are there any known drawbacks to using gapless rings- top ring to be exact- talked to the folks at total seal and they think it's applicable to my application- boost torque a little bit. I know they are expensive- mabe too much so.

anyone know the width I need with badger pistons off hand (yea I searched...)

Any probs with vacuum etc? thanks

 

I don't think for the expense they're worth it, you won't feel the difference, especially on the street.

 

The only problems I have heard about were when people used the wrong oil control rings.

 

like not stiff enough?.

 

People have purchased the low tension oil rings that are intended for racing which results in excessive oil consumption for a daily driver.

I would think the gapless rings would work better at higher altitudes and with forced induction.

I have a set with the gapless second ring and standard oil rings that I picked up for $20 off ebay all in the original packaging.

The Ertel 1282P pistons I have use 5/64" compression and 3/16" oil rings. I have no idea what the newer pistons use.

 

right- couldn't bring the word 'tension' to my fingers...mind blockI heard that most newer engines use lower tension in stock builds?

 

The OEMs may be tweaking the tension to reduce the friction as much as possible. The low tension rings from Total Seal are not the same tho, -at least not the last time I talked to them.

 

right...I was researching rings and oems are tweaking as you stated to lower friction. Total Seal did come out with the gapless top ring - used to only be middle I guess. They said the top ring would work for my application and i'd see a small increase in torque. Other than that the benefit appears to be significant in the high performance engines- like 35hp or so.

My build both is and isn't high performance. With the roller cam and high dynamic compression it is similar- the main difference is the cam which is 212-218 hardly lopey. But with around 8.75 DCR I'm thinking there might be something half way significant in it for me. I guess it comes down to why they are more effective and what role compression plays in that.

 

The low tension rings used in racing require vacuum in the crankcase. Most guys run a vacuum pump. Like Torque1st said, it would result in oil use otherwise. Also trend is to thinner ring packages for less friction.

 

i won't use low compression rings...not even interested.

 

???? -Sorry, what do you mean here?

 

I'm sure he meant low tension.

 

yea...what rancheroracer said...whew!

 

I don't even use low tension oil rings on my race engines like Eric said they are only good if your going to run a vac pump other than that not a good idea.

 

Roger,

There used to be a pretty good article on the KB/Silvolite website about gapless rings ("and why they hate them" ). I couldn't find it last time I looked, unfortunately- it went into a great deal of detail about the pros & cons. Maybe they got sued or something.

The points of the article are this: one, because of the lack of gaps, exhaust gas/combustion pressure tends to "unload" the top & second rings, leading to poor ring seal during operation. They show great leakdown results, but they don't hold up when running. A vacuum pump tends to "crutch" the situation, but not cure it per se.

Item two is that, apparently, they can cause oil control problems due to uneven scraping by the second ring.

Item three is that they can cause the piston ring lands to wear, causing...poor ring seal.

Number four: possible detonation due to the A) poor oil control &/or B) exhaust gas contaminating the charge.


Now, this is all pretty debatable one way or t'other, & some people swear by them (of course, after you've chucked out $$$ for anything, you WANT to believe in it! ).

The one dyno test that did a "back to back" comparison showed around 7-8 hp with gapless rings- but they admitted the conventional rings weren't given much of a chance (tapered bore, hand hone, preset gaps, etc.) so I don't put much stock in it.

The only other thing I can add is that Federal Mogul (Speed Pro,etc.) looked at/tested them for several years (after all, since it's competition, it's in their best interest to try to emulate it), and, after everything was said & done, felt that gapless rings were not what they are claimed to be.

In teardowns with gapless rings, I've not personally seen much advantage or disadvantage on roundy-round or drag engines. I prefer the good Speed-Pro sets (the R series, starting around $95 & up) as opposed to anything else, & so far as I know, most of the big custom piston makers like Ross, J&E, Diamond, etc. sell them in repackaged form as their "custom" sets. My $.03.