Compression help for 383ci
Compression help for 383ci Hey guys,
383ci LS6.
Wiseco 3.903 -32cc pistons
Stock size head gasket.
241 Heads 66cc
How much do we need to Mill the heads to be somewhere between 9:2 - 9:8
Thanks in advance...
Sam.
383ci LS6.
Wiseco 3.903 -32cc pistons
Stock size head gasket.
241 Heads 66cc
How much do we need to Mill the heads to be somewhere between 9:2 - 9:8
Thanks in advance...
Sam.
Stock compression on an LS1 with 241 heads is already 10.1:1. Milling the heads would increase the compression ratio. Unless your pistons are designed for low compression (ie: dished or in the hole), then you'll need lower cc heads (like the 6.0 liter truck heads at 71 cc).
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Joined: Jun 2007
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From: MIchigan
Well you're at 8.35:1 now if you're 383 specs out to a 3.903" bore, 4" stroke, and 6.125" rod.
You'd need to take off .050" to get close to 9:1 - which is an awful lot and could give you problems with manifold fitment and head flow. You could run a Cometic .040" gasket and maybe 5.3L heads and get a little more compression before milling.
You'd need to take off .050" to get close to 9:1 - which is an awful lot and could give you problems with manifold fitment and head flow. You could run a Cometic .040" gasket and maybe 5.3L heads and get a little more compression before milling.
383: 3.905" bore with 4.00 stroke crank, 10cc dish JE pistons .002" out of the hole with cometic gaskets 3.970 X .040" thick and 61cc heads is 11:1 static compression, this is my combination.
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You're gonna have to take alot of material off the heads to be where you want to with your current set-up. I wouldn't advise doing it. Your only option using a 32cc dish is going to be running a 5.3l head and you are still going to have to reduce the combustion chamber cc's about 5cc's which would be around .030" off the heads. Not trying to be the monday morning quarterback but you got to consider piston dish volume when buying the pistons. Your pistons are going to be a problem with getting to the desired compression ratio.
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Thanks for the all the replies guys..
A friend of mine bought the short block used I honestly told him the compression is way low for his setup (YSI) but unfortunately for the price he bought we couldnt pass the deal..
I agree and thats what I told him I also not sure it will help under 16+psi...
Thanks.
Thanks...
Like I said not my engine or setup just helping a friend...
A friend of mine bought the short block used I honestly told him the compression is way low for his setup (YSI) but unfortunately for the price he bought we couldnt pass the deal..
Well you're at 8.35:1 now if you're 383 specs out to a 3.903" bore, 4" stroke, and 6.125" rod.
You'd need to take off .050" to get close to 9:1 - which is an awful lot and could give you problems with manifold fitment and head flow. You could run a Cometic .040" gasket and maybe 5.3L heads and get a little more compression before milling.
You'd need to take off .050" to get close to 9:1 - which is an awful lot and could give you problems with manifold fitment and head flow. You could run a Cometic .040" gasket and maybe 5.3L heads and get a little more compression before milling.
I agree and thats what I told him I also not sure it will help under 16+psi...
Thanks.
You're gonna have to take alot of material off the heads to be where you want to with your current set-up. I wouldn't advise doing it. Your only option using a 32cc dish is going to be running a 5.3l head and you are still going to have to reduce the combustion chamber cc's about 5cc's which would be around .030" off the heads. Not trying to be the monday morning quarterback but you got to consider piston dish volume when buying the pistons. Your pistons are going to be a problem with getting to the desired compression ratio.
Thanks...
Like I said not my engine or setup just helping a friend...
