what is the diffrence between 1g 6 bolt and 7 bolt heads

[myturbo]

since when is anything diffrent between 1g 6 bolt head and 1g 7 bolt head ????

 

[delta448]

The very early 6 bolt heads have an oil pressure relief valve in the oil distribution block and all 6 bolt heads use a 12mm bolt/stud where the 7 bolt heads use an 11mm.

 

[myturbo]

The very early 6 bolt heads have an oil pressure relief valve in the oil distribution block and all 6 bolt heads use a 12mm bolt/stud where the 7 bolt heads use an 11mm.

ok well i just got a 93 head p&p of a 7 bolt and m moter is early 92 6bolt so would it have the pressure relief valves

i guess i might be sellg the 7 bolt head then

 

[Ahsieh2]

Is one better than the other for any reason? Why did they get rid of the oil relief port?

 

[myturbo]

well i checked the head studs and they dont fit this sucks so bad

 

[alansupra94]

well i checked the head studs and they dont fit this sucks so bad

You could ask a machine shop to tap the holes. However, alumium is not a very fragile.

I personally would just source out a 6 bolt head.

 

[f'edupTalon]

So what would happen if you put a 7 bolt head on a 6 bolt block?

 

[delta448]

You'd have to have the bolt holes drilled out to fit the larger diameter stud/bolt. The rest is basically the same.

ok well i just got a 93 head p&p of a 7 bolt and m moter is early 92 6bolt so would it have the pressure relief valves

No, not likely unless the head or the distribution block in the head were previously swapped. Don't quote me on this, but I believe the 89-90 were the only heads with the pressure relief valve in the distribution block.

 

[fwdmaster]

So what would happen if you put a 7 bolt head on a 6 bolt block?

If you get the late 92-94 7bolt head and get it enlarged to 12mm head bolt size and installed it into a 6bolt block, it will run the same as if you had a stock 6 bolt head on,basically the difference between a 6bolt head and early 92-94 7bolt heads, are that the head bolt size is different


6bolt head-12mm

7bolt head-11mm