'68 Arrow 180. About 1200 hours with about 150 on top. Strong compressions lifter clearance setup correctly. Plugs good, correct, injectors good, recently checked during annual. Injection servo overhauled about 100 hours ago setup properly. Engine has LASAR it has worked flawless for the 10+ years I have owned the aircraft otherwise box stock firewall forward. Baffles good, worn but sealing #4 was tightened up and sealed before trip.
Recent trip TUL to SOW direct. OSA temps in 80's at altitude in the low 60's. Departing and climbing from a 700' altitude and climbing to 8500' on a cool morning all normal, EGT rich to 5000' then about 150 ROP to cruise altitude. Climb was made to 10,500 for terrain WOT and 2500 set about 100ROP.
Departing SOW, 7000' runway 6900' elevation at 65 degrees and just leaned a bit from rich for altitude CHT #4 was a problem most of the way to altitude, 9500. It was a problem in cruise climb as well in other direction. The temp on #4 would climb to 430 easily temp had to be managed with mixture, enrichen, then that would kill the climb.
Browsing the POH which I know to be fiction (!) this aircraft has a useful ceiling of 14'000 which, frankly, I doubt it could ever see with out prolonged low climb rate and managing the mixture to maintain the CHT with the nose very high.
The question...other than airflow i.e. baffles and inner-cylinder baffles, injector being lean, what could cause such a problem to occur? I might note that the other jugs ran, worse case, 30-50 degrees lower. I ran LOP 20-25 degrees on the number 4 in cruise the other jugs fell 5-10 LOP the jugs ran very cool, 340-375 in cruise. It is the climb and the use of more power that is killing the usefulness of this aircraft. While I normally do not live at high altitudes the use of the aircraft in areas of altitude leave it anemic and with a high workload.
Any thoughts??
Recent trip TUL to SOW direct. OSA temps in 80's at altitude in the low 60's. Departing and climbing from a 700' altitude and climbing to 8500' on a cool morning all normal, EGT rich to 5000' then about 150 ROP to cruise altitude. Climb was made to 10,500 for terrain WOT and 2500 set about 100ROP.
Departing SOW, 7000' runway 6900' elevation at 65 degrees and just leaned a bit from rich for altitude CHT #4 was a problem most of the way to altitude, 9500. It was a problem in cruise climb as well in other direction. The temp on #4 would climb to 430 easily temp had to be managed with mixture, enrichen, then that would kill the climb.
Browsing the POH which I know to be fiction (!) this aircraft has a useful ceiling of 14'000 which, frankly, I doubt it could ever see with out prolonged low climb rate and managing the mixture to maintain the CHT with the nose very high.
The question...other than airflow i.e. baffles and inner-cylinder baffles, injector being lean, what could cause such a problem to occur? I might note that the other jugs ran, worse case, 30-50 degrees lower. I ran LOP 20-25 degrees on the number 4 in cruise the other jugs fell 5-10 LOP the jugs ran very cool, 340-375 in cruise. It is the climb and the use of more power that is killing the usefulness of this aircraft. While I normally do not live at high altitudes the use of the aircraft in areas of altitude leave it anemic and with a high workload.
Any thoughts??
