identifying 2g turbo pistons, help please.

[Bohrn]

I have what I believe to be 2g pistons on 1g rods, but I am not sure if they are 2g turbo or 1g n/t pistons.

Obviously the dish is deeper on my stock 1g turbo pistons, so I know that the new pistons are higher compression, but how do I tell if they are in fact 2g TURBO pistons?

I have heard that 2g pistons are supposed to have thicker ring lands than 1g turbo ones, but on these, the top ring land is obviously smaller.

is there a casting mark or a measurement, or something I can compare?

I don't have an N/T piston here to look at, but I do have 1g turbo and these supposedly 2g turbo ones.


Thanks for all your help

PS, the build is almost done, very nice head, bshaft work done, pistons out, new parts all bought, so I need the information fairly soon so I can finish the build.

 

[DSMGraveyardinc]

I have what I believe to be 2g pistons on 1g rods, but I am not sure if they are 2g turbo or 1g n/t pistons.

Obviously the dish is deeper on my stock 1g turbo pistons, so I know that the new pistons are higher compression, but how do I tell if they are in fact 2g TURBO pistons?

I have heard that 2g pistons are supposed to have thicker ring lands than 1g turbo ones, but on these, the top ring land is obviously smaller.

is there a casting mark or a measurement, or something I can compare?

I don't have an N/T piston here to look at, but I do have 1g turbo and these supposedly 2g turbo ones.


Thanks for all your help

PS, the build is almost done, very nice head, bshaft work done, pistons out, new parts all bought, so I need the information fairly soon so I can finish the build.

This is right up my alley, let me try to help ya out here:

1G Turbo has the deepest dish, 7.8 to 1 compression ratio ( will have a T )
1G NT Pistons will have the highest dish, with 9 to 1 compression ratio. ( No T)
2G Has a medium dish, and has the 8.5 ( This one says F1 on the piston, with a T)

On the rods, there are only 21mm, and 22mm.
For stock rods, ALL 6 bolts are 21mm, and all 7 bolts (92-99, and new Evo's) have 22mm

If you have a 2G Piston, you will have a 22mm wrist pin, if you have a 6 bolt rod, it would have been Frankenstein'd to a 22mm. How you can tell if its a 6 or 7 bolt rod, is by comparing it to pictures, or by checking what crankshaft the engine you just pulled it from is. 6 bolts have a wider bearing surface than the 7 bolts.

BUT there is 1 last excection. You could possibly have a 6 bolt rod, that has been modified to a 7 bolt crankshaft. This is when the rod has been blanchard groud thinner, to fit the crankshaft. This is very hard to tell by the naked eye. There has been about 1 mill ground off each side, to make it fit that 7 bolt crankshaft.


What it sounds like to me, if you have a "Deeper Dish" is that you have a plain old 1G Turbo Piston, and you are comparing it to a 1G NT Piston, with hardly any dish.

Hope this helps,

Jon

DSM Graveyard (Home of the Frankenstein )

 

[Bohrn]

I was actually hoping you would reply

the originals are definately turbo, so I am comparing it to that. My car is a 91 awd 5spd turbo and I pulled them myself.

And they are definately big rods, as I have my original rods to compare them to as well. And a small rod kicking around so thats for sure. These have new ARP rod bolts installed and the big ends resized, all work was done at a good machine shop.

I am ONLY worried about them being 1g N/T pistons as the ring lands are NOT bigger on the "2g" pistons as compared to my original 1g turbo slugs.

The pistons in question do have the big "T" stamp in between "63d" and "F1" so I guess they are turbo 2g after all?

 

[DSMGraveyardinc]

I was actually hoping you would reply

the originals are definately turbo, so I am comparing it to that. My car is a 91 awd 5spd turbo and I pulled them myself.

And they are definately big rods, as I have my original rods to compare them to as well. And a small rod kicking around so thats for sure. These have new ARP rod bolts installed and the big ends resized, all work was done at a good machine shop.

I am ONLY worried about them being 1g N/T pistons as the ring lands are NOT bigger on the "2g" pistons as compared to my original 1g turbo slugs.

The pistons in question do have the big "T" stamp in between "63d" and "F1" so I guess they are turbo 2g after all?

Haha, thanks for the complement, Yep those would be 2G's.

Here is our listing, for a picture,
DSM Graveyard - Your #1 Source for Used DSM Parts!

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

Now, here is the next thing. There are 2 different 2G Pistons. There is a early 95, and a late 95+. The later has has a 2.8 oil ring land, and the early has a 3.0. The top and middle ring stay the same. When shopping for rings, you will want to know which one you need. It sucks when you get the wrong rings.

You can measure it with a normal caliper, by using the inside diameter part.

Good luck with the project, and feel free to give us a buzz if you need help!

Thanks!

Jon

 

[Bohrn]

oh crap, I need to measure that oil ring land as I have the rings aready!

I am a professional mechanic and the listings in our catalogues didn't show different part numbers for '91 and '95 turbo ring sets.

I bought a set of Sealed Power rings part number E-522KC. I believe these are correct for a 95 piston. I will have to measure them at work with my calipers.

 

[Bohrn]

well it turns out I have the smaller oil ring lands. I can't fit the 3 part oil ring into the land on those.

Does anyone happen to have a Sealed Power number for the correct one?