What would you pay for a dohc 4 valve head

[WingZr0]

Granted I may be off on the terminology per chance,

but ain't what you're talking about a variation of the Z432 head Jimmy?

[e_racer1999]

^the head from the S20 doesn't work for an l-series block. he's referring to either the OS Giken head or the custom head that 1 fast Z built. i'm assuming it's the 1 fast Z head, because i think there might be some interest in building more....?

[m4xwellmurd3r]

not really. the Z432 had the S20 engine from the GT-R of the time. so it was an engine swap, and not a bolt on.

however, Nissan did have a racing head for the L series that was a twin cam if i remember correctly

Having a twin cam on my car would really be awesome. I wonder what sort of a difference in power it would be from stock, to direct bolt on of the new head...

and seeing 1 fast z's head on that car, and watch it fire up. that's engineering ingenuity right there. everyone was saying "oh that won't work blah blah blah" he did it anyways. I can't wait to see the driving videos

[JimmyZ]

A variation but most importantly a single piece new casting. I'm just debating whether to try an N/A version first or go straight to forced induction. It would be easier to make a non N/A head as far as port design goes.

Since the person buying it would obviously want to install valves/seats/cams suited to their needs it makes sense to leave those things out.

[Jeff G 78]

Since the person buying it would obviously want to install valves/seats/cams suited to their needs it makes sense to leave those things out.

Yes and no. If they were off the shelf items, then yes the buyers might want to get them on their own, but a unique DOHC head would require cams that are designed for the specific engine and head layout. 1FastZ bought custom built cams. I'm sure those weren't cheap. Either the head would have to be designed to use some other manufacturer's valvetrain parts (i.e. Toyots Supra valvetrain), or the person making the heads would also need to supply everything required and build enough spares to have stock for years to come. :cross-eye

[WingZr0]

Thyanx all for the lesson

I say go with the easiest first Jimmy and build the NA version then

build the Force induction 2nd if that makes since.

It sounds like it would be quicker to make the NA if you don't have to make the valves and stuff also.

Forced Induction sounds like theres tons of possiblities you can

opt out for that one though for all kinds of combinations and HP

Just my thoughts ~Z~

[Carl Beck]

Carl, the rotary valve system looks VERY interesting. Are they building one for the L series?

Hi Mike:

No - but since they seem to have built a head for the M/B in-line six - the head for the "L" series can't to too much different in terms of the total design effort.

I have no idea what they would charge - but if they were to produce say 10 or more of them - it might help them get more publicity.... It certainly seems that the design is past the experimental stages, but still not broadly applied, nor fully proven by time and use...

Having the cams "be" the valves (so to speak) and getting rid of the entire conventional valve train seems like a great idea to me...

FWIW,

Carl B.

[JimmyZ]

Such a head would have better VE for sure. Tweaking it though...

I'd like to find out what the secret is to making a good seal on the "valve" face of such a head though. What about carbon on the exhaust side? Grinding a new seat/socket looks to be more like replacing the head. (Or at least sending to manufacturer for remachining.

It is extremely cool though.

[XjakobX]

Heh, JimmyZ, I'm a home caster/machinist too. I've actually poured cylinder heads before, but a scale model of the L24 isn't quite the same...By the way, a 1/8 scale model of the stock L24 produces ~4.6HP, pretty good, I think. Next time i get to see that engine again, i'll take some pictures for you guys! (it's in a modeling museum about 20Hrs away from me...)

As to doing it lost foam, you'd get much better results that way. The best method to make the patterns is CNC, but you'd have to make the patterns layer-cake style. (not that that's a real problem.) the only worry that i would have would be getting the internal passages packed with sand fully, an internal blockage would be killer.

[WingZr0]

Heh fellas, I don't know if this is of any help for ya,

http://www.datrats.com.au/OS%20GIKEN%20ENGINES.htm

[NZeder]

N/A all the way baby

One question why doesn't someone make a roller rocker kit for the L6 series? Hell you an get roller rocker kit for just about every thing else and sorely there would be enough interest from us to have a smoother valve train?

[John Coffey]

Think five figures for Brian's DOHC cylinder head (complete) if he ever decides to do a production run. LY crossflow two valve heads are around $20K+ right now if you can find one.