Super-budget head suggestions
02-06-2012, 08:45 PM
#1
Super-budget head suggestions I want to put together a set of good stock heads. Right now I have a set of 317 heads, but I want to move to a 243 or a 799 to get my compression ratio up. Any suggestions?
Right now, my plan is to buy a set of 799 heads off of a 2004 truck for $200 and have a valve job done. I already have 918 springs and Ti retainers. The only thing that worries me is the mileage on the heads - I can't tell for sure what the mileage is.
Also, are the car valves better than truck valves? I seem to remember reading somewhere that the truck valves were made from two pieces, where the car valves were made from a single piece of steel and were better. Is this true? I have a set of 806 perimeter-valve cover heads from a 1998 Corvette with about 55k on them - I could probably use those valves if they would be better.
Is there any reason to buy heads from a newer 5.3 truck rather than an older one? Did some years come with better valves, springs, etc?
BTW, it's a boosted setup so I'm not so worried about CNC porting, etc - just looking for an economical and reliable solution.
Right now, my plan is to buy a set of 799 heads off of a 2004 truck for $200 and have a valve job done. I already have 918 springs and Ti retainers. The only thing that worries me is the mileage on the heads - I can't tell for sure what the mileage is.
Also, are the car valves better than truck valves? I seem to remember reading somewhere that the truck valves were made from two pieces, where the car valves were made from a single piece of steel and were better. Is this true? I have a set of 806 perimeter-valve cover heads from a 1998 Corvette with about 55k on them - I could probably use those valves if they would be better.
Is there any reason to buy heads from a newer 5.3 truck rather than an older one? Did some years come with better valves, springs, etc?
BTW, it's a boosted setup so I'm not so worried about CNC porting, etc - just looking for an economical and reliable solution.
02-06-2012, 11:29 PM
#2
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What is your compression now?
Usually it is better/cheaper to increase boost rather than compression.
I believe the ports on the 317s are identical to the 243/799 so total flow (or resistance to boost) will not change.
Anything above 9.0/1 I think I'd live with.
Turn up the volume (boost), cool the intake charge, go faster!
The only thing you leave on the "table" this way is a tiny tiny improvement in off boost performance and MAYBE a tiny amount of fuel economy.
Resistance to detonation under pressure will suffer with this change. If you have detonation under control to the point of increasing your static compression ratio then increasing boost level is the path to greater power.
On the other hand 200 for a pair of 799s is a GOOD deal....
I'm a believer of starting with the very best cores you can purchase. I recently purchased a pair of new stock LS2 799s but I paid double for this feature!
If you're talking about serious boost then after market valves are the way to go. All you should care about is the quality level of the castings and the wear on the valve guides. Everything else gets chucked!.
I purchased a set of lightly used Z06 valves for my brand new heads as they are lighter which should allow better valve control at high RPM but I'm not boosted. The sodium filled exhaust valves MIGHT help a boosted application's reliability but I don't think the hollow stem intakes would make any difference at all.
I would probably install inconel exhaust valves and stainless intakes in a serious FI engine.
Super budget only goes so far. Spend money where it's needed. you already have some of the better head castings.
Heads-machine work-head gaskets/bolts, and all the other things that you will hit changing your heads could be better spent on an inter-cooler or a meth/water injection system if you don't already have them.
Usually it is better/cheaper to increase boost rather than compression.
I believe the ports on the 317s are identical to the 243/799 so total flow (or resistance to boost) will not change.
Anything above 9.0/1 I think I'd live with.
Turn up the volume (boost), cool the intake charge, go faster!
The only thing you leave on the "table" this way is a tiny tiny improvement in off boost performance and MAYBE a tiny amount of fuel economy.
Resistance to detonation under pressure will suffer with this change. If you have detonation under control to the point of increasing your static compression ratio then increasing boost level is the path to greater power.
On the other hand 200 for a pair of 799s is a GOOD deal....
I'm a believer of starting with the very best cores you can purchase. I recently purchased a pair of new stock LS2 799s but I paid double for this feature!
If you're talking about serious boost then after market valves are the way to go. All you should care about is the quality level of the castings and the wear on the valve guides. Everything else gets chucked!.
I purchased a set of lightly used Z06 valves for my brand new heads as they are lighter which should allow better valve control at high RPM but I'm not boosted. The sodium filled exhaust valves MIGHT help a boosted application's reliability but I don't think the hollow stem intakes would make any difference at all.
I would probably install inconel exhaust valves and stainless intakes in a serious FI engine.
Super budget only goes so far. Spend money where it's needed. you already have some of the better head castings.
Heads-machine work-head gaskets/bolts, and all the other things that you will hit changing your heads could be better spent on an inter-cooler or a meth/water injection system if you don't already have them.
02-07-2012, 08:28 AM
#3
Thanks for the info!
The absolute only reason I want to get rid of my 317's is to get my CR up. Right now, my CR is about 8.5:1. I want to bring it up to about 9:1 because of the reasons you pointed out. Also, I have a TVS1900 from a Cadillac CTS-V, and that engine runs at about 9:1 CR, so I figured I could mirror that and be in good shape.
I don't think I am going to go crazy with boost. I am thinking stock valves will be fine, but I am a little concerned about reusing the stock valves. Are all LS1 valves (2.00 and 1.55) the same, except for the Z06 valves?
I was a little worried about the valve guides, too... I'll have to find out what the mileage is on these heads.
The absolute only reason I want to get rid of my 317's is to get my CR up. Right now, my CR is about 8.5:1. I want to bring it up to about 9:1 because of the reasons you pointed out. Also, I have a TVS1900 from a Cadillac CTS-V, and that engine runs at about 9:1 CR, so I figured I could mirror that and be in good shape.
I don't think I am going to go crazy with boost. I am thinking stock valves will be fine, but I am a little concerned about reusing the stock valves. Are all LS1 valves (2.00 and 1.55) the same, except for the Z06 valves?
I was a little worried about the valve guides, too... I'll have to find out what the mileage is on these heads.
02-07-2012, 09:32 AM
#5
I have a stock 98-99 Camaro cam, and I really don't want to take it out. I am worried that if I get my heads milled, I will need new pushrods (already have Comp Camps hardened pushrods) and I think it will throw off the geometry of my intake manifold, which I don't want to take any chances with.
The way things are looking, I will be able to get a set of good used heads and a valve job for about $300. I bet I can sell my 317's for somewhere around there!
The way things are looking, I will be able to get a set of good used heads and a valve job for about $300. I bet I can sell my 317's for somewhere around there!
02-07-2012, 11:09 AM
#6
