Oil deposits can reduce the octane of fuel pretty substantially. 11.5 is higher than I would try though. I just got a little greedy going from 10.5 to 11, while closing up the LSA by 3 degrees. At 10.5 with a 110 LSA the motor was pretty happy but now I'm pulling timing. I knew I shouldn't have changed both at once, but the quest for just a little more power consumed me.

Are the heads open chamber still or milled closed?

Last edited by GTX MATT; 02/10/20 01:56 PM.
Now I need to pin those needles, got to feel that heat
Hear my motor screamin while I'm tearin up the street