6 bolt + 7 bolt = ???

[awinterstale]

ok i need some advice im having trouble searching for... I have at home an extra 6 bolt engine with 1g intake manifold. In my 95 gs-t now I have a 7 bolt. Between the two i want to do a rebuild but on a tight budget i want to re-use as much as i can.

What would be a good combo to use between the two? What new parts should i buy? Please help!!!

 

[ReaperGSX]

Im not a mechanical genius but I know the 1G and 2G heads differ so i dont know if you can interchange those parts. But if you look around you can get rebuild kits or patrs and rebuild the whole engine for around $1200.

 

[tbonitz301]

Use the six bolt as your platform. Keep the head and intake mani on the sixbolt. take the 2g exhaust mani and pistons for the six bolt. Keep the 1g rods in the sixbolt

 

[awinterstale]

ok thats what I was also thinking to do. Do I need to do any thing to the 2g pistons?

 

[tbonitz301]

I'm pretty sure there is machining involved. Not really to sure though. I'll leave that to someone else

 

[JaxTalonTSi]

Machine work must be done to use 2g pistons on 1g rods. For a relatively small turbo (16g or smaller) build, I would use a 7 bolt head on a 6 bolt shortblock. The head bolt holes in the head must be carefully drilled out a few millimeters bigger to accomodate the 6bolts 12mm head bolts, but aside from that, it's a straight bolt on. Use the 2g intake and exahust manifold on the 2g head as well.

 

[cmptrphreak]

Hey sry too steal the post but why would you want the 2g head if you have a 16g or smaller?

 

[JaxTalonTSi]

Hey sry too steal the post but why would you want the 2g head if you have a 16g or smaller?

The 2g head is a great flowing cylinder head design. But after you reach a certain point (big turbo, lots of boost, lots of airflow) the small 2g port size will hold you back. But in my opinion, for a basic bolt on street driven DSM, with your basic 16g and supporting mods, the 2g cylinder head design will offer more low and mid range power.

 

[awinterstale]

Its a 5 speed. I'm thinking about just going with the 1g head and bottom so there will be less down time on the car. Can I use the 2g intake and exhaust manifolds with the 1 g head? Or should I use the 1g intake manifold since I already have it?? I'm not looking for extreme horsepower so I think I'm gunna pretty much stay stock in the bottom end and get a valve job on either head I use. What do you guys think?

 

[turboking15]

use the 2g exhaust manifold as it is bigger, also use your 2g o2 housing. in regards to the intake manifold if you use the 1g head use the 1g intake manifold, the 1g ports are bigger than the 2g so the 2g intake mani would restrict flow.

 

[JFZERO ECLIPSE]

You was saying about less downtime. Personally I would go with the 6-bolt bottem end....Machine the rods to fit the pistons, Then Drill the head out just a little bit for the 6 bolt head bolts....(Might want to get some arp headstuds...)

Just for ease of installation use the 2g head....Yes it's ports are smaller but they offer a much better design/ than the 6 bolt heads....2g's have a pretty straight forward path, 1g's slant down quite a bit making turbulance....2g heads offer a much higher velocity than 1g heads again due to their design...

Plus if you are going in a 2g you will have to do wiring changes and what not to accept a different cam angle sensor...may get a check engine light from not using the MDP....There are many other reasons...but I dont have the time right now to type them all down....

If your going for the cheapest and most reliable way to get your car back on the road, I say 6 bolt block 2g head...

Also as a side note....When using 1g block and 2g head you use the 2g water pipe....benefit to this....easier to swap turbos IMHO....1g water pipes you got that 1 coolant line that runs under the turbo to the water pipe....it can be a total PITA sometimes.....2g's just have individual coolant lines that run to the t-sat housing....much much easier to change a turbo...bolt the line on then just gotta mess with a small coolant line rather than lifting and trying to hold the turbo up in place....(Gets heavy after a while...)

But it's not my car, I'm not the 1 doing the work it is your choice after all...I'm rebuilding a 7-bolt block and head to see what it can handle...

Also, when swapping a 6-bolt in a 2g (Head doesn't matter) the compression ratio of the pistons will cause the car to run not up par from stock...2g is 8.5:1 when 1g is 7.8:1 May not sound like much but remeber the cars fuel map are set up for 8.5 not 7.8....