Anodized Ring Lands

[Larry Hill]

Anybody have any experience or used such? My top ring to land ware pattern is lacking making 360* contact. 2nd ring without anodizing on land has nice ware pattern as if it was a top ring. It looks like the top ring is allowing a lot of cylinder pressure to get to the second ring. Both are steel rings. I will lap top ring on surface plate to check for flatness.

[Ralph A Powell]

Hard anodizing if done correctly is good.You may not have enough radial tension and the ring is not sealing to bore if cylinder pressure rises very quick! Have you ever run Engine with a Blowby meter?


W

Originally Posted by Larry Hill

Anybody have any experience or used such? My top ring to land ware pattern is lacking making 360* contact. 2nd ring without anodizing on land has nice ware pattern as if it was a top ring. It looks like the top ring is allowing a lot of cylinder pressure to get to the second ring. Both are steel rings. I will lap top ring on surface plate to check for flatness.

[Larry Hill]

No but I have one. I will have to try it next time on the dyno.

[RonP]

You might want to check ring groove waviness. You will need to ask the supplier what the specification is and measure at a machine shop or send back to the supplier. The anodizing is normally used to reduce wear in the piston ring groove for production engines.

[Larry Hill]

Sending the piston back to the manufacture will be like asking the fox to watch the chicken house. It would take a little bit of work to make a piston holding fixture that would repeat to .0001. Its way easier to check ring thickness, I'm seeing .0003 variation in ring thickness.

[Todd Gross]

I questioned Hard Coat Anodizing with my Diamond Rep a few years ago. His statement on the subject was that the Hard Coat Lands will not seal as well as a properly machined , bare aluminum Land.
He said the up side of the Anodizing is greater longevity.
As for if you want to send your Pistons out for Land work, you can consider Rebco Machine in Wichita, KS. They specialize in Piston work. Outstanding quality.

[Larry Hill]

Thanks Todd for the info. I am going use these and track how long it takes to see a happy ring and land relationship develop. If you remachined the top grove top and bottom their is a good chance that the top ring placement will be too close to the top and be outside of the rules. Not sure what NHRA will do with an out of specification ring thickness. It is possible to have a valve too big or too small ether way your out.