today I tried to run my go-to 65% LOP settings. Per the JPI 830 I was 40-50 LOP at 60% and regularly bumping up against 395-400. The old engine I would be at 10 LOP at 66-67% running in the 365-370 region. I went ROP and was again burning much more fuel to keep it cool than my old settings.
Clearly there is something amiss, as the motor should just not run that hot at those loafing of settings. I’ve scrubbed my JPI data and have found that where before I was getting 36 GPH FF at Max power, now I’m getting 34.5-35 GPH. Other than that I haven’t had anything else jump out at me, and need advice on things to check with the mech. I will run a GAMI sweep on the way home and see what that comes up with as well. Here is my list, please shoot holes in it.
1. Get T/O FF upped to 36 GPH.
2. Check all baffles and such in the engine bay.
3. Check MAG timing? Could advanced timing cause it to run that hot?
What am I missing?
Grant
As many of you know I am coming back after the “surprise you need an engine overhaul” and am getting the new engine wrung out. Just through the formal break in times and stretched her legs on a trip up to Omaha today. While the new motor purrs like a kitten with GAMIs it runs very hot, especially compared to the old one, which had stock injectors. Previously I could use full power 35” / 2700 up to cruise altitude and never crack 360-370 CHT. Now if I don’t pull back to 26” / 2500 almost immediately after getting airborne the CHTs shoot right over 400-410, and at those settings sit right at 390-400. Also, during the break-in raging around at 75% ROP I had to REALLY pour on the fuel to keep it below 380, easily 2-3 gph more than previously. As I am out of the break - in period today I tried to run my go-to 65% LOP settings. Per the JPI 830 I was 40-50 LOP at 60% and regularly bumping up against 395-400. The old engine I would be at 10 LOP at 66-67% running in the 365-370 region. I went ROP and was again burning much more fuel to keep it cool than my old settings.
Clearly there is something amiss, as the motor should just not run that hot at those loafing of settings. I’ve scrubbed my JPI data and have found that where before I was getting 36 GPH FF at Max power, now I’m getting 34.5-35 GPH. Other than that I haven’t had anything else jump out at me, and need advice on things to check with the mech. I will run a GAMI sweep on the way home and see what that comes up with as well. Here is my list, please shoot holes in it.
1. Get T/O FF upped to 36 GPH.
2. Check all baffles and such in the engine bay.
3. Check MAG timing? Could advanced timing cause it to run that hot?
What am I missing?
Grant
