Need Advice: 2g head on 6 bolt, buy intake or get another 6bolt head??

[Sarge32]

My dilemma, I am building my 6 bolt engine. I have the machine work all done and the cylinder head is now torqued down. I have come to realize the head I had resurfaced is a 2g head due to the intake ports are smaller. Just my luck it fit over the headstuds. My original 6 bolt head is trashed due to metal going through the cam journals.

I see 2 options.

Option 1, keep head on engine and get a 2g Jm Fab street manifold

Option 2, remove head and get a used or reman 1g 6 bolt head and a new headgasket.

In a year or so I want to put a HX-35 or a Borg on to get up to 500-550 horse with inj's etc..

The Jm Fab street is rated for up to 20g turbo and the race is for bigger turbos. I have evo 3 16g I am putting on. Is the Jm Fab street manifold going to hurt me when I upgrade the turbo? I am thinking about keeping the 2g head on and getting an intake would be the best route for my Hp goals.

I am open for options and advise here.

 

[rush2252]

Advice, I saw a few 2g stock IMs in the classifieds for $20-$75 I would run the stock for now then spend money later IF you decide to buy the turbo etc.

 

[Sarge32]

Thanks Rush2252,

I was given that option earlier by a friend. I saw with the JM Fab manifold that they suggest using a 1g intake gasket in which I would still have to open the intake ports to use it. If I went with a 2g intake, I assume all I would have to do is port out the throttle body opening to work with my TB. I would hate to get an intake then have to replace later.

 

[the_mork]

DO NOT open the intake ports on the 2g head to match a 1g manifold. This will ruin the head for both flow and velocity.

I would suggest looking for an evo3 intake manifold to go with that head. It will be more responsive than a 1g head and and the evo3 IM helps manage flow up top. When you're done with it sell it for about the same as you paid for it and you'll only be out shipping

 

[lacroixdp]

I agree with Rush - keep your head and just buy a used 2G intake. Don't open up your intake ports on the head - you'll just end up screwing them up without the use of a flow bench.

 

[Gamble97]

DO NOT open the intake ports on the 2g head to match a 1g manifold. This will ruin the head for both flow and velocity.

You got anything to back this up?

 

[Sarge32]

Thanks guys,

An Evo 3 intake would be nice. I considered opening up the ports for the 1g manifold, but I reconsidered due to the amount of material needed to be removed. For my HP goals would it probably be fine. I think it would be more feasible just to bolt 6 bolt head on for the amount of work needed in opening up the ports

 

[the_mork]

I have seen some butchered up 2G heads with the 1G Look that were a waste of time to bolt on. Just because you make it huge at the gasket mounting flange does not mean it will flow any better. The real HP gains are made deeper in the runner and the bowl area where it is harder to get to.

RRE's Eclipse 2g Turbo to 1g Head Swap Tips

From DSMjim

You would be better off to buy a proper intake manifold vs. porting a 2G manifold it will make a whole lot more power.

Also the 1G manifold's opening is so much larger than the intake port on the 2g head it's not a good idea. Some people talk about port matching it however your re-designing a port which usually leads to poor results when you don't have a lot of experence in porting The intake port then would go from large to small in a very short space which would no doubt have negative effects on flow and velocity.

From Oldman

I'm not saying you should install a 1G head, I'm saying not to install the 1G manifold because port matching a 2g head to a 1G manfold will most likely hurt, not help, over all flow. I know it's hard to pull back once a project is in motion but in this case I think you should.

Blackgsx2g

Well you saw the difference in port size in the above pictures. Basically you would have a huge disruption in your intake when all the air that expanded to the 1g port size slams into a much smaller 2g port. It would create a lot of turbulence and you would probably even hurt your power output.

Do you need more? Your name is obviously in red so I'm sure you know what you're doing. Are you suggesting that you disagree with this or just asking that I clarify myself? I'm hardly a head port and intake manifold expert but I think I understand the stuff well enough to be confident in my opinions on the matter. I'm certainly not calling you out just offering to discuss this as deeply as you'd like so long as I can keep up.

 

[kthackst]

One very important thing people forget when using a 2g head on a 1g block is the head stud with the oiling port must/should be opened up. Otherwise you will have oiling problem up top. Lack of oil to the head since the larger stud is blocking the flow of the oil.

 

[Sarge32]

When they guys have the 2g heads hogged out, are they running a 1g intake? I have read with a knowledged shop the 2g head can be made to flow more than a 1g head due to more meat to work with.

 

[Sarge32]

Kthackst,

I did nothing to the head bolt holes, unfortunately my holes in my head did not need machined for the head studs. The heads that do not need machined for the 6-bolts, do they still need opened up for proper oiling to the valvetrain?