Using gm mls what cc for 11.0
Why only 11:1? With valve reliefs and a big cam I would definitely bump the compression up...it's free horsepower. Also I would run a thinner gasket to tighten the quench up.
Just for reference I am running a 61.5 cc head with a .045 cometic...compression is around 11:4.1. The motor will run 13.8 afr with 27 degrees timing and not detonate on pump gas. Only reason I know this is because I had a base tune that looked good, I was not seeing any Kr, but I went ahead and hooked up the wideband to finish tuning and seen right away wot fueling was 13.8. The tight quench is what kept it from detonating...at least that is what I was told.
Just for reference I am running a 61.5 cc head with a .045 cometic...compression is around 11:4.1. The motor will run 13.8 afr with 27 degrees timing and not detonate on pump gas. Only reason I know this is because I had a base tune that looked good, I was not seeing any Kr, but I went ahead and hooked up the wideband to finish tuning and seen right away wot fueling was 13.8. The tight quench is what kept it from detonating...at least that is what I was told.
A tight quench keeps heat away from the ring lands and causes the mixture to swirl a lot more just prior to ignition. On a stock bottom end the .040"-.045" are a great choice and have only upsides. Once you fly cut make sure you don't have any sharp ridges on the pistons. Will create hot spots that and cause pre-ignition.
A properly quenched SBE and the proper Dynamic compression ratio(cam events) can allow 12:1 on pump gas. See Pat G's 500whp recipe.
A properly quenched SBE and the proper Dynamic compression ratio(cam events) can allow 12:1 on pump gas. See Pat G's 500whp recipe.
Last edited by Exidous; Jun 8, 2015 at 03:46 AM.
