John, if you looked into the Forced Induction section here, I am sure you could read an until your eyes bleed about heads lifting and cupping under boost. The Nitrous guys need a solution as well. As for NA, cant say I seen anyone post on that in particular, but flow does mean much to these guys. And 2v simply doesnt flow like a 32v LS1/6 would. Other than ease, or abililty to not have to modify everything else, the deck thickness is the biggest structural obstacle. Chamber sizes now from 66 - 76 are norm. And are you looking into using a new manifold, the LSX or design with stock LS6 type manifold as this will impact also. If it "works" with an LS6, and better with the LSx than that is enough. Good luck and please keep us posted.

Charlie

 

I really think its a great idea,as long as the price is reasonable and the gains are worth the upgrade

 

If you have the investment $ for the R and D, I would expect you could sell them easily as long as they had a few key features...thicker decks, high flow at low port volume, and end with at least 10-15 hp increase over the hot competition at the moment. Many of us bought LSX intakes at 800 plus even with very sketchy results...cause we beleive...and we like new cool stuff... You will never be main stream so expect low sales numbers...so the margin better be good!

Okay, I'll take a set...

 

aaaaaaaaaaakkkkkkkkkkkk!!!!!!!!!

another set of heads i have to wait for the design and results b4 i can by a set...
i been waiting for afr to show there results and was getting down to the wire then i read this.....
so now how can i get the afr heads (if they put 15+hp on the current guys) if there is a chance that these heads will turn around and put down 15+ on THEM !!!!

that being said... i cant wait to see the prototype

 

The boosted guys would probably love a set of 4 valve heads with THICK decks.

 

Thanks for the continued input, I am getting a picture of what you want in a cylinder head.

1. Stronger Decks
2. 20 HP+
3. Simple Install
4. Price under 3K

Will you please give me some input on the following?
Q1. What is the highest compression ratio you would use?
Q2. Is having pistons cut for valve clearance too much work?
Q3. Will special exhaust headers be too expensive @ $600 (guessing)
Q4. Would you rather just have a good canted valve or twisted hemi head with less cost and complcation?

Thanks again for your input, I look forward to your thoughts!

Best Regards

Jon Schmidt
jonathanschmidt@mail.com
www.motorsportsdesign.com
www.schmidtmotorworks.com

 

Hemi heads would be cool, and should also produce great numbers. It'd be more cost efficient, i'd say go for that too.

 

Hemi design would be more than nice, plug change in 15 min or less!
Ok,
1)yes stronger decks
2)20+hp over current ported heads
3)cant really get any simpler than stock, just dont need a 10page install manual ya know.
4)Even 3500 if all else met would still sell, but sure 3k or less is a good goal.

New "?"
1)I would think an average CR of 8.5:1 for boost, and highest of 12:1 for NA/Nitrous. Of course having 2 different chambers like current 66 or 76, with ability to mill solves most of that. There will always be the few that need that 13.25:1 CR or 9:1 etc.
2)I wouldnt say it too much work. There are plenty of ppl here currently doing it with block in car, just to fit a cam! Most boost apps wont need to I dont think, but NA/Nitrous would be another story and most going forged will most likely have a valve relief. But shouldnt be too much work, as long as its known up front unlike some of the recent developments in the LSx community.
3)Headers, thats a bad choice there. Unless absolutely necessary, I would try to keep the factory style/location as much as possible, only if it wasnt feasible. The header industry just came on line this last year, and some of the poor coatings and welding is starting to show its ugly head. As can be seen in some posts in the external section.
4)If you can do a hemi, locating the plug up top centered, I would like that. I am not familiar with benefits of one over the other. Swirling sounds more today tech opposed to Hemi being old school. If they both flowed, and had similar flame propagation, unshrouding etc. then KISS, keep it simple!

Thanks for showing intrest.

Charlie

 

1.--Yes Stronger thicker decks that can withstand 15+ psi of boost.
2.--Yes 15-20+ Hp on current available PORTED heads.
3.--Yes simple install---compatability with current intakes would be nice.
4.--Yes, Under $3,000 if that is feasible.

Q1.--The highest compression is relative to the application; but most heads and cam cars have about 11.0-11.5:1 Compression Ratio.
Q2.--Cutting pistons should not be needed. As stated earlier, two intake vlaves will flow more at .500" than one will flow at .600". Cutting pistons is not needed with current milled heads untill you get to .600" lift or more.
Q3.--Special headers will not be a problem, and if you can get them to us for @$600 that would ROCK!
Q4.--A good flowing hemi head with big valves would be killer. Again, if it does not demand a special intake manifold it would be better.

Sounds like you have great idea here. The 4 valve head would be nice. (Are you talking cam in block with each rocker operating 2 valves ala AERO, or are you talking about a real 4 CAM set-up?) I really like the Hemi idea too. Special Intake Manifolds and Headers will make this very expensive and out of reach for most people, but it sure is cool as **** to think about.

 

Good idea, but can you do it without losing velocity?

The only really impressive 4 valve V8 engines I've seen were all forced induction.

 

i know it was dohc but what about the lt-5 that motor was seriously detuned

 

I just returned from my local Chevy dealer looking at exhaust clearance issues. The stock manifolds seem to clear Z28 bodies by 1.5 inches, the closest part being the steering joint. If there is any closer object that I should know about please let me know.

Here are some issues I am dealing with that I would appriciate your input on.

1. Using the stock exhaust or standard headers on a 4-valve, canted or hemi will probably be nearly impossible. The main reason is that the exhaust face of the head on the 4-valve and hemi heads has to be nearly square to the deck so that means facing 45 degrees down in the car. Also it is moved out about 1/2 inch (at least) Let me know if you can live with buying the special header or if this is a deal breaker.

2. If I do a four valve with a price target in the 3K range, it would have to be a push-rod set-up like the arao someone here mentioned. For a DOHC, I think the cost of the parts and room for all the front of the engine stuff that would have to be moved forward on spacers would be a bigger headache than most people are willing to go for, let me know if I'm wrong about that.

3. Some of you seem interested in the hemi design, at least partly for the spark plug issue. After looking the cars in the dealer today, I can see why, the engine is nearly under the windshield. If I made a hemi, it would be possible to use the same intake and a slight possibilty of the exhaust. A modern hemi would have a twisted intake and exhaust valve similar to the 429 Ford (SCJ) or even better example the Ilmor pushrod Indy engine from about 1994.

If the pushrod twisted hemi would a better fit for cost and practicality reasons, maybe that would be the way to go. Please let me know your thoughts on this type of head as compared to a pushrod 4-valve.

 

Here's something to think about:

If you can produce a cast aluminum head for under 3 grand, you should consider making a cast manifold for a C5R head with a clone head instead. If someone would cast a intake for a C5R I think more people would use them. The C5R head will accept stock headers and will make a ton more HP than a conventional gen 3 head.

 

1.--I really do not think special headers will be a problem for most people. Especially if they are @$600 like you said earlier. The FLP Long tubes and Y-pipe set is about $1,200.

2.--I agree. I was just wanting clarification. The pushrod route with split rockers like AERO will be much easier than a full DOHC swap. Let's see the pushrod version.

3.--I also like the Hemi head idea, but I like the 4-valve idea better. The complex angles for a canted valve hemi head I wonder about. With a 4-valve head it would seem you would be able to have similar power and torque with a lower lift cam, and therefore lighter valve springs. This is a toss up. I would buy either one if I had the $$$$, and they met the previoiulsy noted requirements-----stronger thicker deck, more power than current ported heads, etc. I'd like to see a larger chamber for forced induction cars also----maybe equilavent to a 9.0:1 CR.

 

I you make a C5R head and intake, regular headers will bolt right up

 

hemi ......mmmmmmmmm
which ever you can pull off for under 3k and if you blow the hp doors off the current ported ones then i would buy either one... hemi or 4 valve...

 

John, I think Todd (Reckless) has a good point. If you want to be the guy that offered something to the LSx community and made a killing, then cast off the C5R heads and intake. If however you are wanting to be more of an elitist, and have a knack for the obscure, by all means build the 4v. Either will sell. If ask long enough, you find just as many ppl will offer to buy then back out, and those never interested will all of a sudden buy. The market is here, the demand for more flow, and mostly more reliablity (thicker decks) is something you can count on. And with the addition of the LS engines in GTO/Caddys you just got more demand. We all know how Caddy owners are...talk about elite! Not much else to offer you. I dont have C5R heads or I would send them to you. Thanks.

Charlie

 

Can someone point me to a good photo of a C5R head and maybe point out some of the differences between that and some of the other heads?

Are they much different than a 6.0L #317 casting?

I see pairs of C5 heads selling on Ebay for $150, they don't seem to be very valuable. maybe the R is a big difference?

 

I have to disagree with you Todd. C5R heads with their enormous ports and tiny combustion chambers will not be good for the vast majority of people which have an engine under 400 inches and need to use pump gas.

schmidtmotorworks
Yes the C5R heads are way different than the 6.0L heads. The C5R heads are a special casting that GM made for the Corvette Race Car. Huge intake and exhaust ports, tiny combustion chambers (13:1+ compression ratio), and require a custom intake.
I still say that a well designed 4 valve head could out flow the current ported LS1/6 heads and maybe equal an as-cast C5R head with better charge velocity (TORQUE) from the smaller port volume.

Just my thoughts gang.

 

Here is some information that I got from the almighty Google:

These are the same heads that propelled the C5R Corvettes to a LeMans 24 hour win. The are for maximum effort Gen 3 racing engines, which should incorporate the use of a Gen 3 racing block P/N 12480030, also. A special manifold must be fabricated to use this head. The cylinder heads include the following features:
The basic height, width and attachment faces are in stock location to dowel and deck position. All dimensions and fasteners are metric.

The basic valve angle was revised from 15 to 11 degrees to produce a smaller chamber . The valve angle also provides more space for aftermarket shaft mounted rocker arms.

The rocker cover hold down bosses are incorporated into the rocker arm plateau for the 4-bolt center hold down type cover (1999 model year).

The chamber volume for the P/N 12480005 head is 38cc with flat faced valves of. 75mm inlet and 1.5mm exhaust margins.

The P/N 12480090 provides additional material for CNC porting and chamber shaping and starts at a volume of less than 30cc's.

The inlet port roof and floor is raised and the attachment pattern is designed for a Kinsler type fuel injection manifold. Inlet port is 57.15 x 36.58mm / 55.957mm dia. precision finished.

The cylinder head is machined for larger diameter springs (41.5mm or 1.63" dia. machined pocket).

The exhaust flange is identical with the production part.

The exhaust port is stock size.

The head is machined for a 12.712 / 12.688mm dia. valve guide bore.

Rocker cover oil rail seal is a reverse tapered groove for a 3.2mm dia. (.125") free length "O" Ring.