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Ring Preperation

Posted: Fri Apr 15, 2005 9:02 pm
by Trev
Hi Everyone
Has anyone read this article
If so what do u think of him sanding the rings
I have only ever gapped them and installed as is.
Trev


http://www.circletrack.com/howto/4639/

Posted: Sat Apr 16, 2005 6:22 pm
by ADR
Trev
A lot of what he says is probably good advice, I don't know about the 400 grit that sounds a little course to me and I had to chuckle at the comment about the feeler gauge growing from holding on to it too long.
Even if you raised the temp of that feeler guage by 50 degrees you or I wouldn't be able to measure the difference in thickness. Maybe what he means is the piston is growing from holding onto it too long cause it sure as heck aint the feeler stock. :D
Dale

Posted: Tue Apr 19, 2005 8:58 am
by d4490
THe ONLY thing I would do is gap the rings. I work for one of the larger piston ring manufacurers, and some of the brilliant minds at here have agreed that sanding the ring will remove the shapes that we have worked hard at to perfect.

Taking an expander ring and bending the end tang to get a feel as desribed in this article is totally wrong, unless you want to increase the tension on the ring. The expander is basicly a spring the forces the rails onto the cylinder walls, by bending the ends of the expander, you are increasing the springs length, thus inscreasing the spring force generated by the expander. This will increase the tension on your rings. This all depends on what the tension of the ring is before you bend the ends. It is possible to take a LOW TENSION ring pack, bend the ends, and end up with more tension than a NORMAL TENSION ring.

When you get your rings from what ever manufacurer you select, I would wash them with mineral spirits, gap them to the recommended specifications to your engine, and run them. Do not break the edges around the I.D., or the O.D. of the ring. They are left sharp for a reason. Your second ring has a small taper ground on the face of the ring, this will help scrape oil off the cylinder wall (piston moving down in cylinder) that the oil rings have missed, and still seal of the combustion gasses (piston moving up in cylinder) the the top ring has missed.

Posted: Tue Apr 19, 2005 9:11 am
by ChrisU
Actually if you bend the tabs in the opposite direction of what you are describing would that not decrease tension? You lost me on that one as I've been decreasing tension that way for a long time... and have a scale to prove it.

Also I have serious issues with using the second ring for compression, and I believe that's a big mistake. Just my .02 is all.

Chris

Posted: Tue Apr 19, 2005 9:55 am
by d4490
Chris,

If you bend the ends of the ring away from the gap, you will decrease the tension. We have done this on experiments, and we have measured as much as 2.5 lbs of tension decrease on a normally 10 lb tension ring. Yes we do have scales that measure the tension on the ring.

As for the second ring as a compression ring, that is not what I was trying to imply. The top ring controls majority of the compression, the second ring will help the compression ring with the left over gasses that sneak by the compression ring as well as help control the oil consumption. The second rings duties are split by compression and oil control. The top rings main job is to control the compression gasses, with very little oil control. Top rings have a flat face or are ground to have a barrel face. Top rings are usualy filled with some type of moly, or are chromed, and the main material can be steel, ductile or cast iron. The second rings are mainly cast iron with a tapered face to them. There are other shapes and materials that are used, but for the majority of the racing/aftermarket rings being sold uses these. We currently have over 20 dyno cells running 8-10 hours a day on testing rings for the OEM. Alot of our testing helps the aftermarket rings as well. We supply piston rings to alot of the top engine builder in racing, and one team in NASCAR uses our rings in all their engines, they won the Daytona 500 and many championships with them. We spend counltess hjours testing and developing our pistong rings.

Posted: Tue Apr 19, 2005 10:19 am
by onovakind67
I wonder how many large ring manufacturers are in Muskegon?

Posted: Tue Apr 19, 2005 11:10 am
by d4490
In the surrounding area, there are a few piston ring manufacurers, Hastings, Federal Mogul (Sealed Power), and Dana (Perfect Circle).

Posted: Tue Apr 19, 2005 12:14 pm
by ChrisU
D4490,

Have you done any development work with ring coatings and alternative ring face coatings?

Posted: Tue Apr 19, 2005 12:57 pm
by d4490
Chris,

Our design and chemical engineers are always looking at better coatings, ring face shape, and ring materials to deliver a better ring. Most of this development goes into OEM rings, but it doues trickle over to the aftermarket rings. We offer different side coating to minimize the ring welding to the piston, and different face coatings/barrel shapes for our ring packages.

My position here is the tool engineer. I design and develop the cutting tools that are used to process the piston rings. I work closely with the piston ring design engineers and the R&D engineers with new tooling.

If you have any specific questions pertaining to piston rings, i am sure I can find the right person to answer them.

Cool

Posted: Thu Apr 21, 2005 7:04 am
by Trev
Thanks Guys
I will do what i normally do
Wash them in Kero and then Gap them.

While we are on the subject I want to give my ten cents worth on ring gaps

Say I gap the top ring for a given application and it is 16 thou

If you take that 16 thou as a percentage of the bore size of 4 inches

Then its suff all

Say i then gap the ring to 26 thou and take it as a percentage of the 4 inch bore

Its still stuff all.

Are the gaps really that critical
Trev

Posted: Fri Apr 22, 2005 12:06 am
by ClassKing
D4490:
Same question put differently - What is your companies acceptable tolerance of ring end gap? Say, just naturally aspirated.

Thanks.

Hi

Posted: Fri Apr 22, 2005 4:44 am
by Trev
Hi Classking
maybe u didnt communicate my ideas well enuff

I was trying to explain that i think these ring gaps we use maybe a load of rubbish
If u gap the ring at 16 thou like recommended and then u did a different ring to 40 thou then i wouldnt be surprised if you couldnet tell the difference

Only reason im saying this is that as a percentage of overall all ring contact area, the diffence between say 16 thou and 40 thou is nothing.

So theorectically you wouldnt be able to measure any difference in performance.

Trev

Posted: Fri Apr 22, 2005 12:15 pm
by d4490
I have heard of test done here that with different gaps, from .016 to .030, in a 4.000 bore, no measurable power differences and no measurable oil consumption difference were found. I do not believe we have tested any of the "ZERO GAP" rings, so I can not give any data on those style of rings. Most ring gaps that are advertised are recommended minimums.

Posted: Fri Apr 22, 2005 12:49 pm
by ClassKing
Thanks. That's what I was taught at Chaffey, but that was 15 years ago, and I know ring tech has changed quite a bit. Over the year either myself or an employee has made mistakes with the electronic gapping tool, and I have a couple of top rings that are .030 gapped. I've been leary about using them. Maybe I'll try them now......