Long story short, I bought some used heads thinking they would work and save some money and it's probably going to end up costing me more in the end than some new properly set up heads
I'm building 5.7 3.9" bore LS1 solid roller with a dry sump to go road racing. I sent the attached flow sheet (at this point I don't even know if it's accurate) to jones racing and had them do a cam.
Basically as far as I can tell
-heads are made for 4" bore, which isn't too bad and I can live with
-cut for 1.5" spring, which cut into intake ports on one head, probably needs to be welded
-valve guides are worn, and not the smaller 8mm valves
-2.05 valves and I have 2.02
-heads have time serts for the rockers studs, and have been clearenced for bigger pushrods, really the only pro
What I have
-New Pac 1222x springs and seats, and a bunch of Xceldyne shims
-comp tool steel retainers for 11/32 stem, crane -.050 locks, comp seals, useless basically
-New 8mm stainless valves 1.57 exhaust 2.02 intake, cheap stainless ones from straubtech, wouldn't mind upgrading to hollow stem valves
I figure it will probably be $1000 to get these heads sorted out, or should I just buy some new heads and cut my loses. I suppose my local machine should could handle this, but they seem more on the side of factory rebuilds
Worth while to salvage these LS1 heads?
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Worth while to salvage these LS1 heads?
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k1ob.com
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Re: Worth while to salvage these LS1 heads?
The other thing to add to the list is that those heads are not ported properly as the Intake flow backs up between .700" and .750" lift.
Even if you are not running that much lift the heads need to be worked on to correct that , and that will add to the cost.
This all being said , how much room would it take up to just sit them on a shelf for a while just in case of things down the road?
Even if you are not running that much lift the heads need to be worked on to correct that , and that will add to the cost.
This all being said , how much room would it take up to just sit them on a shelf for a while just in case of things down the road?
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
Re: Worth while to salvage these LS1 heads?
What is the head casting #?
Carlquist Competition Engines
Re: Worth while to salvage these LS1 heads?
They are the 862 5.3 truck heads
The cam is .650 lift
These heads seem pretty decent
https://www.texas-speed.com/p-3515-prc- ... heads.aspx
The cam is .650 lift
These heads seem pretty decent
https://www.texas-speed.com/p-3515-prc- ... heads.aspx
k1ob.com
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Re: Worth while to salvage these LS1 heads?
ex son-in-law bought those exact heads. very nice. I did a little cleanup and they work fantastic!
Re: Worth while to salvage these LS1 heads?
I guess our EMC heads weren't properly ported cause they stall and back up on the flow bench ?
And, worse yet, they do it at a lift we were running on the engine.
Randy
Re: Worth while to salvage these LS1 heads?
Would you still choose to set it up that way, if pulling on down low Rpm`s, wasn`t so important to score better numbers on this competition?
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Re: Worth while to salvage these LS1 heads?
How'd they fare with the intake bolted up? - I've seen a few heads that had turbulence issues tested as a bare head, but bolt the intake up & it's gone & they pick up quite a lot in high lift flow.I guess our EMC heads weren't properly ported cause they stall and back up on the flow bench ?
And, worse yet, they do it at a lift we were running on the engine.
If they were turbulent with the intake bolted up that'd be a very interesting thing to think about.
Re: Worth while to salvage these LS1 heads?
Other than sizing for higher RPM, yes, I'd do it the same.Amilcar wrote: ↑Tue Nov 21, 2017 8:41 pm
Would you still choose to set it up that way, if pulling on down low Rpm`s, wasn`t so important to score better numbers on this competition?
It's a myth to believe that just because a port stalls below 1" of lift on a flow bench it has to be bad for power on a running engine.
Randy