2g head on a 1g block

[5150]

Will this setup work efficently or should i go with a 1g head as well. This setup is what im going to run on my race motor im building on the side so just about anything you can think of that could be done to this motor probably will be. I just need some info on as far as wich head to run fully built. I've heard that the 2g head is better when its built but the 1g head is better stock to stock.

 

[dedlewamp]

I would run a 1G intake manifold and head and a 2G exhaust manifold. The 1G head has larger ports than the 2G. Check out the VFAQ for some pictures if you are interested in the differences.

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

 

[Talesin]

There has been a lot of discussion about which setup to use; some insist that the 2G head has a better dispersion pattern.

Personally, I lean toward the 1G head. The passages are larger and thereby can handle more volume.

Whatever you decide, just make sure your intake manifold runners and head intake ports are matched, or the turbulence produced will cause problems; whether that means using a 2G head and porting the intake side to match the 1G intake manifold, using a complete 1G head and manifold set, or a complete 2G head and manifold.

2G exhaust manifold (or the SBR cast exhaust manifold) is a given though, if you aren't going tubular... 1G manifolds were much more prone to cracking.

 

[Verticaljump1]

Volume doesn't make an good flowing head, velocity does. I'd go with the 2G head, and have it ported to exactly what you want. A 2G head is better off the bat only because you have so much casting to remove the way you want it removed. Make sure you get it fitted for the larger 1g headstuds, and use the right CAS.

 

[wishihadatalon]

Volume doesn't make an good flowing head, velocity does. I'd go with the 2G head, and have it ported to exactly what you want. A 2G head is better off the bat only because you have so much casting to remove the way you want it removed. Make sure you get it fitted for the larger 1g headstuds, and use the right CAS.

Its important to know that you should never port down on a 2g head. The 2g head will make more tq and awesome hp. It doesn't choke out till around 600whp. The only thing the 1g head has on the 2g for a street car is better cams and intake manifold.

 

[gsxtacy]

2g Head > 1g Head

Velocity.....

Anyone seen a Evo8 Intake port?

Seems Mitsubishi knows something everyone else doesn't.

 

[OnMyWayTo12Secs]

I currently run the setup of a 6bolt block and a 2g head, AND LOVE IT. You cannot tell the difference between the two, and if your that worried about it, the 2g head has more meat to be ported on it. The only thing to remember is, a 2g head needs the head bold holes reemed out by 1mm in order to fit 6 bolt head studs. This combo with ARPs forged internals and a stock 2g head has made me very happy. A lot of people on here are will disagree with me, but that's okay too! 2g Heads are where its at!

 

[gijoe985]

I currently run the setup of a 6bolt block and a 2g head, AND LOVE IT. You cannont tell the difference between the two, and if your that worried about it, the 2g head has more meat to be ported on it. The only thing to remember is, a 2g head needs the head bold holes reemed out by 1mm in order to fit 6 bolt head studs. This combo with ARPs forged internals and a stock 2g head has made me very happy. Alot of people on here are will disagree with me, but thats okay too! 2g Heads are where its at!

Is this all that is needed to put a 2g head on a 6 bolt short block?

 

[cruisintalonawd]

yep thats all I did it too I just threw the 1g intake mani on it, I need to get the 2g mani back

 

[90laserRSfwd]

what turbo are you using and how much power are you trying to make, pre 600 hp I'd be looking for an efficiently flowing set up not one that has the highest velocity. Although they go some what hand in hand

 

[BOOSTIN21]

^^velocity equals efficient flow. no other way of looking at this. there are great write ups on this already. the large ports dont mean dick which was covered. 1g head only flows more because the 1g cars came with more agressive cams and a larger throttle body. Better cams and larger throttle body on a 2g head with proper porting will outflow a 1G head with porting due to better port angle on the valve. The grosly oversized port on a 1G head only slows velocity and creates a huge angled entry around the valve. The basics of head porting state this is a poor design, much the reason why it was updated and changed on the 2G head. The whole point of using a 2g head is the angle of the air's entry into the valve is so much better. A 2g smim matches the port of a 2G manifold so a nice angled port job to straighten the path of the air down on the valve will work better. Simply having a big entry to the valve does not flow more air than a properly designed port (1g vs 2g).
I will be building my next motor soon, and its a 6 bolt and 2g head but i will spend more time properly setting up the head then i will the bottom end much due to correct porting.

I saw someone on here used a 1g intake manifold, thats a no no. Ports dont match up, but a great alternative to this and stock look is a tough find. An EVO III intake manifold is perfect fit to the 2g head, but good luck finding one. You would be better off extrude honing a 2g intake manifold or 2g SMIM.

Hope this helps.

 

[gob4sho89]

I am doing a 6bolt swap and keeping my 2g head... In 2003 I was in europe (Sweeden), and went to a dyno day at a shop next to our hotell. I watched a 97gsx make over 680hp with a 2g head. I was 14 at the time and wrote down in my notebook(trip diary) that he had only polished the ports and was using hks 272 cams... along with a fully built shortblock and a huge turbo. I really wish I would have written down his name. That Eclipse was the reason I bought a dsm. Another reason that I am keeping the 2g head is that I am running out of money for my build and cant afford another head and intake mani. BTW, what is a SMIM?

 

[Ginglingston11]

I am doing a 6bolt swap and keeping my 2g head... In 2003 I was in europe (Sweeden), and went to a dyno day at a shop next to our hotell. I watched a 97gsx make over 680hp with a 2g head. I was 14 at the time and wrote down in my notebook(trip diary) that he had only polished the ports and was using hks 272 cams... along with a fully built shortblock and a huge turbo. I really wish I would have written down his name. That Eclipse was the reason I bought a dsm. Another reason that I am keeping the 2g head is that I am running out of money for my build and cant afford another head and intake mani. BTW, what is a SMIM?

sheet metal intake manifold

 

[gijoe985]

^^velocity equals efficient flow. no other way of looking at this. there are great write ups on this already. the large ports dont mean dick which was covered. 1g head only flows more because the 1g cars came with more agressive cams and a larger throttle body. Better cams and larger throttle body on a 2g head with proper porting will outflow a 1G head with porting due to better port angle on the valve. The grosly oversized port on a 1G head only slows velocity and creates a huge angled entry around the valve. The basics of head porting state this is a poor design, much the reason why it was updated and changed on the 2G head. The whole point of using a 2g head is the angle of the air's entry into the valve is so much better. A 2g smim matches the port of a 2G manifold so a nice angled port job to straighten the path of the air down on the valve will work better. Simply having a big entry to the valve does not flow more air than a properly designed port (1g vs 2g).
I will be building my next motor soon, and its a 6 bolt and 2g head but i will spend more time properly setting up the head then i will the bottom end much due to correct porting.

I saw someone on here used a 1g intake manifold, thats a no no. Ports dont match up, but a great alternative to this and stock look is a tough find. An EVO III intake manifold is perfect fit to the 2g head, but good luck finding one. You would be better off extrude honing a 2g intake manifold or 2g SMIM.

Hope this helps.

Yes, it does help. Now, what about throttle body? 1g or 2g? I am going to have to look up extrude honing. That's something I've been reading about a lot lately, but nothing with great detail. I guess, like in the 4v 351c I own, the giant ports of the 1g would be opportune if you were running insanely high rpms.

 

[gob4sho89]

Thanks for clearing that up...

 

[BOOSTIN21]

gijoe... actually a lot of high HP cars use 2g heads, its very similar to an EVO head. its what i will be using when i build my next motor.
as far as TB's between 1g and 2g is a 1g. but N/A 1g TB is actually a plus a lot of people use those. will try to dig up some info i have been saving. i believe that the 1g TB is naturally bigger 60mm and can be bored to 64mm, i dont remember what the 2g TB is factory. but i know plenty of 2g guys switching to a 1g TB. extrude honing can be done by JMFabrication i believe, its not cheap but when you look at intake manifold comparisons, a 1g Intake is as good down low and mid torque if not better than most SMIM's. Add some huge cams and bored TB, that should make up for lack of top end along with honing. You have a very nice setup. This is the way i see it. i did a lot of research on it and this is what i gathered.
cullen

 

[blcknspo0ln]

The 1G nonturbo and turbo TB's are the same at 60mm versus the 2g one which is 52mm. The difference between a nonturbo 1G TB and a turbo 1G TB is that the nonturbo TB has a lip in which you can put a coupler on it and the turbo TB needs a traditional TB elbow.

 

[dsm-onster]

It is absolutely comical that all those who post and boast the 2g head being better all say you have to port it. Is it a bolt-on upgrade to the 1g block? Not at ALL!!!! Not one soul has proven it is.

 

[DSMunknown]

It is absolutely comical that all those who post and boast the 2g head being better all say you have to port it. Is it a bolt-on upgrade to the 1g block? Not at ALL!!!! Not one soul has proven it is.

I wouldn't say that. I'm against porting wherever and whenever I can get away with it. Seriously. But I have my own opinions and thoughts on this (regarding the use of a 2G head on a 1G block). But it's too early in the morning and I need to go to bed.

 

[wishihadatalon]

It is absolutely comical that all those who post and boast the 2g head being better all say you have to port it. Is it a bolt-on upgrade to the 1g block? Not at ALL!!!! Not one soul has proven it is.

I never mentioned porting. You don't need to because the head can already support the hp that most of us will get. Look at a 1g head and then a 2g head. Look down the runner. The 1g head makes a very serious bend right before the valve, and the 2g head has a much straighter shot.

 

[wishihadatalon]

^^velocity equals efficient flow. no other way of looking at this. there are great write ups on this already. the large ports dont mean dick which was covered. 1g head only flows more because the 1g cars came with more agressive cams and a larger throttle body. Better cams and larger throttle body on a 2g head with proper porting will outflow a 1G head with porting due to better port angle on the valve. The grosly oversized port on a 1G head only slows velocity and creates a huge angled entry around the valve. The basics of head porting state this is a poor design, much the reason why it was updated and changed on the 2G head. The whole point of using a 2g head is the angle of the air's entry into the valve is so much better. A 2g smim matches the port of a 2G manifold so a nice angled port job to straighten the path of the air down on the valve will work better. Simply having a big entry to the valve does not flow more air than a properly designed port (1g vs 2g).
I will be building my next motor soon, and its a 6 bolt and 2g head but i will spend more time properly setting up the head then i will the bottom end much due to correct porting.

I saw someone on here used a 1g intake manifold, thats a no no. Ports dont match up, but a great alternative to this and stock look is a tough find. An EVO III intake manifold is perfect fit to the 2g head, but good luck finding one. You would be better off extrude honing a 2g intake manifold or 2g SMIM.

Hope this helps.

I just bought an EVO 3 intake manifold for my girlfriends 2g. I am really really hoping that it is one of those things that goes into the right combination of parts folder I got it dirt cheap and I couldn't pass it up.

 

[dsm-onster]

I never mentioned porting. You don't need to because the head can already support the hp that most of us will get. Look at a 1g head and then a 2g head. Look down the runner. The 1g head makes a very serious bend right before the valve, and the 2g head has a much straighter shot.

A stock port 2g head w/ the same cams as stock port 1g head does not perform better at power levels most of us will be satisfied with.

. . . Now getting a used 2g head and used evo3 intake manifold may combine properly enough to flow better than a 1g head and 1g intake manifold. If you already have a 2g head, go for it. But again you may want to look into 1g cams, because they do flow better.

If you have a 1g head, you can pickup a good SMIM for $450 and have a system that will drastically outflow the evo3 intake & 2g head combo. Let's not forget the 1g throttlebody is significantly larger. After buying a decent 2g head and evo3 intake mani, your looking at approaching that $450 budget.

Since the op wants to 'do everything' to this engine, then he should pay to have the port work done on a 2g head, pay for oversized valves and make a custom intake manifold that is port matched to the modified 2g headports. And a custom throttlebody upgrade.

If this is out of the budget or not neccesary for his goal (he mentioned no hp goal), then use the 1g head and buy a 1g SMIM and be done with it. . .

 

[timloomis]

I was always under the impression the 1g head was built more towards top end, and the 2g head towards low-midrange torque because of the t25. Like you guys said though, the ports on a 1g are pretty big. I've never had a 2g head laying around that I could compare with though.

 

[gijoe985]

I was always under the impression the 1g head was built more towards top end, and the 2g head towards low-midrange torque because of the t25. Like you guys said though, the ports on a 1g are pretty big. I've never had a 2g head laying around that I could compare with though.

I second that. I thought a 1g intake would lean toward upper end power. Or maybe I'm confusing intakes with heads? Don't the 1g intake flow more that 2g intakes?

And for the sake of porting. I figure whatever head I'd use I'd port to optimize the performance. So if the 2g was better after porting than the 1g after porting, then it'd be better. But again, I am under the impression that 1g heads would be an upgrade if it was just a bolt on.

 

[DSMunknown]

. . . Now getting a used 2g head and used evo3 intake manifold may combine properly enough to flow better than a 1g head and 1g intake manifold.

That's what I'm banking on.