Originally posted by OhSigmaChi:
How high can compression go without knocking on 92 octane?
Well in that case I suspect my C/R must be in the 11 range, because it can't use 89 octane any more except on cold days, and I'm pretty sure a good deal more than half a millimeter was removed from my head to correct warpage.
When the engine was reassembled, we measured an average of 160 PSI on a warm day at sea level, and that's with several cc of plumbing attached to the compression guage.
If air pressure was a hair over 15, then 160 would make a ratio of 10.5, and if there were 5 cc of slack in the tubing, that would make somewhere around 11.1 as the actual C/R... I think the plumbing slack may well have been more than that.
This is supposed to help give me tire roasting power, but somehow it's a bit less powerful than before the rebuild. Could it be that the computer just doesn't know what to do with 11:1 compression?
