newbie and i need advice
Thread Starter
Teching In
Joined: Oct 2009
Posts: 3
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newbie and i need advice i have a 04 gto with and ls1 with CAI, 1 3/4 kooks long tubes, and slp cat back. i am getting ready to do a cam and head swap but i have some concerns before i actually do it.
i have stock bore and i am unsure what cam i want but was considering VRX3
the head i am consider are 243 castings have not been milled but have the following mods. to them
2.08 intake valves
1.60 exhaust valves
1.275 dual springs
max lift .620"
242CC Intake
82CC Exhaust
70CC combustion chamber
my concerns are PTV and CR ... i know the CR will be around 9.5-9.6 with a stock head gasket but i am unsure how detrimental that will be and i'm also concerned with the fact that the valves are larger and could have issues with the valve reliefs in the pistons if i use a different head gasket or mill the heads to up the CR
any and all feedback is appreciated and thanks in advance guys
i have stock bore and i am unsure what cam i want but was considering VRX3
the head i am consider are 243 castings have not been milled but have the following mods. to them
2.08 intake valves
1.60 exhaust valves
1.275 dual springs
max lift .620"
242CC Intake
82CC Exhaust
70CC combustion chamber
my concerns are PTV and CR ... i know the CR will be around 9.5-9.6 with a stock head gasket but i am unsure how detrimental that will be and i'm also concerned with the fact that the valves are larger and could have issues with the valve reliefs in the pistons if i use a different head gasket or mill the heads to up the CR
any and all feedback is appreciated and thanks in advance guys
12 Second Club
Joined: Dec 2008
Posts: 281
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From: A small town, MS
From the experiences my friends and I have had, the 243 heads make good power combined with say a Futral f13 cam or a magic stick 3 or 4. As for the compression ratio, that low will hurt you a little. You could have them angle milled 30 thousandths or so. I'm not sure how that would affect your valve clearance. I do know that with stock Ls1 heads milled 50 thousandths with stock valves and flat top pistons you don't want to go over .590 lift on the cam. But those 243 heads do make good power with the cams above. A friend of mine has a set of ported 243's with a Futral f13 cam and he made 422 rwhp, not sure what his torque number was. It was close to that though. I also don't know if his heads have been shaved. I don't know if that helps but that's the experiences I've had. Good luck with the build.
that intake valve is way too big. I would not do a valve bigger than 2.02 intake. Your going to have clearance issues. I have 243's with stock hollow/sodium filled valves. The cam is an Ed Curtis specked cam and the heads where done at Advanced Induction CHD w/ 921 springs and retainers through an A4 am pushing over 450 rwhp and 420 tq. If you want the info pm me and I'll shoot you my cam specs and set up.
