1G six bolt head, 1g 7 bolt block

[milby43]

I saw a couple threads about it. But it was for a 2g 7 bolt block. My question is, what do I have to make a 6 bolt head from a laser fit? If the other threads are right, I have to drill out and tap the holes in the 7 bolt block?

Can't I just open up the 6 bolt head holes for the larger 7 bolt head studs?

Is there anything else that needs to be done? In the threads that I saw, someone said something about the CAS. But both head and block are from a 1g which uses the same setup. CAS on rear of engine, on exhaust cam.

Anything else would be helpful!

Thanks a bunch guys!
Andrew

 

[TexasTurbo]

The studs that go in a 7bolt are 1mm smaller than the studs for a 6bolt. You would not want to drill anything, just use the 7bolt studs. Tapping stud holes in a block sounds like a bad gig to me anyway and would likely be asking for head sealing problems if not done by a professional.

 

[LiquidX]

There are a few tech articles that BogusSVO made about what you should to to the head.

11mm studs will fit in the 12mm head holes. I don't know why you would want to put a 6 bolt head on however.

 

[BogusSVO]

Leave the block alone.

As stated above get the head studs for the block, Should be 11mm
The 6 bolt head will be set up to accept 12mm studs.

You may want to do this tho...
http://www.dsmtuners.com/forums/newbie-forum/341028-4g63t-head-oil-port-mod.html

 

[donniekak]

Wrong, how would 7 bolt 11mm studs fit fine in 12mm holes??

You need to bore out the head stud holes on the head 1mm to use the larger 6 bolt studs. There are a few tech articles that BogusSVO made about what you should to to the head.

He's using a 7-bolt block.

 

[LiquidX]

Ah crap, i must have read wrong. Thank you.

 

[milby43]

Its just this head has been rebuilt, I'm going to switch it out, get ARPs and new head gasket. That way my car isn't out of commission.


So just get head steads for a 6 bolt block? If they are 1mm bigger won't they not fit in the block threads?

 

[BogusSVO]

What you get are the ARP studs to fit the block, in your case, the 7bolt Head studs, that are 11mm.

The 1g/6bolt head you want to go to will have 13mm head bolt/stud hole in it from the factory.

The 13mm holes in the head will slip right over the 11mm ARP studs that you install in the block.

Use the 7bolt 11mm ARP torque spec.

 

[milby43]

Im getting these correct?
DSM Graveyard - Your #1 Source for DSM Parts!

 

[LiquidX]

Yes, you have a 7 bolt block and those are 7 bolt studs.

 

[TexasTurbo]

The main point that anyone is trying to make is you need to use the studs that go to your engine block. The head either needs to be drilled to accept bigger studs (not the case here), or it will just work with studs that are smaller than the ones that mated that head to the 6bolt it originally came on (this is the case here).

Cliff notes: buy the studs for your engine block you're using.

 

[spadepro22]

So if I ever need a new head and couldnt find a 1g 7bolt head, I could just slap on a 1g 6bolt head and go? It wouldnt be a problem with the 1mm smaller difference?

 

[olddsmer]

You should get a 7 bolt head.The 7 bolt studs you need are 11mm. The holes in the head are 12mm. The head will move some under a load because there will be 1mm of slop there. The only thing really fastening the head will be the stud nut. I am afraid that won't be enough. Otherwise
you will need to tap the block to 12mm.

Regards
Greg

 

[bryanwheat]

You should get a 7 bolt head.The 7 bolt studs you need are 11mm. The holes in the head are 12mm. The head will move some under a load because there will be 1mm of slop there. The only thing really fastening the head will be the stud nut. I am afraid that won't be enough. Otherwise
you will need to tap the block to 12mm.

Regards
Greg

Incorrect. The dowel's align the head to the block, the bolts just clamp it down. The 1g heads are pretty much identical, the 1g 7 bolt head has the same size bolt holes as the 6 bolt head. I've got both sitting on the shelf.