Inliners International Forums General Discussion Engines What is the difference between Plain and chrome piston rings?

I need to get a new set of rings for a motor that I just got bored out to .080. I am looking at the rings, and cant decide which ones I should get. What is the difference between chrome and plain rings? Will they break-in the same? What is the life?

Thanks,
Dan Nelson

Dear Dan;

The 'plain' non-chrome rings are softer and break in right away.

The chrome are considered stronger and used in most 'high perfornance'/high compression engines and those runing NOS. Many use them, just because of the chrome and they take longer to break in because of this.

Some feel that special honeing is required for chrome. Contact Ken at Design Performance for details.

Some feel that chrome ones last longer, but that's dependant on how the engine is operated and maintained.

Good luck.

The chrome moly rings are also Known For Not seatting right No matter how Or who did the engine work. I use the creamic Moly rings. I have bad luck with chrome moly rings Not seating.
So talk with Ken Or Mike Kirby in your area.

I have never heard of ceramic moly rings. Where can I find those, and how do they seat/last?

Thanks,
Dan Nelson

It's a coating as for how they Last well They been in my 250 for 17yrs from being a daily driver to a All out drag car. just ask your local speed shop.

Dear Dan;

Larry's right.

I used chrome once and never agian because they didn't 'seat'. I had to do the job over for free.

If this is for passenger car use, just use the non-chrome ones. You won't be sorry.

When the plain rings wear in, they also wear the hone pattern in, wich is not what we want.

Ever wonderd why most modern engines outlast far more then 100000 miles without a re-ring job or consuming to much oil on the rings?

There is not really much advance in the last 60 years of engine building anyways but chrome/molly rings is one.

Make sure you get the right specs for the chrome/molly rings or they will seat really bad.

You also need to have the right hone pattern. This is an absolutley must!

If an engine is done with the right hone pattern, clearences and gap they almost last for ever and give you great compression and much less wear than the plain rings.

first there is no chrome-molly rings.
there are cast. there are molly and then there are chrome.
plain or cast rings are the base and used in most low proformance motors.
molly is used in most high proformance motors. they seat right away on the frist start up and run in. i use them all the time and have never had a problem. only the top ring is molly filled.

chrome rings where used in motors the ran without air cleaners in high dust conditions. the wore the bores rather quickly. again only the top ring was chrome plated.
for your motor i would recomend the molly rings.

I am liking the ceramic coating on the rings idea. Should I use plain rings to get the coating on? Should I only coat the top ring?

They come already coated Just ask for a creamic Moly ring set.

Sorry about a late reply.
Just hope this helps a little.
Before ordering ANY rings for this motor, you should first talk to the machine shop that did the honing.
We hone our blocks differently, depending on the type of ring the customer is going to use, and also driving habits.
They are the professionals, and the first people to ask for advice. That's why we are in business.
As far as moly rings go, we use these in most street applications, and plasma moly for most street/strip/race applications.

If the block is honed correctly for the rings being used, there is little to no ring break-in. Rings and honing procedures have come a long way since the old cast iron ring days.

Just food for thought.

Ken
www.CustomDesignPerformance.com

I have to comment with an exchange like this one...I am ever amazed at the depth of knowledge available on this BB. I learn more just reading about other folks problems in a week than I ever learned in a month of busting knuckles.