2G 1G 7-bolt head and 6-bolt block in a 2g

[JackStieben]

Hello, I acquired a '92 6 bolt block a while back for cheap. I also got a 7 bolt head but it appears to be from a 1g. It has the CAS under the intake cam gear and the other side is plugged. I know I'll need to port the holes for the head studs but what else do I need to do to use this head? How do I connect the cas? Can I just install the 2g CAS already in the car? Sorry, I am a bit lost in the differences and can post any photos if need be. And do I use the 2g intake manifold or 1g?

 

[Pure92TSi]

If it is a 1g head you will want to use a 1g intake manifold so the port size will match. 2g intake ports are much smaller

 

[jamarh85]

From your description it sounds like you have a 2ga head

 

[TehRiceBandit]

If your 2g IM bolts up to the head it's a 95-96. (I'm talking about runners matching up)

http://www.dsmtuners.com/threads/95-96-swap-into-a-98-eclipse-gst-help.386107/

 

[JackStieben]

I measured the height of the intake runner on my 1g intake and the head. Must be a 2ga 7 bolt. What do I need to do to use it in my 2gb? Can I put in my CAS and just use a different cam gear to replace the sensor on the intake side?

 

[19Eclipse90]

Basically, yes.

• Since you're using a 6-bolt block, drill out the head bolt mounting holes in the head to 1/2".
  
• If the head has an intake camshaft in place already, make sure the end opposite the gear is drilled and tapped for a M8 x 1.25 mm bolt, roughly 1.5 inches deep. If it is already tapped, you're set to bolt your existing 2Gb CAS up and go. If necessary, the other alternative is to swap the camshaft from the head currently in your car into this head and go on.
  
• Use the 2G intake manifold.
• I'd suggest using the 1G thermostat housing and water pipe setup because of the 6-bolt block.

The sensor behind the cam gear is irrelevant at that point. You can swap cam gears if you like and remove the sensor or simply leave it all there.

 

[JackStieben]

Basically, yes.

• Since you're using a 6-bolt block, drill out the head bolt mounting holes in the head to 1/2".
  
• If the head has an intake camshaft in place already, make sure the end opposite the gear is drilled and tapped for a M8 x 1.25 mm bolt, roughly 1.5 inches deep. If it is already tapped, you're set to bolt your existing 2Gb CAS up and go. If necessary, the other alternative is to swap the camshaft from the head currently in your car into this head and go on.
  
• Use the 2G intake manifold.
• I'd suggest using the 1G thermostat housing and water pipe setup because of the 6-bolt block.

The sensor behind the cam gear is irrelevant at that point. You can swap cam gears if you like and remove the sensor or simply leave it all there.

Thank you! So basically all 7 bolt heads are the same, but the cam shafts and sensors are different. I'll probably reuse my cams and sensor.

 

[19Eclipse90]

The size of the intake ports is the biggest visual difference between 1G 7-bolt and 2G 7-bolt heads. The others would be that a 1G 7-bolt head does not have provisions for a 2G thermostat housing nor does it have provisions for a 2Ga CAS (behind the intake cam gear).