Four Valve Heads Anyone?
Originally Posted by Reckless
I would listen to what Kurt (427) has to say, he builds these engines for a living. Not to mention he will be my boss in a few weeks 
Cast a C5R head with or without valves and come up with a cast intake to fit and you will have a winner. The smaller bore guys can stay with stock stuff if they want to.
Cast a C5R head with or without valves and come up with a cast intake to fit and you will have a winner. The smaller bore guys can stay with stock stuff if they want to.
If you have a 4in bore you have the option of going to the C5R heads.Although I'd imagine they are pretty pricey.
Actually, if anyone is considering C5R heads, they already likely have a 4"+ bore. A C5R head with smaller vlaves to fit the 3.9" bore would lower their advantage against Stage III 2.08"/1.60" heads.
Yes C5R heads are expensive------$1,000-$1,300 each depending on prep. I think the CNC complete heads are $2,300 each, but I think they were discontinued.
Check Scoggin Dickey in the sponsors listing----->
Yes C5R heads are expensive------$1,000-$1,300 each depending on prep. I think the CNC complete heads are $2,300 each, but I think they were discontinued.
Check Scoggin Dickey in the sponsors listing----->
personally i wouldnt bother, just from the fact of chevy building engines with two valves and 16pushrods going well over 400 horse, what kind of gains could 4valves per cyl do. im a ford tech(with a 00z28) i look at how the cobras are four valves per cyl and make less power than a ls1, maybe its just ford buuilding them i dont know, im not trying to biss ford right now but thats the way i look at it, anyway if you do build these heads good luck and let us know the power gains
Also, I think the smaller 3.9" bore is a good reason to go 4 valve.......2 smaller valves would flow as much if not more than a single big vlave and not be as affected by shrouding or the hitting the cylinder wall 
.
Silver6sp, I know where you are coming from. I don't know if the Ford motors have poor ports, the small bore, or what the reason is that they don't make more power than they do
. I think the ports themselves do not flow nearly as much as an LSx head. If schmidtworks can design a 4 valve head with a port like the LSx already has; I think he will have a winner 
.
Schmidtworks----would the 4 valve head also have a centrally located sparkplug? I would think that you could still have the sparkplug and boot come through the top of the cylinder head making plug swaps easier
. I know this was an idea with the hemi-style head, just wondering if the same would be done with a 4 valve design.
.Silver6sp, I know where you are coming from. I don't know if the Ford motors have poor ports, the small bore, or what the reason is that they don't make more power than they do
. I think the ports themselves do not flow nearly as much as an LSx head. If schmidtworks can design a 4 valve head with a port like the LSx already has; I think he will have a winner .Schmidtworks----would the 4 valve head also have a centrally located sparkplug? I would think that you could still have the sparkplug and boot come through the top of the cylinder head making plug swaps easier
. I know this was an idea with the hemi-style head, just wondering if the same would be done with a 4 valve design. 
TECH Senior Member
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Originally Posted by Silver6sp
personally i wouldnt bother, just from the fact of chevy building engines with two valves and 16pushrods going well over 400 horse, what kind of gains could 4valves per cyl do. im a ford tech(with a 00z28) i look at how the cobras are four valves per cyl and make less power than a ls1, maybe its just ford buuilding them i dont know, im not trying to biss ford right now but thats the way i look at it, anyway if you do build these heads good luck and let us know the power gains
TECH Addict
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I think you will find that making these heads will be a waste of money and a futile effort. Especially if by some freakish chance the new 24-valve heads will bolt on to an LS1. Then you will quickly find yourself broke. I have a wonderful idea though...for anybody that would like to do it.
How about a cam install tool, just like the JPR rods, except made out of ABS plastic. That should make them incredibly cheap to make, just as effective at keeping the lifters up, and guarantee that you will not chip or scratch any of the metal parts inside your engine. I particularly like the cheap part because then the savings can be passed on to us.
How about a cam install tool, just like the JPR rods, except made out of ABS plastic. That should make them incredibly cheap to make, just as effective at keeping the lifters up, and guarantee that you will not chip or scratch any of the metal parts inside your engine. I particularly like the cheap part because then the savings can be passed on to us.
Teching In
Joined: Apr 2004
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sounds good.... This is just a thought, but could you not use a few design aspects of the Lotus-designed LT5 DOHC heads? You might also look at the Northstar DOHC V8s. These things definately need to be able to handle gobs of boost and/or nitrous. Thick decks are a must. For the issue of keeping low-end torque, make the ports flow well as-cast, but leave the walls thick enough for porting for the top-end junkies who don't mind losing the low-end. These heads would also produce a great wow factor when you pop the hood. The blue oval guys with their whining snakes won't know what hit 'em!!!! Good luck.
-ThaBant
'78 Camaro w/ LS1 & 6sp
-ThaBant
'78 Camaro w/ LS1 & 6sp
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My $.02:
A DOHC head is going to be a mess to package.
A hemi head is going to be a mess to package and need all kinds of nonsense (coil relocation, intake manifold, exhaust manifold, etc...).
How's about a better C5R head and an intake to match?
Word of advice:
Rumors flying around the LS2 are saying that the intake has been revised to match the C5R layout, which will kill dead any of the aftermarket intakes. If that head is as good as it looks to be AND increases the headroom for the intake relative to max power, AND bolts up to LS1's, there is going to be hell to pay in the aftermarket.
Every intake, ported head, AFR head and a host of other parts will become obsolete overnight.
Find out what GM is doing. Holley didn't, came up with a marginal design, and the LS6 intake wiped out their market.
A DOHC head is going to be a mess to package.
A hemi head is going to be a mess to package and need all kinds of nonsense (coil relocation, intake manifold, exhaust manifold, etc...).
How's about a better C5R head and an intake to match?
Word of advice:
Rumors flying around the LS2 are saying that the intake has been revised to match the C5R layout, which will kill dead any of the aftermarket intakes. If that head is as good as it looks to be AND increases the headroom for the intake relative to max power, AND bolts up to LS1's, there is going to be hell to pay in the aftermarket.
Every intake, ported head, AFR head and a host of other parts will become obsolete overnight.
Find out what GM is doing. Holley didn't, came up with a marginal design, and the LS6 intake wiped out their market.
Originally Posted by PacerX
My $.02:
A DOHC head is going to be a mess to package.
A hemi head is going to be a mess to package and need all kinds of nonsense (coil relocation, intake manifold, exhaust manifold, etc...).
How's about a better C5R head and an intake to match?
Word of advice:
Rumors flying around the LS2 are saying that the intake has been revised to match the C5R layout, which will kill dead any of the aftermarket intakes. If that head is as good as it looks to be AND increases the headroom for the intake relative to max power, AND bolts up to LS1's, there is going to be hell to pay in the aftermarket.
Every intake, ported head, AFR head and a host of other parts will become obsolete overnight.
Find out what GM is doing. Holley didn't, came up with a marginal design, and the LS6 intake wiped out their market.
A DOHC head is going to be a mess to package.
A hemi head is going to be a mess to package and need all kinds of nonsense (coil relocation, intake manifold, exhaust manifold, etc...).
How's about a better C5R head and an intake to match?
Word of advice:
Rumors flying around the LS2 are saying that the intake has been revised to match the C5R layout, which will kill dead any of the aftermarket intakes. If that head is as good as it looks to be AND increases the headroom for the intake relative to max power, AND bolts up to LS1's, there is going to be hell to pay in the aftermarket.
Every intake, ported head, AFR head and a host of other parts will become obsolete overnight.
Find out what GM is doing. Holley didn't, came up with a marginal design, and the LS6 intake wiped out their market.
The C5R head is a race type head. There is a picture of one in this thread.
The LS2 will bolt on the same port as a LS1. I put one on a 346 road race engine that made 523 hp @ 6900 at the flywheel, it picked up to 540 hp still @ 6900. The LS2 has a fly by wire 90mm throttlebody with a 4 bolt pattern. I think the 90mm throttlebody was where most of the gains came from as they are all above 5000 rpm.
Kurt
The LS2 will bolt on the same port as a LS1. I put one on a 346 road race engine that made 523 hp @ 6900 at the flywheel, it picked up to 540 hp still @ 6900. The LS2 has a fly by wire 90mm throttlebody with a 4 bolt pattern. I think the 90mm throttlebody was where most of the gains came from as they are all above 5000 rpm.
Kurt
Originally Posted by 1CAMWNDR
That is pretty good advice. What is different about the C5R layout? The LS2 intake will not have large enough ports to bolt to C5R heads will it? I think a 4 valve pushrod head that bolts to the LS2 intake might be a winner.
Launching!
Joined: Apr 2002
Posts: 240
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From: Michigan
I like the idea of the C5R style head, but I would like to see it work on a smaller bore motor. I know I would personaly rather have a cylinder head capable of flowing 360+ cfm, and not have to spend all the money for a big bore block. It would allow us to make much higher power levels and not have to invest as much money. I know the Yates head for a SBF on a 352 cubic inch motor make a lot of power, why couldin't we do somthing similar on a LSx based motor with the larger bore.
The plug is different. I am going to find out if the 90 can be wired in, but it does not look good.
Kurt
Kurt
Originally Posted by 66ImpalaLT1
Will the LS2 throttle body be electrically compatible with current C5's?
Sorry to take this thread off track.
Sorry to take this thread off track.
Kurt always gets the fun stuff to play with 
That LS2 manifold is pretty beefy looking. Saw it Saturday when I stopped by.
If it were my investment it would be easy, C5R cast head with thick decks and a cast two piece intake to fit the heads. Two piece would allow easy porting and polishing. Make the intake compatible with current fuel rails, etc.
That LS2 manifold is pretty beefy looking. Saw it Saturday when I stopped by.If it were my investment it would be easy, C5R cast head with thick decks and a cast two piece intake to fit the heads. Two piece would allow easy porting and polishing. Make the intake compatible with current fuel rails, etc.
Adkoonerstrator
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From: Deep in the seedy underworld of Koonerville
Why don't we all just wait for the AFR 225s to come out and see how much flow can be pulled outta them. Maybe they got enough meat to carve a C5R type port in them??
Maybe they got enough meat to carve a C5R type port in them??
Originally Posted by XLR8NSS
Why don't we all just wait for the AFR 225s to come out and see how much flow can be pulled outta them. Maybe they got enough meat to carve a C5R type port in them??
Maybe they got enough meat to carve a C5R type port in them??
Adkoonerstrator
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From: Deep in the seedy underworld of Koonerville
Originally Posted by PacerX
Because AFR is proposing a rape-job $2600 for their 205 head that can only handle .550 lift without an added cost spring upgrade.
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From: At the office
Originally Posted by PacerX
Because AFR is proposing a rape-job $2600 for their 205 head that can only handle .550 lift without an added cost spring upgrade.
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From: Deer Park
As many have stated, why fix what's not broken? We are getting killer #'s out of the stock heads. It's the intake that is slowing us down. Why not do the R&D on some killer new intake designs? MAybe something along the lines of a mass produced sheetmetal intake with a large plenum and short runners.
A Victor style FI intake for the LSx's would be awesome.
The stock heads are good adn they are working, but there is more potential there, AFR is working it out. Maybe you could make a street head affordable- (relatively) small runners, high velocity for us stock cube guys...
A Victor style FI intake for the LSx's would be awesome.
The stock heads are good adn they are working, but there is more potential there, AFR is working it out. Maybe you could make a street head affordable- (relatively) small runners, high velocity for us stock cube guys...