Quote:
It would help if you knew the current compression. With CR we can make a pretty good guess if the engine will be octane limited and less timing will be a neccessary work around. Do know the cc after the heads were cut?
The compression ratio is now 10.07 to one. The chambers are 82.5 ccs after polishing the chambers, unshrouding the valves and the resurfacing the decks. Beforehand on 91 octane, it knocked even with total timing limited to 31 degrees. Running 110 octane it ran fine without any knocking. Currently I have total in at 33 using 91 again and so far it hasn't detonated. I've read specs from other guys big blocks and seen anything from 32-38 degrees total timing being used. I see ro reason to run more timing than the engine needs.
Lots to digest here. I'm printing this one out to read in the shop!
*******************************************************************
looking at that Demon carburetor site, according to their spec sheet, my initial timing should be right between 18-20 degrees. My cam is a 261/271 degrees @ .050 solid flat tappet Lunati.
Last edited by Frankenduster; 01/19/14 07:24 PM.
