Gapless rings
 

What are your thoughts on gapless rings. I've never used them but have only read good things in various automotive magazines. My engine builder doesn't want to use them and wouldn't really get into why not. 4.5 bore, JE pistons, 8.8-1 comp.

Re: Gapless rings
 

I have used them on blower motors with good results.

Re: Gapless rings
 

By the way, I did a search on this and got some results, but all seemed to be over a year old. Thought there might be some new opinions.

Re: Gapless rings
 

My race engine builder friend says that they are great if you tear down between races, but will carbon up and stick as time goes bye. A little ring gap keeps the rings clean by allowing some gases to blow by the rings during combustion.

Re: Gapless rings
 

My machinist does not like to use them because he had a few that broke where the ends overlap. However, these are usually high reving race engines, 7,000 rpm plus. He says rpm's were most likely the cause. :chimp:

Re: Gapless rings
 

I have used them for race engines. I didnt have good luck with them. They just dont seem to last long. I would not use them in a boat engine.

Re: Gapless rings
 

I have tried gapless rings on several 540 engine combos,they worked ok but seemed to loose there seal sooner than conventional rings.I like using JE/speedpro rings with std tension oil rings .Great seal and long life.

Re: Gapless rings
 

Consensus seems to be to stay away from gapless rings.

Re: Gapless rings
 

I am running them in my procharged 540,ran them in same 540 before freshening it this time too for 130 hours with good results. Leakdown was under 10 % at 100 hours last time,not sure how long they really could last though. Some engine builders hate them,never personally seen why though. There have been different designs and positions they been run in over the years too,maybe some earlier ones were problematic and got bad rep.I do know that my 502 w std moly faced rings (with extra clearence for the supercharger) had 6-9% leakdown after dynoing compared to less than 3% with the gapless and 30-50 % leakdown at 175-180 hours running 6-8 psi boost and that wasn't with the 502 pistons with the problematic metric rings either,Smitty

Re: Gapless rings
 

Maybe it's just me, but the cylinder walls seem to get glazed a lot quicker with the gapless rings. I'm not sure if it's because of the material, or the design, but I did notice that glazing is a problem at the higher RPMs on a lot of engines that use them.

The leakdown is only slightly better than a properly clearanced set of standard rings, so I just use the regular rings. I think the only time gapless rings would be best is with high boost applications where blow-by is a big problem.

- Paul