question about 1g 6bolt/7bolt...

[spidy3]

I am doing a rebuild soon and deciding on if I want to go with the 2g pistons or 1g pistons. If I dont need to bore out cylinders I am sticking with 1g pistons probably. I am looking to get total seal rings, but when I looked on their site it only lists 92-94 or 93-94 for 1g's.
So my question is.... Is there a difference between the pistons or engine bore between the 6bolts and the 7 bolts in the 1gs? or will getting rings for stock pistons for a 1993 4g63t be the same as ones for my 1991 4g63t?

Thanks...


Dom

 

[99gst_racer]

The rings will vary depending if your pistons were from a 6-bolt or 7-bolt.

I'm not sure what the difference is though. The bore is the same and the 1G 6&7-bolt rings both seem to share the same axial height: 1.20mm, 1.50mm, and 3.00mm.

But if I check manufacture part numbers, they all have a listing for 6-bolt engines, and a dissimilar listing for 7-bolt engines, so something must be different about the rings themselves.

The 2G pistons have a shorter axial height on the oil ring, hence a more narrow groove on the piston. A 2G oil ring measures to be 2.8mm as apposed to 1G's with the 3.00MM ring. But I still can't figure out what the difference is between the 6&7-bolt 1G's.

For a 1G 6-bolt, I came up with a Total Seal part number CR3164. Add -20 to the end for .020 oversized.

Do you plan on using a gapless top or 2nd? Or just conventional rings....

 

[spidy3]

Thanks for the info, esp. finding the part number. I called them before about it and asked if they knew a difference and they said they didnt know. When I talked to them I also asked what would be better for having for the rings but i cant remember what they said. would top gapless or 2nd gapless be better?

Thanks,

Dom

 

[99gst_racer]

Thanks for the info, esp. finding the part number.

No problem.

would top gapless or 2nd gapless be better?

That would vary per application. What are your goals with this engine? What turbo and how much airflow and compression will it be seeing?

There aren't really any downsides to the gapless rings. They are more consistent, have less friction, and give more engine vacuum. But they do cost more.

If you go gapless, do a top gapless instead of a 2nd. Also, always make sure you file fit the rail as well as the ring.


If you are building a motor for street performance in the 250-350 HP range, there is nothing wrong with just using conventional rings. Gapless rings are nice (especially for engines with nitrous or forced induction), but they are not needed for most people.

 

[spidy3]

My goal is to put down atleast 300awhp. I have been told by some that my mods should put me around 350awhp which i would definatly take . Im planning on keeping my EvoIII16G for a while and run around 22 psi with it (mite upgrade to 50trim or similar later on). My compression will be around stock(7.8:1) except for what the total seal rings bump it up to (i know it'll be very little if any). All my current mods are in my profile with the acception of the Comp 101200 cams that I just purchased but wont be in car til rebuild (will be getting valve springs also).
I also thought that with less blowby from the total seal rings it would help my spool time be a little quicker and help out with the cams.


Dom