great information- thanks guys- don't think I need to spen that much on so little. Maybe next build.

 

The only reason I am going with them is I got them real cheap. I can't see the money they want for them in the catalogs.

As far as gas pressure and sealing the rings. I can see problems with 2nd ring sealing if the gapless units are used for the top ring. The gapless ring itself will seal well, even better than a standard ring. Gas pressure will push the ring down in the land just like a regular ring. Gas pressure will also force the ring outwards against the wall just like a regular ring. So where is the difference?

I can not see them causing uneven scraping, at least any more uneven than a standard ring. I can even see them doing a better job.

I can not see them causing any more ring land wear than a normal ring. I can see them causing less wear because of fewer corrosive and abrasive deposits in the ring land area.

As far as detonation, what oil contamination, what exhaust gas contamination???

As far as the dyno test. Weren't both sets of rings operating under the same conditions with a tapered bore etc? Were both sets of rings allowed to seat in? If not were they both operating without seating in?

Remember a manufacturer Like Federal Mogul would have to engineer and market their own rings that were significantly different in design from existing rings -OR- they would have to pay big royalties to use an existing design. In many instances it is not economically feasible to do either. In those cases since they can not compete sometimes it is easier and more cost effective to just try to run down or badmouth the competing product.

 

they report that they have engineered the top ring to alleviate problems with the second ring sealing...all above my comprehension at this point but it obviously was something they had to overcome in making the top ring gapless. I'm not giving it up due to worry about their product as i trust them as much a anyone...but cost is huge at this point and return isn't appearing to justify it. Good thread though- informative etc.

 

Hey Eric,

When the article was written, the gapless top ring wasn't yet offered, & if so, KB might have had different opinions. Dunno. The gapless top is only offered on the TS Max Seal sets, not on the other TS sets, so it's the old story of "you pays yer money, you takes yer choice." So, the article must be "read" from the point of using a gapless 2nd ring only.

What they are getting at is that some combustion pressure is "trapped" momentarily between rings, (regardless of what is happening on the chamber side & crankcase side at that moment in the process) causing uneven loads on each side of the rings & thus the flutter. With conventional sets and some dimension of gap, the pressures at the various times are more predictable, & evened out (not exactly the term, but I can't think of a better way to put it). This trapped exhaust gas, which takes a certain longer period of time to escape from between the 1st & 2nd rings (because there is no crankcase pressure to help expel (push) it, or crankcase vacuum to pull it) is what causes charge contamination on the intake stroke. The flutter is what leads to the poor seal, uneven scraping, & increased land wear. If you assume flutter, that leads to the oil contamination. Putting the gapless ring issue aside, I guarantee ring flutter causes these problems- I've built too many drag engines & torn too many down not to recognize the causes/effects of flutter. Not trying to brag in any way, just saying I've seen it. Street builds are a different story and I think the jury is still out on that one. In their testing as a piston mfg., they say they've seen ring flutter, even in test "street" engines directly attributable to the gapless design (again, on the 2nd ring only). If the flutter (assumed or real) is taken out of the equation, then the drawbacks, perceived or real, are mostly gone too, with the exception of the charge contamination.

I should note, before you shoot the messenger, that this is KB's point of view, as best as I can relate it, & not necessarily mine, although as I mentioned I personally have not really seen a difference in the stuff I've been involved with, & hard to justify the cost. On the street I think it would be tough to see much of a negative (if there is one) performance difference, or positive, & I certainly wouldn't refuse to use them on someone's street engine- just not my choice. It makes sense to me that the Max Seal sets would tend to lessen the problem.

As far as the dyno test: I'd have to dig it up- it strikes me that they did do something different for the gapless set, which was tested last & intended to be the final set used. IIRC they used a Sunnen machine hone instead of the hand hone used for the std. set. But, assuming that they didn't do anything differently, the big difference to me is that the std. set was a basic set with preset gaps, which, when they installed them, were extremely wide (unusable IMHO), while the gapless had file-fit tops & of course the gapless 2nd. Under those circumstances, the tighter gaps are going to have a better seal. What I was trying to get at, evidently without success, , was that the one test I've seen was meaningless at least to me. Believe me, if I thought it was a fair test & pointed out a true way to gain power, I'd be on it like a rat on cheese. And it may be a way- I just don't think that this particular test proved it one way or the other.

I don't want to say too much about the Federal Mogul test because I don't want to get a particular person into any hot water. If you are interested you can PM me & I'll try to fill in. Suffice it to say that the person who related their findings worked there and was involved in the testing; he no longer works there and probably has no particular axe to grind. If anything, since his position was eliminated due to cutting costs & he was out of a job after ten plus years, he might have a few negatives to say about them. At any rate, his comments on the gapless rings were made after he left. He no longer works there, but is now in a business that involves the aftermarket; whether this would cause any problems for him I don't know, but I'd rather not be the cause of anything. His comments were stronger than what I said, but you get the gist of it.

However, as a rule, I'd agree with what you said about manufacturers, competitors, products, & economics. In this particular case I think he was telling the truth, but as always it can be taken with a grain of salt if you like.

Like I said, all this is certainly debatable. Most of us, me included, prolly don't have the $$ to do a true comparison. If ya got 'em cheap, go for it, I say.

 

I can agree that with a gapless second ring the pressure between the rings would only release about half as fast as with gaps at "both" ends of the volume between the rings and ALL the gas in that volume would escape into the combustion chamber instead of half into the crankcase. That wouldn't amount to a whole lot of gas, hopefully because it does not have a whole lot more pressure than the residual gas pressure in the cylinder at the bottom of the exhaust stroke. Which can be quite high...

Would a slightly larger top ring gap help any with that flutter/gas problem? With a gapless 2nd ring the top ring gap is not as important.

BTW- I have seen many unfair and poorly conducted "comparison tests" done. Some of them with the best of intentions and many more with the worst of intentions. We won't even count the Tornado and late night infomercial tests, but some of the tests published in many magazines are just as bad.

 

The recommendation nowadays in the racing side is less gap on top ring than bottom, (more gap on bottom so pressure won't build up & cause the flutter).

 

With zero gap on the lower ring it might be better to go the other way and increase the gap on the upper ring.

 

I don't recall whether they did any testing with the gaps. I think that TS does, or did at any rate, recommend larger top gaps with the "Street" & "Race" sets.

Eric...ya....ya don't mean that magazines...slant results to please the advertisers? Say it ain't so!

I bet next you'll tell me there's no Easter Bunny. Somebody already told me there ain't no Santy Claus, but I'm not buying it. Some fat dude passes out on my lawn every Christmas.

 

if you live in Montana that fat man would be me...not santa

 

You wouldn't believe the number of people that think anything printed in a magazine is the gospel truth, -and some of them... -they POST here!!!

Even more seem to believe everything on TV!!!