360 rings. gapless?

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mopar_1974

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ok....so i have decided to get the kb107's for my 360. now its time to choose rings. Are the gapless rings worth the money? i found one that isnt too bad of a price but it is rated for street/stock. I plan on having about 350-400 hp by the time i'm done. they cannot be used for over 10.5 - 1 compression. the kb's should be under 10-1 i beleive. can anyone confirm this?

here is a link of the first rings i am looking at

http://store.summitracing.com/partd...3+4294908395+4294871792+4294890188+4294871735

second...racing

http://store.summitracing.com/partd...908395+4294890187+4294903870+115&autoview=sku

or...would i be better off spending the money and buying these? they would be nice, but i dont think they are worth the extra $130

http://store.summitracing.com/partd...871792+4294890188+4294871735+115&autoview=sku

or am i wasting money and just get some good sealed power rings?

http://store.summitracing.com/partdetail.asp?part=SLP-R9903030

thanks for your help. i think the second ones would be my best bet, but i am looking for ANY advice and tips other mopar gurus have.
 
I have never used the gapless rings but from what I have read they are only useful if you are trying to squeeze the last couple of HP out of an engine. Certainly don't need them if your goal is 350-400HP. I am using Sealed Power Moly rings in my engine.

What you wind up for compression with the KB107's is totally a function of what machining you have done to the block, what heads and what machining you have done to the heads. I have KB107's in my 360 and the block is machined for zero deck and I have magnum heads with 64cc chambers. With a Fel-Pro head gasket that has a 4.180 bore and a compressed thickness of 0.039 I have 10.6:1 compression.
 
Be sure to watch the end gaps on those KB pistons! I would use a good file to fit ring set & gap them per the KB spec. If you don't, you will end up with some broken top comp rings. As far as the gapless rings being used with the KB's, I haver never done that. You should check with the pistom mfg for their recommendations.
 
The gapless rings are a good purchase IMO, but not a must have. They will decrease blow by and air/fuel sepage into the oil. So right there, it's a win win. They will also create more vacuum. For the extra cash spent, I say it is money well spent, not just spent.
Again, there not a must have but would be a nice addition. It is a little thing. Do a few little things and you can start adding it up to something more than just an added trick or 2.
 
Before you buy gapless rings, I'd contact KB and ask them about using gapless rings on their pistons. KB pistons are very touchy as far as ring gap goes, so before you shell out the cash for the rings find out if KB says its ok to use them.
 
For the level you want, simple Speed Pro moly file-to-fit are fine. What they said on teh gaps...Get it right or pay the price...lol. Gapless behave no different than std rings, you still set the gaps, you just want to be careful installing them. I think they are overrated really.
 
Gapless behave no different than std rings, you still set the gaps,
Click to expand...
The top rings have no gaps,
2nd ring has gap
3rd ring oil

For the level you want, simple Speed Pro moly file-to-fit are fine.
Click to expand...
Absoultely true. I want to be clear on that point like Moper said.

And what Duster Don said. Call KB. It can not hurt.
 
rumblefish360 said:
The top rings have no gaps,
.
Click to expand...

Sure they do! It's just that there is an insert that also has a gap, but when you install them with the gaps opposite each other they are covered.

You still have to make sure that the gap on the ring and the insert meet KB's requirements or you will have the ends crashing into each other and either breaking the ring or the piston land.

FYI, even though the KB's spec a larger gap when installing the rings the gap winds up being the same as on another piston when everything is up to operating temperatures so the seal is the same.
 
Ahhhhhhh, and in what I wrote is the secrect. I did say rings.
Your description is dead balls on correct.
Now wheres that damn site. I was there a little while ago and they showed there rings and how they work.
 
I installed gapless rings on my 340 and the set I used had the top ring gapped and the second ring was gapless. The gapless ring was a thinner ring with a shoulder on the inside and a second ring that looked like a oil ring that fit around it. The most important thing is to make sure the top ring has the correct gap per Keith Black web site tech info. Thats were most of the heat is at. Bore x .0065= gap size for the top ring, with a street engine and a carb. Nitrous and forced induction require bigger gaps. No wider gapping of the second ring is required.
If you use gapples rings you have to close down the pcv hose to around a 1/16 of an inch. As you will have almost no blowby or compression loss and the pcv will suck the oil out of the valve cover. Plus your oil will stay cleaner a lot longer.
Is it worth it, thats a toss up. I thought it was but everyone has a different opinion. Bob
 
That's backwards. Who's ring set was this? The top ring is the compression ring. The second ring's main function is scraping oil away. It doesnt do much to hold in pressure. In fact, many builders now set the second ring gap slightly larger than the top ring, because if gasses build up in between the rings, the top ring's sealing ability is compromized. Smokey Yunick knew about this in the 70s...
 
Its a Total Seal 5/64 ring set and its used for street engines. The top ring gapless set is usually 1/16 and made for race engines.
 
I see what they did. I still can't believe it's good for things to be that way. You can see the taper they show on their website for the 2nd ring. In all ring sets regardless of brand, the top ring has rounded edges. It glides better over the wall, and seals better longer. The second ring has the edge, that scrapes excess oil the main oil rings dont get off the walls on the downstroke, because the rounded edges don't seal out oil well. The problem is, the gasses that get between those two rings as rpm rises unseats the top ring from the ring groove, and that looses pressure. The gapless design top rings works. I usually run the Childs and Albert, but same same. A gapless 2nd is asking for sealing problems in anything over about 4K rpm and any mileage past 8-10K... At least no engineering/design I'm aware of says sealing off the 2nd ring helps compression. Total Seal is either WAY ahead of the curve (which would mean everyone and their brother would be using them) or they are selling the 2nd ring equivlent of Splitfire plugs. They will work for some, for a while.
 
Moper, you are right about the second ring. New R&D clearly shows that a wider gapped second ring improves top ring seal..and performance. Some of the ring manufacturers are now listing this in the instruction sheets provided in the ring pack. Something us racers knew about for a few years now. Very goos point there Moper. Terry.
 
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