Stock head capability

[addicted4life]

To start, yes I've searched and googled but all I find is what the engines max threshold is.

What are the stock heads good to on my car? 1993 300zx TT 5speed JDM, yes from Japan not an imported motor. I'm doing a rather large build that is about to get started again and I'm trying to decide on holding off on the headwork for now till next year or not. Will I float valves and what power & boost level will I see issues?
Heads are the one thing I really do not know much about. Even just to sumerize or go I depth on them would help. Or link me to info because I can't find anything.


Thanks NICO

[NolimitZ32]

Valve float results from spinning the engine too fast as in way above the factory redline, it happens due to insufficient recoil of the valve springs and has basically nothing to do with "HOW MUCH POWER" The two components which should be understood to be kept separate are the valvetrain (valves, springs, cams, lifters) and the casting itself (responsible for flow limits) from my research I'd say a set of heads in stock form should be good for 800-900. Be weary this is just an estimate I make from all the info that's collected in my head about VG30DE/DETT. There are programs that you can download that will actually do calculations for you based on parameters that you enter, maybe check out one of those (desktop dyno).

[addicted4life]

Well I'm going for 850whp, or no more then 24psi on race and meth, so it's right there then isn't it? I'm just worried about issues regarding flow and the springs not holding up. Like I said I don't know too much about the heads

I'm not saying I'm not going to do them, just wanted to know if ill run into issues with them if I wait for another couple months is all

[NolimitZ32]

You should be able to pull that kind of power out of the car without touching the heads but you would do well to build the top end if you're going for those numbers because it'll be that much easier and you will already be setup to spin that mill higher, there's lots of hiding up there and if you can make the engine stable at higher revs you can find some of that hidden power.

[addicted4life]

Ok thanks for your insight buddy

[Ziggy1621]

Of course you will need head studs, and I would give them a good refresh with new springs and lifters at least.

[addicted4life]

Yea I ended up getting a really good price on a ARP head & main stud kit so I got the whole shabang. Depending On how the income tax goes will depend on what I do with my heads, otherwise it will be another's month before I can buy all the head parts and afford the headwork without shorting myself for the rest of the build. It's on my list though!

[Ziggy1621]

I see you are going big with it, what are your plans for the ECU, have you checked into Haltech?

[addicted4life]

Go look at my first post in my build thread buddy
I updated it to my current build design. All parts listed I have already bought and paid for. Its pretty detailed.

[Ziggy1621]

[NolimitZ32]

Did you get the ARP 2000s or the L19s, with your goals you'll want the L19s for an extra safety margin and peace of mind.

[addicted4life]

Couldn't find the L19s ANYWHERE, I'm not going past 24-25psi anyways and that will be rare I run that high of boost. Tuning it to 25 but running between 12-18 a a regular basis.

[NolimitZ32]

IPP sells L19s, with 850whp (~1000chp) I would strongly reconsider, have a chat with Kyle from IPP and Greg at SZ. Would hate for the head to lift after all that time and money.

[addicted4life]

It was sounding them. Everywhere was back ordered. When I head to California in the fall with the car I'm going to get a couple more things and they are on the list. Trying to get it going now, didn't want to wait 2 months before they could even ship