Chrome plated top piston rings, or not.

[RaceDiagnostics]

I'm planning on doing an engine rebuild over the winter and have been putting together a list of items tio buy and have come across two types of rings, std grey iron or chrome plated for the top ring.

Any thoughts on which to go for?

 

[Rannsachair]

I'm planning on doing an engine rebuild over the winter and have been putting together a list of items tio buy and have come across two types of rings, std grey iron or chrome plated for the top ring.

Any thoughts on which to go for?

Chrome plated should last slightly longer - the chrome improves wear resistance and lower friction.

 

[RaceDiagnostics]

Longevity is not a major issue for me as the car doesn't do many miles any more, is there a downside?

 

[Rannsachair]

Longevity is not a major issue for me as the car doesn't do many miles any more, is there a downside?

Only downside I know is that they can take longer to bed in, so use more oil short term.

I may be out of date, my knowledge on this is from 30 years ago.

 

[Shox Dr]

A good article
https://www.jepistons.com/blog/piston-ring-materials-explained

 

[Cobbler]

Unlikely to be a problem in this case, but you can’t use them on chrome bores. Does anything use chrome bores now? I know Rover, when it was Rover used to chrome the top inch of the bore on some models.

 

[colnerov]

Hi, From what I remember reading years ago, you have Chrome rings or Chrome bores (liners) not both. Chrome is as said harder but it's porous so it retains oil which is why they use it.

Colin

Note to self, must type faster.

 

[RaceDiagnostics]

After doing some more reading it seems like chrome is good on perfect bores but iron is preferred if not perfect as they will bed in quicker so I will go with iron. Thanks Guys!