Don Terrill’s Speed-Talk

we used to pull the pin out of the groove and use them no problems

I like the gapless top rings, and napier second ring, never had any issues. My last engine had 600 passes on it and still leaked at 0 percent, I know this is only a test pressure reading, but compared to normal rings with that many runs I normally seen 30% leak. Now as far as flutter goes a gapless second ring will make something happen to a top ring, seen it on my engine, the cylinder actually had two ring groove marks one for top and one for second and it lost a little ET on the track. I assumed it was ring flutter under load.

Yes, a gapless second ring flies in the face of current science...

For me, the gapless rings are a solution to a non existent problem.

Coloradoracer wrote: ↑Mon Apr 29, 2019 8:54 pm Contrary to what you may read or have been told, gapless rings will not net you gains like you expect. They have a tendency to "flutter" which affects ring seal. No, Matt Hartford (total seal VP) doesn't run them in his pro stock either. Many dyno tests have proven they don't work as well as led to believe. I ran the gapless top in my stuff and had oil issues in the chamber. No matter what I did I'd get oil where it shouldn't be. Switched to conventional rings and no more issues. Nitrous DOES NOT like oil in the chambers, it will detonate. Most top builders don't use them and you won't see them in any pro stock. If they worked that well you would. Best ring pack is a ductile top, napier second. Thinner is better and lower tension to a point. You'd be surprised how much you can open a gap on a top ring before it starts to affect power.

Thanks, this is exactly the input I was looking for! Great info!!!

MadBill wrote: ↑Mon Apr 29, 2019 10:52 pm As we know this cuts both ways, but David Vizard is a fan of Gapless top rings.

Ok here is more good info just what I was looking for!!!

tenxal wrote: ↑Tue Apr 30, 2019 9:49 am For me, the gapless rings are a solution to a non existent problem.

HHHHMMMM thanks to all for the input! Food for thought indeed!

How do these rings work for a DD? I had the choice and went with conventional.

For me, the gapless rings are a solution to a non existent problem. (quote) I agree with this, but did use them in a blown app. with success.

ClassAct wrote: ↑Mon Apr 29, 2019 10:42 pm Ok. Sounds like BS to me. I've dyno tested them MANY times, never had an oil user, never seen the flutter. Like anything else, the better the block, the better the bore finish, the better the finish and fit of the ring in the groove, the better the deal. An OE block like the GM 400 will respond to a gapless top ring and show much more improvement in power and blow by under load than say a quality aftermarket block.

IMO, it's nearly impossible to get rings that don't seal anymore. If you have oil use issues with ANY ring, get a good long look in the mirror.

Sorry to burst your bubble, but the only rings I've ever had issues with were the gapless. Changed rings, no issues. And to my original point, if they are so good, then why does Matt and EVERY OTHER pro stock builder out there not run them? Won't find them in comp eliminator either, super stock, mountain motors, nascar cup engines, F1, or any other similar application? I don't know of any top engine builder that uses them.... Novafornow said it well, perfect solution to a non-existent problem. If you're finding gains using them on your stuff, then I'd be looking at what you're doing wrong instead of what someone else isn't....

Not my intent to start an argument but just because you have good luck with them doesn't mean they work for everyone.

I had bad luck with them, excessive oil passing into combustion. Buddy said he was gonna use them, I told him of my experience, but he tried them as well. Same outcome. You can dismiss our anecdotal experiences, but I believe they have higher odds of not sealing compared to conventional rings.

" Won't find them in comp eliminator either, super stock, mountain motors, nascar cup engines, F1, or any other similar application? I don't know of any top engine builder that uses them.... Novafornow said it well, perfect solution to a non-existent problem. If you're finding gains using them on your stuff, then I'd be looking at what you're doing wrong instead of what someone else isn't...."

I have built thousands of racing engines and never used a gapless ring, just never saw the need. That being said, I doubt if they would hurt anything in most applications.

And as stated above, I have been is several NASCAR Cup shops and never seen them using any type of gapless.

Coloradoracer wrote: ↑Tue Apr 30, 2019 7:36 pm

ClassAct wrote: ↑Mon Apr 29, 2019 10:42 pm Ok. Sounds like BS to me. I've dyno tested them MANY times, never had an oil user, never seen the flutter. Like anything else, the better the block, the better the bore finish, the better the finish and fit of the ring in the groove, the better the deal. An OE block like the GM 400 will respond to a gapless top ring and show much more improvement in power and blow by under load than say a quality aftermarket block.

IMO, it's nearly impossible to get rings that don't seal anymore. If you have oil use issues with ANY ring, get a good long look in the mirror.

Sorry to burst your bubble, but the only rings I've ever had issues with were the gapless. Changed rings, no issues. And to my original point, if they are so good, then why does Matt and EVERY OTHER pro stock builder out there not run them? Won't find them in comp eliminator either, super stock, mountain motors, nascar cup engines, F1, or any other similar application? I don't know of any top engine builder that uses them.... Novafornow said it well, perfect solution to a non-existent problem. If you're finding gains using them on your stuff, then I'd be looking at what you're doing wrong instead of what someone else isn't....

Not my intent to start an argument but just because you have good luck with them doesn't mean they work for everyone.

Just because you used them and can't make them work doesn't mean they don't work. I've tested them. Many times. It's not my intent to start an argument either. Just stating the truth of what I've done. I really don't care what any of the above do. If you can't make a ring seal, that's on whoever finished the bores.

You aren't talking about a power increase. You say the rings don't seal. That's just silly.

In 40 years of farting with pistons for a living, I have come with exactly one reason to not avoid selling a set of Gapless, or Zero-Gap rings. That is I make more money on them than I do most conventional ring sets. So I stopped arguing about it decades ago.

I will say that we once had a motor that leaked 7% at the beginning of the season and it ran 8.50s. At the end of the season one cylinder leaked 70%....and it ran 8.50s.

I was also told (Zero-Gap) that, if you left the boot out from behind the ring, that "statically, it would leak the same as a Speed-Pro. Dynamically, it would make no difference at all" That told me that the ring didn't do what people supposed it did, and they were well aware of it.

That was my employer at C&A, assuming you care.

My guess is big gaps do not matter at extreme RPM, or with a blower or heavy uses of nitrous, and long term wear is not a factor.
But at lower rpms, or wanting many hours or miles of wear, then gapless does matter, as does big ring gaps. Gapless in the top ring grooves seems to work better, and it was its original suggest position way back in the time machine, but detonation would mess them up. So they started using and suggest the second groove. That caused a blow-by oil problem in the second groove, in many engines.

Today the ring material is suppose to be stronger, in them, and many suggest it works once again best in the top grooves. I used them many decades ago in the second groove on my street machine, and still have not lost any measurable cranking compression, after all these decades and 10s of thousands of miles, and perhaps close to 100,000 street miles with TRW forged pistons.