LS3 head chamber cc
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LS3 head chamber cc Does anyone know for sure what the combustion chamber size is for the LS3/L92 head? Some publications say 70cc and others say 68cc. Also does any body know for sure how much I need to mill the head to get a 65cc chamber? I have read .025 and also read .030. Is the "rule of thumb" .006 per 1cc? I'm putting my LS3 heads on my LQ9 6.0 and I want to run 10.9 compression , same as LS2. thanks
Does anyone know for sure what the combustion chamber size is for the LS3/L92 head? Some publications say 70cc and others say 68cc. Also does any body know for sure how much I need to mill the head to get a 65cc chamber? I have read .025 and also read .030. Is the "rule of thumb" .006 per 1cc?
.006" per cc
sorry bud dont mean to jack your thread here just curious,how much can you safely mill off of these heads? i have -12cc pistons with untouched 821s and the power just isnt there, thinkin of millin this winter. would like to get to 11.1-11.5.1 can this be done with milled heads and a thinner gasket than what im using now?(.051)
jason
jason
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chamber size Most reports I've seen says 70cc, and to get to 68cc you need to mill .012, and for 65cc you need to mill.030. I guess when I take my heads to the machine shop I'll get them to measure the cc first, then mill them .012 and measure again, then mill .018 more (.030 total) and measure again, then we will know for sure.
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Stock is 68cc give or take 1cc. A good porter can mill them .020-.030, sink the valves a tad and you'll still have some decent PTV clearance.
FWIW, I've done a 223/235 115 on LS3 castings cut .030. Had .060 intake clearance and .080'ish exhaust. Runs good.
FWIW, I've done a 223/235 115 on LS3 castings cut .030. Had .060 intake clearance and .080'ish exhaust. Runs good.
Last edited by Damian; Sep 5, 2010 at 12:49 AM.
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From: REALITY
duals or behive springs?
Looks like the LSL lobes
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chamber cc Ok, I got my heads back from the machine shop, stock chamber size was 68.5 cc, they then milled them .030 and the chamber size is now 63cc., stock LS2 has 64.5 cc heads and flat tops and 10.9 compression, my engine should come in about 11.1:1 compression ratio, engine is LQ9 6.0, flat tops. thanks for all the input guys,
It is LSL lobes. Those lobes work real well with the LS3/L92 heads.
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From: REALITY
Close is fine if you've got a light weight valve and good spring. In that type of scenario I'll run them .050-.060 clearance on the intake without any worries. Those springs were "PSI" springs. Single beehive and will hold .650 all day.
It is LSL lobes. Those lobes work real well with the LS3/L92 heads.
It is LSL lobes. Those lobes work real well with the LS3/L92 heads.
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From: Katy, TX
Ok, I got my heads back from the machine shop, stock chamber size was 68.5 cc, they then milled them .030 and the chamber size is now 63cc., stock LS2 has 64.5 cc heads and flat tops and 10.9 compression, my engine should come in about 11.1:1 compression ratio, engine is LQ9 6.0, flat tops. thanks for all the input guys,
