2G 2G turbo/1G non-turbo head differences.

[98gs-tsleeper]

I have a 98 GST and was looking at the heads. A friend of mine had a Laser that he had the head ported and polished. My question is is there any difference between the turbo and non-turbo heads and if so how different are they.

Also is Laser is a '91. Would I be able to use it?

This is my 1st tuner car and am still learning the ropes on imports.

 

[1320Motorsports]

Only difference I can think of off the top of my head is the cams, non-turbos and automatics have different cams

There may be more differences, valve springs come to mind, but I cant recall right now

Matt

 

[tt281gt]

I want to know too. There are many 1g n/a heads in the jy here!

 

[VerbalKint]

From what I have heard and read, the only real difference between the NT and Turbo heads in the INTAKE Cam.

Specifically, I have only heard, or read, in regards to the 91's, as this is what I have, but to my knowledge (and word of mouth from a performance shop) that's the only real difference in 1g heads.

 

[tsi9973]

i had a an extra 1g non-turbo head i had rebuilt, put in the turbo cams and slapped it on and worked great. on the old turbo head went 12.86 @ 105 on the non-turbo head (mild port and polish) went 12.61@108. so i would say no difference.

 

[i1nk83]

The only differences are the cams (obvious), the head bolt diameters, the size of the ports and the oil port in the CAS side. It is used for oiling the turbo in the 63t's and is not used in the NT 4G63's.

When you have the valve cover off you will see the piece I am talking about in between the cams on the CAS side. This needs to be switched with one from a turbo model. Other than that they are exactly the same springs, etc.

But you can't use a 1G head on a 2G unless you change the intake manifold too because the the different in intake port sizes. The 2G manifold won't seal.