krines
MEMBER
Billings
Top overhauled my o-320 b2b with Lycon port and polished cylinders. Initially on engine break in I saw EGT 1500 full rich at max power OAT 40F with CHT that would hit 425 easy at full power. Was a little concerned about the 1500 temp so called Lycon and they recommended the 10-5217 carb which would deliver more fuel for the increased air flow with the port and polish. With the 10-5217 now I see max EGT 1425 full rich with CHT's at 375 to 385 at OAT 30F density altitude 3000. I have searched this forum about this issue and a lot of attention was paid to baffles but to me it made logical sense that with increase airflow through the cylinders one would see a lean mixture with the -32 carb. Sutton exhaust. Fuel flow at max power take off 11.2 with 2500 cruise about 8.2 . Lycon folks provided excellent service. Out the other day testing it all out and shooting dogs and it just seemed that I was ripped off the ground. Also when I first took off I thought this engine sounded so smooth but I could have been smoking crack. So this is just a report from the field that if you are going to port and polish be prepared to pay attention to your carb.