1g 6bolt head vs 1g 7bolt head

[greddy_1700]

Just curious if anyone knows the actuall differences in these two 1g heads. I know about the 1g vs 2g head differences, but not the 1g 6 bolt versus 1g 7 bolts.

Thanks!

 

[BLINKY619]

mmmm im curious too

 

[DSM-Hottie]

I heard that the oil passages are different....other then that I have no idea either. Im told I have a 6bolt head....but IDK.

 

[JEFFREYCASTGSX]

About the only big diffrence is the clearance for the 11mm head bolts, the intake/exhaust ports are the same.

 

[shockwaveaz]

So they are just different head bolts and oil passages? would their be a benefit from one or the other I wounder. maybe it would depend on the set up your doing?

 

[cutty2fast]

i believe the 6 bolt intake ports are larger???? and 6 bolt intake uses a larger bore throttle body

 

[Oliver@Slowboy]

i believe the 6 bolt intake ports are larger???? and 6 bolt intake uses a larger bore throttle body

That is a 1g to 2g difference.

I have seen some *supposedly* late 94/early 95 (or at least that is what I believe them to be they may be Hyundai) heads with a 1g style t-stat housing and 2g style intake runners.

Maybe someone can help me with what application this really is, I have seen less than half a dozen like this (that's why I think they may be Hyundai)

Oliver

 

[Redwidow]

Oliver - The head you speak of is the Hyundai Head, And it does have the 1G head bolt holes, the 1G thermo housing and and 2G style runners.

OP - To the best of my knowledge, the only difference between the 1G 6 bolt head and the 1G 7 bolt head, is the size of the head bolt holes. Just as in the case of a 1G head compared to a 2G head, the 1G 7 bolt has 11mm holes, and the 1G 6 bolt has 12mm holes. If someone happens to have a known 1G 7 bolt head and could take some measurements for comparison, that would be great.

 

[KazooGS-T]

Oliver - The head you speak of is the Hyundai Head, And it does have the 1G head bolt holes, the 1G thermo housing and and 2G style runners.

OP - To the best of my knowledge, the only difference between the 1G 6 bolt head and the 1G 7 bolt head, is the size of the head bolt holes. Just as in the case of a 1G head compared to a 2G head, the 1G 7 bolt has 11mm holes, and the 1G 6 bolt has 12mm holes. If someone happens to have a known 1G 7 bolt head and could take some measurements for comparison, that would be great.

I have a 1G 7bolt head. The ports are the same 1G 6 or 7 bolt. The big gain here is that 2G guys can run a 1G head without worrying about the head bolts.

 

[Redwidow]

OK so to make it perfectly clear:

1G 6 bolt head: Large runners, 1G thermostat housing, and 12mm Head bolt Holes

1G 7 Bolt head: Large Runners, 1G Thermostat housing, and 11mm Head bolt holes

Hyundai head: Smaller 2G style runner, 1G Thermostat housing, and 12mm Head bolt holes

2G Head: Smaller runners, 2G thermostat housing and 11mm, head bolt holes.

Another I figured out when using a 2G head on my 1G was that the 1G thermostat housing will bolt up to and work on a 2G head. Although I do not know if a 2g thermostat housing will work on a 1G head.