Gapless rings?

56taskforce

Well-known member
Mar 30, 2014
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I have never used them but have seen many good things about them in the gasser world. So far only seen them offered by Scott at SDP for Duramax. Anyone use them and what's your results???
 

56taskforce

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Mar 30, 2014
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I use them in my Arais pistons. Zero issues with them.


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Any notable benefits? Most piston sets come with rings haven't seen any sets offering gapless do you think it's worth replacing the ring that come with the piston set?
 

S Phinney

Active member
Aug 15, 2008
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Quncy, Fl
Any notable benefits? Most piston sets come with rings haven't seen any sets offering gapless do you think it's worth replacing the ring that come with the piston set?

I haven’t had any issues with either. With forged you run a lot of end gap so I opted for gapless in hopes of helping the set last longer. In my opinion I think bore finish and installer error are your two biggest problems. They will help seal it up a little more.


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Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Phoenix Az
Are the gapless a stainless steel or different type? Never got a chance to play with a set... yet lol
 

56taskforce

Well-known member
Mar 30, 2014
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Thanks guys. What bore finish are they wanting? I am starting with a brand new LML block and the bored seem to have pretty light hone in my opinion.
 

S Phinney

Active member
Aug 15, 2008
4,011
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Quncy, Fl
Seal power is the manufacturer of the ones that I used. Their technical department is very good at Hong you appropriate information. You would have to measure all the roughness specs with a Profilometer. Very few shops have this advanced tool. The good news is experienced machinists and the newer equipment they would use is pretty good. Using stones for bore finish usually is a 325 stone. Using diamond stones doesn’t really have a comparison type number. But I believe the stone number was a 55 stone if I remember right. O I’ve had shops use both. I personally feel the stone finished notes sealed quicker than the diamond finished bores. Plateau honing is a must have I good finishes.


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kidturbo

Piston Tester
Jul 21, 2010
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Somewhere On The Ohio
www.marinemods.us
Agree the diamond hone finish is overrated, but if brand new block, likely the finish your seeing.

Many years ago I waited for several months to get an LLY block bored by a shop that had a diamond hone as book called for. When finally picked it up, ask the tech to see this special hone. He says; "What diamond hone? I used the same hone I use on every other block." That was the last time I every thought about one...
 

Hagemann

New member
Sep 30, 2011
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Tyrone, Georgia
Duramax really needs a diamond hone setup because of the induction hardening. The stones break down too quickly to keep cylinders square. Not many machinist understand all that goes on to make a perfect cylinder. You need a course grit to create a square cylinder and provide deep enough scratches to hold oil, the you knock the peeks of the scratches off to provide a smooth surface for the rings all while maintaining a cross hatch at the correct angle. Plateau hone is the final step to knock off the rough edges, like stropping a knife on leather. The gapless ring is usually on the second ring, it uses the standard ring that has had a step machined for the scraper ring off the oil control ring. You simply stagger the gaps. I think the gapless would help with cold starts and a vehicle that sees a lot of idling to keep oil cleaner. For performance, I don’t think as much. Good cylinder finish with a torque plate during honing should be good.
 
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