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Alright, so if I were only going to do intake or exhaust then which one would be better and why? Also what makes a good aftermarket valve?


Thanks
Coop

Why would you only replace one if you're taking your heads off?

Maybe I don't understand. Are you talking about rebuilding your heads and re-using the old stuff? Or upgrading to oversize valves?

Either way, it's not worth doing it unless you do them both. These heads don't have a severe restriction in one and not the other.

Yes I've had plenty of different heads rebuilt, machine shops always re-use old valves except recent Jeep head 1 was damaged and they just replaced 1 with new.

3/S heads are very efficient stock, can improve when you're talking 700HP+ car but..

[quote=""JagdStealth""]Why would you only replace one if you're taking your heads off?

Maybe I don't understand. Are you talking about rebuilding your heads and re-using the old stuff? Or upgrading to oversize valves?

Either way, it's not worth doing it unless you do them both. These heads don't have a severe restriction in one and not the other.[/quote]

Well the heads have to come back off my car, they are going to get ported. Figured I might want to do some valve stuff but was curious about all of it.


Coop

Okay, a simple rebuild...just replace them all with stock valves and port everything else.

Only way you'd ever want to do one set and not the other is if there was a restriction in the design of the head or something along those lines.

anyone ever just do intake or exhaust. I know when you try to max the valves out then one size has to be bigger then the other. Which one would you make bigger and why. Also again what makes a good valve.


Coop

i would do both if i were going that far but IF i were to do just one side for a forced induction car i would work more on the exhaust side. you have pressure forcing air into the intake side but just the piston pushing the air out the exhaust so thats the side i would try to make more free flowing.

Coop - I'm still baffled as to why YOU would do this. Well, actually, you've done everything on the cheapest budget so far so maybe I'm not so suprised. But really, pony up the dough and do both sides man. $13 valves right?

Scotty

[quote=""GTO Assassin""]you've done everything on the cheapest budget so far so maybe I'm not so suprised. [/quote]

scotty if you think this is true you need to read through my mod list again. In fact if I would of gone cheapest I could of then I wouldnt of even got my motor rebuilt. Sorry if I dont have your budget that you have spent on your build.


Coop

Dude, you are misunderstanding cheapest for tight arse. I never said you were a tight arse. I said you took the cheapest rout for your build. If I'm wrong, tell me. I wasn't taking a shot at you champ, just stating that when you buy most of your parts from 3si, trying to save money where you can, then eventually, there's a chance something may fail. I think there are somethings you should spend the money on, and there are others you don't have to. Ya dig?

Scotty

[quote=""GTO Assassin""]Dude, you are misunderstanding cheapest for tight arse. I never said you were a tight arse. I said you took the cheapest rout for your build. If I'm wrong, tell me. I wasn't taking a shot at you champ, just stating that when you buy most of your parts from 3si, trying to save money where you can, then eventually, there's a chance something may fail. I think there are somethings you should spend the money on, and there are others you don't have to. Ya dig?

Scotty[/quote]

There were alot of things I could do cheaper in my build and didnt man. I am sorry you cant even look at my mods and tell that. Were they bought off of 3si, yeah most of them were bought off of 3si but there were alot of diff ways I could of gone that would of been alot cheaper.


Coop

Ok.

I just bought 24 oversized 1mm valves.


Coop

*cough*adapter plates*cough*

[quote=""moffman93'""]*cough*adapter plates*cough* [/quote]

im going to see if I like them first. Its easy to swap out headers. But alot of down time and pain to swap out valves later. Get my drift? It would be like trying to buy rods later so I could of bought headers now.


Coop

I hear ya man. Do the internal shit right the first time, nothing worse than looking to upgrade(bigger turbos) and then having to upgrade internals, gets time consuming and most importantly, expensive.

yup and trust me, with nitrous i will have no problem making whatever HP i want.


Coop

[quote=""vr4""]i would do both if i were going that far but IF i were to do just one side for a forced induction car i would work more on the exhaust side. you have pressure forcing air into the intake side but just the piston pushing the air out the exhaust so thats the side i would try to make more free flowing.[/quote]

You have a hell of a lot MORE pressure pushing the exhaust gases out than you will ever have pushing the intake charge into the cylinder It makes more sense to go with larger intake valves if you're only doing 1 side.

[quote=""Wolf_Zero""]You have a hell of a lot MORE pressure pushing the exhaust gases out than you will ever have pushing the intake charge into the cylinder It makes more sense to go with larger intake valves if you're only doing 1 side.[/quote]


you also have the turbine housing restricting flow and backpressure in the exhaust manifold due to the turbine and x amount of boost.


forced induction cars overcome intake rectrictions much easier than exhaust restrictions. from now on ill save anything technical for 3stech. see ya there

[quote=""vr4""]you also have the turbine housing restricting flow and backpressure in the exhaust manifold due to the turbine and x amount of boost.


forced induction cars overcome intake rectrictions much easier than exhaust restrictions. from now on ill save anything technical for 3stech. see ya there [/quote]

rofl.