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Ring Gap - Total Seal Gapless Rings

6K views 15 replies 7 participants last post by  ERP 
#1 ·
I rebuilt my 2.3 about 3k miles ago but for several reasons the rings didn’t seat. I am putting in Total Seal, Gapless 2nd rings this time around. But it is not clear what the correct ring gap should be, so I am hoping this post can sort some of it out.

For the initial 2.3 engine swap the cylinder bores were on spec at 3.543” +/- .001. I bought a ring set from The Saab Site but the 1st ring gap measured 0.023”-0.024”. This is over the Haynes Manual specs, listed below.

1st: 0.012-0.020” (0.30-0.50 mm)
2nd: 0.006-0.026” (0.15-0.65 mm)
3rd: 0.015-0.55” (0.38-1.40 mm)

This time around I am using the Total Seal, chrome top ring and gapless 2nd ring, again I am measuring 0.023”-0.024” for the 1st and 2nd ring. I have talked to Total Seal and they have assured me this is fine for a gapless 2nd ring. For a turbocharged engine they use the equation; Ring Gap = Bore x .0055", which is just under 0.020” for my engine.

I feel confident with the Total Seal rings and I am going to install them. I would just like to know what others have gotten for ring gaps when rebuilding their engines.

For those interested the ring groove sizes in the 2.3L pistons are; 1.75 mm, 2.0 mm and 3.0 mm
 
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#3 ·
Eric you were reading my mind!
I was just about to start a ring thread but you beat me to it. I am also rebuilding and trying to use stock B234 pistons.
I got my OEM set form the dealer and here are my gaps:
upper compression ring: .021-.022"
lower compression ring: .027"-.028"
oil scraper: I think it was in spec but don't remember.
Am I o.k.?
I calculated max Saab spec for the upper and lower compression ring to be .01956" and .0256" respctively. I am a bit over that. I am using stock rings, not total seal.
I have been talking to John Williams about this and sent Vigge a pm, no respionse yet though.
I have seen some of the DSM guys runnin up to .022 and .024" on the top ring so it might be o.k. but I am trying to be careful. I don't want it burning oil and loosing compression.
Any thoughts or opinions would be appreciated.
 
#4 ·
I feel more confident with my 0.024" gap because of the 2nd gapless rings. But my first break in with Saab rings and a 0.024" gap went through a lot of oil and compression was low, 108-135 psi. For my break in there were two other major factors that prevented the rings from seating, so I have no idea how much of a roll ring gap played in it.

I think the only place to get an answer on your rings is a Saab dealer tech. Someone with years of expeirece rebuilding Saab engines.
 
#6 ·
Well I posted up on saabnet so maybe Swedecar will answer, he's a saab tech on the west coast I think.
It's kind of odd that a lot of rings are being made nowadays so the top comp. ring gap is tighter than the bottom comp. ring gap, but others like total seal (and i think the JE ones might be the same) are running top gap and second no gap.
I will wait and see what Vigge and maybe Swedecar say. Do they make oversized rings? Can I return these to the dealer if I already put them in the cylinder to check?
Either that or maybe someone will want to buy them.
So Eric:
Did your Deves and the total seals have the same top ring gap of .024"?
 
#7 ·
running top gap and second no gap.
Just to be clear, gapless rings aren't acutaly gapless. There are two rings in one groove. One is standard size and the other is thin like an oil ring. Both rings go in the same groove with the gaps 180 degrees apart.

So Eric:
Did your Deves and the total seals have the same top ring gap of .024"?
Yes, but I think it was just coincidence.
 
#8 ·
Yeah I think some of the designs are actually stepped-they have like a ramp in them where the ends overlap.
I am really surprised no one has chimed in by now with additional info on ring gaps.
I know there are others out there that have built the B234 themselves.
I'm really over stock spec like by .0015" which isn't that much.
 
#9 ·
I would like to hear from some people that actually remember what end gap they had. I talked to Nick about it today and had a good point. When you hone the cylinder and consider the entire circumfrence Sp? then to be a few thousands over sounds about right.

Saying that, my je forged pistons with pro seal rings, had a spec of .017" and I have heard from the racing croud making 650bhp, the ring gap they like for both honda and evos was .022" top and .026 for second ring.

I have a spec sheet with my pro seal rings and it says stock set-up minimum gap is .015", turbo-street/strip .017", Late model, .017", nitrous motor .022" and full on circle track .024". Does this apply to forged pistons only? My first set of total seal rings were tight, I measured them at .016" and it looked like the top compression ring had butted together and caused the ring to oblong, it had lost the springyness and this is the motor that cracked #4 piston...

My engine builder put that motor together, I think he forgot to file the end gap and just put em in the cylinders...

Its better to be a little lose than it is to be too tight. Both you guys should be good for 650bhp and nitrous:roll:

John
 
#10 ·
Yeah I guess if I was going with forged pistons I'd be all set for 650 bhp, but that's not my goal.
I think it will be o.k. , like I said before I'm only like .0015" over max spec on each and that isn't much. The cylinders had .0015" taper from top to bottom (total of .003" taper).
I think I'm gonna go with it. Like you said better too loose than too tight.
Thanks for your help John, and now we at least have a small amount of info on this.
It would be nice if others that have rebuilt these engines could chime in though.
 
#12 ·
Well they are saying max is Bore x .008" and Im at Bore x .006" so i guess it should be o.k.

90 mm bore = 3.54331" bore

3.54331" x .006" = .0213" gap which is pretty much what i have.
A lot of the n/a guys use Bore x .004" but you really need to run the rings a little looser on a turbo engine because the heat is so much greater-you don't want the ends of the rings hitting each other when they grow form thermal expansion, this is how the rings and pistons break.
 
#13 ·
hmm im another who cant remember what my gaps were :-| all i know is my bore was towards the outer tolerance of wear nothing majour just a little worn it did have over 200,000 on it. so i didnt need to alter the rings at all, im guessing this is beacuse they cover all the way up to the maximum standard bore size, any less ie nearer the new size id expect them to need tweaking to fit. i have no obvious oil consumption problems after 5000miles though. might need to whip the head off again though as with the b234 block and b235 head the coolant seems to be boiling in the top hose :? i think i need to drill an eaxtra hole in the block to match the head, but then ill need to modify the head gasket.... i think ill start another thread :lol:
 
#16 ·
Update

I’ve got my gapless rings installed and the engine put back together. I followed the Total Seal instructions for break-in and used their dry ring break-in compound. Only 160 miles on the rebuilt engine and the rings are sealing up very well. Vacuum is 16 mm at idle and 18-19 mm during deceleration. There was zero smoke out the back and the engine power and idle is very smooth.
 
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