what 72cc factory head for my 402 on 15#'s max?
10-28-2011, 06:26 PM
#1
what 72cc factory head for my 402 on 15#'s max? Hey guys, i'm just getting back into the LS game yet after being away for a few years til the beginning of this one but just dropped the coin yesterday on a used kytp kit and to help fund the project, i'll be selling my heads and depending if i go square port, my intake too.
What heads would be a good match for my 402 thats mostly driven and only sees the track a couple times a year? As far as i know, the 317's are still favored for a budget and have the 72cc chambers to get me down to 10:1cr but are there any good square port heads i can get opened up to 72+cc? Also, i'm not looking to have to swap valves too because as i said, its a budget build.
Thanks for any input!
What heads would be a good match for my 402 thats mostly driven and only sees the track a couple times a year? As far as i know, the 317's are still favored for a budget and have the 72cc chambers to get me down to 10:1cr but are there any good square port heads i can get opened up to 72+cc? Also, i'm not looking to have to swap valves too because as i said, its a budget build.
Thanks for any input!
10-29-2011, 07:50 AM
#2
ok so if i go square port, it looks like as long as i keep the boost to 15# max, either the l92 or ls3 heads will work as long as i get the chambers opened up a few cc. is there a preference of 1 over the other for a FI setup?
If i wont see any hp/tq gains then i will go with the 317's.
If i wont see any hp/tq gains then i will go with the 317's.
Last edited by PRAY HRD; 10-29-2011 at 08:07 AM.
10-29-2011, 08:14 AM
#3
LS3/L92 heads are already 70cc from the factory. They don't like too much boost because they tend to lift with their thin deck (5/8)
You can try a set of LSA heads which are a factory casting but have a thicker deck but for the price of them you could just get a set of PRC LS3 aftermarket casting heads. They both might be out of your budget so you are back to square one with either stock casting L92/LS3 heads or 317 heads
veee8 on here ran 15 psi on them and they started to lift but to look at the other end of the spectrum cjg454 on here was running e85 and was taking them to 20+ psi the last I remember. I don't know if the e85 was helping keep the heads down or what.
You can try a set of LSA heads which are a factory casting but have a thicker deck but for the price of them you could just get a set of PRC LS3 aftermarket casting heads. They both might be out of your budget so you are back to square one with either stock casting L92/LS3 heads or 317 heads
veee8 on here ran 15 psi on them and they started to lift but to look at the other end of the spectrum cjg454 on here was running e85 and was taking them to 20+ psi the last I remember. I don't know if the e85 was helping keep the heads down or what.
10-29-2011, 09:39 AM
#4
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Im running the L92s on my 403 blown motor with about 12 lbs and havent had any problems. I really like the flow that these heads gave me (I hand ported them.) for the cost. You can pick up a brand new bare set for about 500-600 ea.
10-29-2011, 04:57 PM
#5
true but i can open up the chambers to the 72 pretty easily and reach my goal maximum CR. and agreed, they will be out of my budget.
i wonder if the difference was the amount of back pressure each one saw. would 15psi with a bigger a/r have eliminated veee8's issue?
how much power are you putting down if you don't mind sharing daniel?
i wonder if the difference was the amount of back pressure each one saw. would 15psi with a bigger a/r have eliminated veee8's issue?
how much power are you putting down if you don't mind sharing daniel?
10-30-2011, 12:22 AM
#6
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802 rwhp at 5800 rpm. I also might re-add that the intake ports are different, need a different manifold. this was not a concern for me bc of the sc...In terms of flow, i really did not see any pair of head for the same pice range that could compare.
ps. I have a good friend that is running the L92 heads on a 454lsx with twin gt4088s at 25+ psi and he has put many a 9 sec passes and over 9000 miles on the motor with no pushed gaskets, flow problems, or any setbacks.
ps. I have a good friend that is running the L92 heads on a 454lsx with twin gt4088s at 25+ psi and he has put many a 9 sec passes and over 9000 miles on the motor with no pushed gaskets, flow problems, or any setbacks.
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10-30-2011, 09:48 AM
#8
As far as veee8 having any backpressure issues, I don't think he was having any at only 15psi. He had a large turbo on the car at the time but I just can't remember the A/R of the exhaust housing. I also think he was running a pretty aggressive tune on the car which was also causing it to lift.
I say run them and keep the boost low, then upgrade later on. Who knows, TFS will probably have their LS3 heads out by then and you could put on a set of them and really make some power.
I say run them and keep the boost low, then upgrade later on. Who knows, TFS will probably have their LS3 heads out by then and you could put on a set of them and really make some power.
10-30-2011, 05:03 PM
#10
I got my LSAs bare brand new for $315 shipped. I bought the LSA valves seperate for $140 I believe, and the patriot Extremes for $240... all together = $695, which leaves you a bit of room for porting if you wanted to. You can run them as cast and port them later if you're on a small budget.
If you want the place where I got them, I can PM you. They take about 2 weeks to ship though.
Wrong. It's an internet myth that you can't run high boost with L92/LS3 heads. You can run 23-25 with a good tune, and a well built motor (LS9 head gaskets, ARP head and main studs) without pushing water.
If you want the place where I got them, I can PM you. They take about 2 weeks to ship though.
Wrong. It's an internet myth that you can't run high boost with L92/LS3 heads. You can run 23-25 with a good tune, and a well built motor (LS9 head gaskets, ARP head and main studs) without pushing water.
Last edited by westtexasbuff; 10-30-2011 at 05:11 PM.
10-30-2011, 05:48 PM
#11
I got my LSAs bare brand new for $315 shipped. I bought the LSA valves seperate for $140 I believe, and the patriot Extremes for $240... all together = $695, which leaves you a bit of room for porting if you wanted to. You can run them as cast and port them later if you're on a small budget.
If you want the place where I got them, I can PM you. They take about 2 weeks to ship though.
Wrong. It's an internet myth that you can't run high boost with L92/LS3 heads. You can run 23-25 with a good tune, and a well built motor (LS9 head gaskets, ARP head and main studs) without pushing water.
If you want the place where I got them, I can PM you. They take about 2 weeks to ship though.
Wrong. It's an internet myth that you can't run high boost with L92/LS3 heads. You can run 23-25 with a good tune, and a well built motor (LS9 head gaskets, ARP head and main studs) without pushing water.
yea please do! i need to open them up to 72cc. think there's enough meat in the chambers to accomplish this safely? i have head and main studs and will be about 10:1cr and a t6 turbo so bp should be good with the right a/r. speed inc will probably do the tune.
10-30-2011, 09:06 PM
#15
Also my cousin had a similar setup but with less compression and twin 60 mm with Meth and no intercooler made 780 rwhp at 12 Psi. These heads are amazing for high HP low boost applications.
10-31-2011, 08:02 AM
#19
If it was me I wouldn't run LS3/L92 heads regardless, I would just use the LSA or the PRC LS3's since they are available.
