How much can a stock 1g head take?

[GeneralChaos]

im sure this has been covered but I really cant find it.


Im wondering if I took a 1g head and rebuilt it with fresh oem parts, and did a mild port/polish to it, how much hp should it be able to take without crapping out on me?

 

[92redman]

What do you mean how much could it take with out crapping out? The head can take all you throw at it. As long as the valves seat all the way around and the guides aren't worn badly you won't have problems. If you run high boost, a good set of head studs will save your head gasket, having good springs if you go with high lift cams will reduce the risk of valve float(the stockers are pretty good though).

Things to know when rebuilding a head:
-P&P can result in less flow if not done properly.
-If the valve guides are worn, they should be replaced
-Your valves must seat all the way around or you WILL burn them
-Having a flush seal surface will prevent leaks and blown head gaskets
-Cam bearing caps must go back exactly where the where and facing the same direction when they cam out
-A valvespring compressor is a must
-Might as well throw in some 3g lifters while you are in there

Now how much power can you make? As far as I know, there are no aftermarket heads, people have made 700+ HP using a stock head. Obviously the components aren't stock but you get the idea.

 

[GeneralChaos]

Obviously the components aren't stock but you get the idea

sorry if I didnt explain well but thats kinda what I meant. If im making about 500ish hp, will a rebuilt head with stock oem components be able to handle that? or and I going to have to go get the aftermarket springs/retainers/ and the what-not.

 

[92redman]

You don't "need" anything. If you are planing to rev the engine past 8000 rpms and have high lift cams, it would behoove you to use valvesprings with more seat pressure. If you are making that much power, you probably are going to upgrade your cams, so I would say you should get valvesprings.

I've seen different revlimits quoted with the stockers, usually between 8000 and 8500 RPMs with a mild cam. If you are using a turbo big enough to get you to 500 ponies, you are going to need to rev your engine out a ways past stock limit inorder to reap the benefits of such a beast.

You can pick up a set of valvesprings and retainers for about $260 from crower or just the springs from HKS for around $210.

 

[GeneralChaos]

yea I was going to put some hks 264's in I think (some thread had hp gains from all kinds and the 264/264 combo worked the best, but that could only be on stock i dunno) and I want it to be streetable and gotta look into the ride on 272's.

So I should buy some hks springs and retainers?

 

[92redman]

I am not going to tell you what you should get. But on the engine I am building I am going with crower valvesprings and retainers just because they are cheaper than HKS and I don't really think the HKS will give me anything over the Crower. The HKS seamed cheaper at first, but then I realized that is only the springs, the retainers are another 1xx more. I guess though, if you wanna spend the money, keeping HKS w/ HKS would probably be better since they would manufacture the springs to work specifically for their cams. I am not going with HKS cams though, so that is another reason why I am not going to use their springs.

There is a lot of info out there, you just gotta know how to search for it. Do a search for "hks valvesprings" or just "valvesprings" and decide for yourself if you need them or not. You can also go to member search and search people's engine upgrades to see who uses hks or webcam or crower or whatever you want and then PM those people to see what they have to say.

 

[ITSME4G63]

Ive read that shepherd ran 10's on stock springs, so why bother?

 

[Groomz]

Originally posted by ITSME4G63
Ive read that shepherd ran 10's on stock springs, so why bother?

That is a good point, but shep is the exception, not the rule.

Just remove any cast flashing on the head and have a the seats redone and a stock 3 angle valve job also. The 1G head is very advanced ( compared to SBC or Ford OHV heads ) and can flow a significant amount, even past 8000rpm's. Lots of bench racers and Muscle car guys get dissapointed when they aren't offered custom heads for our cars.

Just to let you know, 2G heads suck. Stay away from them.

-Groomz

 

[92redman]

Oh, haha, I didn't even notice he has a 2g. Get a 1g head

 

[Groomz]

You could probably pick up a good 20hp between 5000-7000rpm's. The more boost you run, the more power you can get over the stock 2G heads. One more thing about shep, he only has to make his parts last around 9 seconds, while ours have to go around 150,000miles. Yeah yeah yeah, his car is street legal. I bet he has a beater.

 

[GeneralChaos]

Yea I was going to use a 1g head, from my understanding pretty much everything 1g is better except the pistons.

thanks for making sure though.

 

[KFT0001]

Originally posted by GeneralChaos
Im wondering if I took a 1g head and rebuilt it with fresh oem parts, and did a mild port/polish to it, how much hp should it be able to take without crapping out on me?

Something else will go before you ever break the head from increased power. If you detonate or over rev then that's another matter. More power doesn't cause you to need stiffer springs, lighter valves, etc. - it's just higher rpms.

 

[GeneralChaos]

so all the head "internals" like the springs ect only make it so you can rev the engine higher (increase the redline?) and make more hp that way?

 

[92redman]

You won't make more HP by simply reving higher. You will benefit from increasing your redline if you have a large turbo that still makes good power well beyond your stock redline. The reason you need stiffer springs is because with larger lift cams at higher revs, your valves are going to be moving so fast they won't have time to seat all the way causing you to loose power and/or make contact with the pistons. Increasing seat pressure will pull the valves up with more force making sure they close completely.

So with that in mind, if you don't plan to rev past your stock rev limit, you can still use your stock springs even with upgraded cams.

 

[sakrafice]

Andy are you doubting me ? if I say u should get 1g head, vavles and just sleeve them ... then do it, im not going to steer you wrong man. I told you thats the more cheaper less hassel way to do it anyway.

 

[GeneralChaos]

Originally posted by sakrafice
Andy are you doubting me ? if I say u should get 1g head, vavles and just sleeve them ... then do it, im not going to steer you wrong man. I told you thats the more cheaper less hassel way to do it anyway.

I never doubted you im just having to decide if I want to do the fast, but cheaper way of things, or if i want to drop the cash for the "STREET BEAST D00000D!" effect.

Besides I cant completely jock your whole setup and if I go the cheap route thats almost unavoidable (1g rods, 2g piston ect) so its kinda up to you to because I told you i wouldnt jock it all.

 

[cait sith]

Originally posted by Groomz

Just to let you know, 2G heads suck. Stay away from them

Uh. No. Just no.

BTW: A stock 2G head is more than enough to run 11's, even on a smogged California car.

 

[sakrafice]

I watched somethin on speed world about the 1g head and 2g head, and they tryed both on the track and the time didnt change but like a fraction of a second. as in they took the head off and put 1g on ran it, then swaped it to the 2g and ran it.

 

[Groomz]

Originally posted by cait sith
Uh. No. Just no.

BTW: A stock 2G head is more than enough to run 11's, even on a smogged California car.

So there's no performance advantage to a head that flows more?

Better change the vfaq:
http://www.vfaq.com/mods/1G-2G_intake.html

The intake manifold tells a different story also: