how much compression gain?
TECH Addict
Joined: Dec 2001
Posts: 2,298
Likes: 2
From: new england
Re: how much compression gain? On a 5.7 head .007" is 1cc of chamber reduction, which is around .1 point in compression. So 10.1 comp. shaved .007" would be 10.2 to 1 compression. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Re: how much compression gain? My calcualations are a little bit different than LS1derfull but I suppose close enough. When you mill stock head .025, the compression goes from 10.2 to 10.8 on a stock head.
On The Tree
Joined: Jun 2002
Posts: 116
Likes: 0
From: new york
Re: how much compression gain? I have found the same thing, milling .oo7 is .1 compresion increase and -.720 cc's. I came up with an equation that I use for figuring compression ratio for the stock ls1 that figures in stock head gasket thickness, ring land, and deck hight... 618.475+ {chamber cc's}divided by {chamber cc's} ex. 618.475+63cc's/63cc's=10.817063
there is a longer equation I use when figuring other variables and for my forced induction heads. Milling .035 on a stock head and valves will give you 10.8 to1, My stg2 heads get 10.8 to 1 with .025 mill and larger valves{2.02-1.575}
there is a longer equation I use when figuring other variables and for my forced induction heads. Milling .035 on a stock head and valves will give you 10.8 to1, My stg2 heads get 10.8 to 1 with .025 mill and larger valves{2.02-1.575}
