Totalseal rings

[modok]

There are a lot of different ring pack combinations that work well, and they probably work in slightly different ways.

The only real COMMON principle, why three rings, I tend to think of, is thus:
The top ring ends up barrel faced, because..... many reasons.
The second ring is not subjected to as much force, so it can stay sharper.

Gapless or not, doesn't necessarily contradict that, but it also doesn't really help it either.

[GARY C]

he has found that the gapless 2nd is a good fix for keeping alcohol out of the oil for guys that can't tune.

That is one thing I don’t fully understand. Everything my pea brain understands tells me to let go of what ever gets past the top ring. The gap less second could hold pressure between the top and second ring, causing flutter or sealing issue. Why not go gapless on the top ring to prevent the buckets of ally from getting to the oil. I truly ask this and am willing to listen to those who run ally and do this as I enjoy building and tuning stack injected ally engines. In years past I have turned my oil pans into ally storage containers but got away from doing that over a decade ago. I still have lots to learn though so please share.

Paul

I didn't really question him on it but my guess would be that he is primarily dealing with dirt trackers and the gapless 2nd ring set is a little bit cheaper and he found it to work and much easier than to try to convince the owner to work on his tune.

If I think to ask him next time I talk to him I will get his take on why second and not top, could also be that he has not experienced power loss with the second ring style like he has with the top ring style.

It would be interesting to know between the guys that have good luck vs bad luck with the top ring style, are they both running different second ring end gaps and what size gap are they running?

When I first got into engine almost all rings were gapped with a larger top ring gap than the second, now most ring mnf recommend a smaller top gap than the second, so what changed, rings or knowledge and is one really better than the other?

[modok]

I think all the cases I've seen specifying the larger second gap are using second rings that are clearly sharp oil scraper types, napier hook, or tapered/reverse twist.
But some modern and well respected engines the second ring does appear to be more like a compression ring.

[n2xlr8n]

I've used TS Gapless top (AP steel in recent) in all my boosted applications.

All of the pistons used had the anti-flutter machining between the top and 2nd ring grooves.

A AC Delco vacuum pump was used on every engine, roughly 5-8" vacuum.

I have a really good machinist.

Never had a single issue.

[FC-Pilot]

I brought up the alky thing as I have seen that ring package in NA and blown alky stuff from respected builders a number of times. I was wondering if there was some experience or knowledge that I needed to learn and except.

Paul

[BradH]

I don't understand the question. Gapless rings are compatible with gas ports. The engine I mentioned a few posts back has lateral ones in addition to the gapless rings.

I'm just trying to understand the fuss. I suspect any issues from a gapless ring revolve around the induction stroke more than the compression/combustion stroke.

Dated as it is, Da' Grump's book mentioned that there needed to be at least some small amount of pressure getting past the top ring to help the second ring do its job controlling excess oil on the cylinder wall. If this is true, then a zero-leakage top ring is going to make it harder to deal with that oil... which sounds very much like the complaints.

[modok]

Some companies, Deviss for one, make ring sets with a wave spring behind the second ring.

[GARY C]

I don't understand the question. Gapless rings are compatible with gas ports. The engine I mentioned a few posts back has lateral ones in addition to the gapless rings.

I'm just trying to understand the fuss. I suspect any issues from a gapless ring revolve around the induction stroke more than the compression/combustion stroke.

Dated as it is, Da' Grump's book mentioned that there needed to be at least some small amount of pressure getting past the top ring to help the second ring do its job controlling excess oil on the cylinder wall. If this is true, then a zero-leakage top ring is going to make it harder to deal with that oil... which sounds very much like the complaints.

One counter argument to that would be the many race winning engines built leaving the second ring out altogether with no blow by issues and some feel the dyno results have shown the power gains worth the risk.

[MadBill]

The engine I referenced above used lateral gas-ported 2 ring NOS Roush pistons with medium tension oil rings and 14" H2O pan vacuum. At assembly, the rotational torque was 6-7 lb-ft.

[ProPower engines]

I see guys choose the wrong ring material for the application lots and even the gapless top ring has material
options but guys look at cost and shy away from them and go to the gapless 2nd ring \just because of cost. if the pistons have an accumulator groove between the top rings that help the top seal better.
That and gas ports 2 options that are extra cost and guys just do not get what the benefits are they just see
dollar signs and their buddy never used them.

The gapless 2nd rings can be really deceiving as to engine condition also.
While the rings will give the impression of a good leak down test of @-3% at most when you blow the top ring land off
it don't make the engine condition great but the leak test says its mint.

Just took a late model hemi apart yesterday with 5 pistons damaged and burnt the top ring lands out but the 2nd ring said
it was fine..............till the plug check revealed melted aluminum all over the plugs on 5 holes.

So much for the great leak test

[GARY C]

The engine I referenced above used lateral gas-ported 2 ring NOS Roush pistons with medium tension oil rings and 14" H2O pan vacuum. At assembly, the rotational torque was 6-7 lb-ft.

My comment was in regards to Grumpys thought on the importance of a 2nd ring to control oil, I think the consensus is that they do but many have shown that they are not always necessary and in some cases reduce power.

Has anyone ever tried a gapless top ring without a second ring?

How many ring issues have been caused by the pressure in between the top and the second ring that was been blamed on either the bad top or a bad second ring but was actually caused by both?

[BradH]

I'm just trying to understand the fuss. I suspect any issues from a gapless ring revolve around the induction stroke more than the compression/combustion stroke.

Dated as it is, Da' Grump's book mentioned that there needed to be at least some small amount of pressure getting past the top ring to help the second ring do its job controlling excess oil on the cylinder wall. If this is true, then a zero-leakage top ring is going to make it harder to deal with that oil... which sounds very much like the complaints.

One counter argument to that would be the many race winning engines built leaving the second ring out altogether with no blow by issues and some feel the dyno results have shown the power gains worth the risk.

Fair assumption that the engines running that type of ring config use vacuum pumps? Could be an indication that gapless top rings ought to be used with a vacuum pump, even with a 2nd ring.

If you can't blow it down from the top, suck it down from the bottom...

[PRH]

Tried the TS gapless top ring in my friends Stocker. They are a two piece ring.

Zero extra power....... but no less either.

After one season of use........ pulled the pistons out....... the gaps for the two pieces had moved until the gaps were lined up(all 8 pistons)....... not gapless anymore.

Went back to the normal rings.

[MadBill]

The engine I referenced above used lateral gas-ported 2 ring NOS Roush pistons with medium tension oil rings and 14" H2O pan vacuum. At assembly, the rotational torque was 6-7 lb-ft.

...
Has anyone ever tried a gapless top ring without a second ring? ...

Yes. Earlier in this thread I mentioned this engine because it runs gapless rings: "The Gapless set I specced for a 680 HP 8,000 RPM 380" SBF road racer now has ~ 40 hrs. on it and after a valve touch-up the worst leakdown was 2%. I find that reassuring..."

[Alaskaracer]

I take leak down numbers and cranking compression with a grain of salt. Just because an engine has good numbers here when testing, it's a completely different ball game under running conditions. I've seen engines with great leak down numbers and good cranking compression run like total crap....and vice versa......While good tools to use, they don't tell the whole story....

Just because an engine shows good numbers when it's static doesn't mean it's sealing well when running......

Gapless have their place, I'll agree on that, but they are not better than a conventional ring. As to running alky and having it dilute the oil, that's a tuning issue, not a ring issue...and a different set of rings won't fix that.