Worth while to salvage these LS1 heads?

[ctk30]

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

[mag2555]

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?

[BILL-C]

What is the head casting #?

[ctk30]

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

[mark_follweiler]

ex son-in-law bought those exact heads. very nice. I did a little cleanup and they work fantastic!

[randy331]

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 ,

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

[Amilcar]

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 ,

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

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?

[KnightEngines]

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.

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.

If they were turbulent with the intake bolted up that'd be a very interesting thing to think about.

[randy331]

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 ,

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

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?

Other than sizing for higher RPM, yes, I'd do it the same.

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