2G RIP 7 bolt....Hello 6 Bolt!

[ohlegend]

So my 1G 7 bolt is dead and I bought a 6 bolt from Miller Imports.
So I am trying to figure out all the parts that I will need.
A lot of the parts (timing and cooling) are new on my 1g 7 bolt and I plan to clean them up
and use them again.
I have a 1G cas, 1g water pump, 6 bolt flywheel, and 6 bolt oil pan. I know I will need new head studs and I need to drill out the bolt holes on the head. All of my timing components have less than 100 miles on them.

I am looking at having the block resurfaced and have all the crank/bearings/rods/pistons/rings checked out
The head is a (2G) fresh rebuild

Is there anything I am missing?

 

[spyderdrifter]

Is this 6 bolt going in a 2g or a 1g?

 

[ohlegend]

My 2g Gst.

 

[spyderdrifter]

I had to ask since I've never had a 1g 7 bolt in my cars (or really even heard of it). If you don't already have the wire harness to connect the 1g CAS to the 2g wiring, you should get that or make it as well. I've done 2 2g GSTs with a 6 bolt and built the harness the first time, and bought it the second time. That might be all you're missing, but to be sure, I'm going to look at the list I got for the swap.

 

[spyderdrifter]

Here's the list from Magnus Motorsports that I followed. I did however use things not mentioned in the list/write-up.

Parts List
• 1G CAS (91-92 Optical Effect, 93-94 Hall Effect)
• 1G Oil Cooler (90-92 MD 157670 6bolt water cooled oil cooler)
• 1G Water Pump
• 1G Oil Pump/Front Case
• 1G Timing Belt necessities
• 2G Engine mount (modified) use 2G engine mount trimmed, with 1G tensioner arm
• 1G Timing Belt Covers (modified)
• 1G 90-92 6-bolt block (with whatever internals)
• 1G 6-bolt Flywheel
• 2G Starter Mounting bracket
• 1G Water Pipe
• 1G lower radiator hose
• 1G Thermostat housing/ Water Neck
• 1G 6-bolt oil pan Balance shafts (remove them or keep em, its up to you, we take them out)
• 2G Alternator
• 2G Power Steering Pump
• 2G A/C 2G Belts


The way I did it, was I used all 6 bolt parts for the block, minus the engine mounts, I used all 2g parts there. And all 2g parts for the head to include the t-stat housing, main water pipe, and radiator hoses. I did my own coolant setup for the turbo since 6 bolt blocks don't deliver coolant from the block like 7 bolts. And of course, drill the head bolt holes a d use 6 bolt head bolts.

 

[ohlegend]

Ok, good info! I cant wait for the short block to arrive. Hopefully it has a lot of the parts that I am going to need. I am planning on replacing all timing components and the front case. and transfer my BSEK from my old block to the new one. Also relpace the bearings and rings.

 

[spyderdrifter]

Looks like you got a good plan to start with.

 

[ohlegend]

Would it be ok to use my current pistons (New rings) on my 6 bolt setup? It would save me from having to buy new rings.

 

[spyderdrifter]

So r I forgot to reply to you sooner. I don't right off remember the setup, but I think you can use 7 bolt pistons with 6 bolt rods. However, you can only do this after having very specific machine work done on them. I'd just stay with whatever matches the engine you're using.

 

[ohlegend]

The pistons on the 6 bolt hit the valve train...so they are kind of marked up.

 

[spyderdrifter]

That sounds pretty sh!tty if you bought the 6 bolt from Miller.

 

[spyderdrifter]

If you're using a 6 bolt engine, and want to substitute 7 bolt parts, you'd want to do something like this: http://www.dsmtuners.com/threads/evo-8-pistons-in-6-bolt.394744/

Post #8 has a diagram.

 

[rough]

Curious.. How did your 7 bolt die?

 

[ohlegend]

Bearing on rod 4 is toast, possibly a spun bearing.

You must be logged in to view this image or video.

 

[rough]

Bummer!! Where you doing a pull or just casually driving?

 

[spyderdrifter]

My last 7 bolt got a spun bearing on rod 1 or 4, can't remember, but was only casually driving to work. So can happen on any engine load.

 

[ohlegend]

I just did a pull, (I got it up to maybe 80, so not a really hard pull) stopped at a stop sign, turned right and it started knocking.