427

iTrader: (3)

Everybody has an opinion, so here's mine.
If you want a high torque low buck gen 3 on pump gas use a ported stock head.
If you want to impress your friends with high rpm ability with high cost, then 4 valve is for you.
If you want a high torque high hp package use the C5R.
C5R intake port is very high velocity mid sized port in a raised port design. The valve angle is shallow which keeps the chamber volume in a racy 44-50cc area. The port location dictates offset rockerarms on both intake and ex.
If you produced a stable deck version with a matching intake you would have my attention.
Kurt

1CAMWNDR

iTrader: (21)

Let me see if I can attach the only picture I have of a C5R head so far........

1CAMWNDR

iTrader: (21)

Kurt, do you think a C5R type head would be of any benefit for a street/strip 346-400 inch motor? I thought they would be needed only for 409 and up.
Thanks.

racetolive

a 4v wedge style head with the sparkpulg in the center of the combustion chamber would be more pratical than a hemi style chamber even the new hemi is ot a true hemi it is for all for all purpose a wedge head with the valves laid out like a hemi in other words it would not pass smog and be hard to build high compression with out domed pistons killing the flame front

Nickn20

well can you produce a cylinder head that can flow more than what we have today? IE 300+ cfm intake, LS6 heads 320-330.

schmidtmotorworks

Thanks for the post of the C5R, the ports seem more like what I would expext for a racing engine. I think from what I am reading here, a stronger head with canted valves, an intake port similar in form but smaller in cross-section would be the best fit. Of course a new manifold would be needed but it sounds like that is needed anyhow.
I think a standard exhauste would still fit.

So, I think we are closing in on a configuration, any problems we are overlooking here?

schmidtmotorworks

BTW What is the favored header?

427

iTrader: (3)

The smallest bore I have ever used with a C5R valve spacing is 4 inch. With that limitation said, The C5R would be better in any racing application for power production. The ability to move air is not dictated by cubic inch alone. If there is no rpm limit on the class of racing you like and you can fit the head in your budget, I would use the R head everytime.
Kurt

Reckless

iTrader: (9)

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.

CAT3

iTrader: (9)

Todd, or Kurt. How would the C5R heads and intake perform with say a TT 346? Would the turbos make good use of the extra flow, or would it be a moot point since its being forced?

1CAMWNDR

iTrader: (21)

Yeah, Kurt deffinatley knows his ****.
Yes, now this is true, if he is only looking to build a race head by all means build a C5R type head. I got the impression he wanted to do a street performance head which is why I didn't think it was a good idea.

427

iTrader: (3)

To use the head you need a 4 inch bore or larger. This is for the ex valve to clear the cylinderwall.
The head would be perfect for a TT if you could run the larger bore.
Anytime you increase flow you lower boost for a given cfm. That will lower inlet temp at equal flow rates. Your ex backpressure should also drop. These are all good things, especialy when you crank the boost back up!
I have a TT C5R engine that is ready to be assembled that is for sale, but the price would scare most people(including me).
Kurt

CAT3

iTrader: (9)

Kurt, thanks for the clarification. I wasnt sure why it needed a 4" bore, if it was more for not having the port velocity stall or valves hitting or what.
I am getting things ready to have a Custom TT kit built for my car. Builder wants to use stock cube based engine so if anyone else wants they will have production numbers to go from. Thought maybe when its done, go large bore and use some High Flow heads...oh how the search for power continues.

Charlie

Kurt if you dont mind, can you pm me the investment for your setup?

66ImpalaLT1

Honestly, I wouldnt do anything until the 3 valve LS7's hit the street. If you build a high $$$ head that performs well, and GM comes out with a head that knocks its socks off you wont be able to recover your R&D investment.

Reckless

iTrader: (9)

Then again, folks are still selling small block Chevy heads in mass quantities. Making money is about accepting risks

1CAMWNDR

iTrader: (21)

That is the damn truth.

Dueledaily

Dont most 4 valve per cylinder cars have more than one cam? Sounds like a nightmare too me.

1CAMWNDR

iTrader: (21)

Yes, Dueledaily, most 4 cam motors have dual overhead cams. What we are thinking on here is still a single cam in the block with pushrods that actuates a forked rocker. 1 pushrod would open 2 valves. I really do love this idea!

jaberwaki

ok.....
sounds like enough info...

lets see a prototype!!!

66ImpalaLT1

Yes well I guess it depends on whether the LS7 heads fit the Gen-3 blocks and how good they are. Its all a risk.