head difference

[cooliomo]

are the 6 bolt head and 7 bolt heads, different? if so how can i tell the difference. i searched.

 

[solidviper89]

I don't know specifics... But 6bolt heads have bigger ports(higher flow)

2g 7bolt heads have better angle into cylinder(?), smaller port makes higher velocity, makes more torque...

I have zero first hand experience, this is just from things I have read. Dsmtuner's has a few threads on the differences; i'm sure someone with actual knowledge can chime in.

 

[Barnes]

SV, I think you are confusing a 7-bolt head with a 2g head. 7-bolt heads have the same ports as 6-bolt heads. 2g heads have the smaller ports which are generally better, or people use 2g heads as cores because you can do a raised runner style and get a better angle into the valve.

The differences I can think of are A)Small head bolt holes and B)The far left and right exhaust manifold studs are 10mm instead of 8mm. You can use a 7-bolt head on a 6-bolt engine IF you have the head bolt holes bored out to accommodate the larger 6-bolt head bolts or studs.

 

[solidviper89]

Yea I meant that... the 7bolt head that came on 2g's /ubbthreads/images/graemlins/smile.gif 95+ /ubbthreads/images/graemlins/smile.gif

I know that some 1g's got the 7bolt, but i always remember it as 2g dsm's have the 7bolt.

 

[cooliomo]

ok thanks i guys i really appreciate it!

 

[TRBODSM]

The 1G 7bolts have the two 10mm studs on the bottom ends also.

 

[fuel]

Lancer Evo 1, which is a 7 bolt engine has the smaller ports too. They were around in 1992.