Modern Piston Rings Materials for performance NA street engines 1

[inline6]

What are peoples thoughts on suitable piston ring materials for high performance NA engines that live mainly on the street but still get driven "properly" from time to time?

There seems to be a push for thinner steel top rings with various face coating/treatments (e.g nitriding ) are they always better than a more traditional ductile iron moly or iron rings that are slightly thicker or are there bigger downsides or more risks with steel and what are they?

There is no doubt that steel rings cope with harsher environments better which allows a thinner ring which has its inherent advantages but where do you draw the line?

what are/were the European OEMS Porsche/BMW/Mercedes etc doing on their NA motors, and i guess even on the modern turbos as they must still give longevity? any trends worth noting?

 

[PackardV8]

There seems to be a push for thinner steel top rings with various face coating/treatments (e.g nitriding ) are they always better than a more traditional ductile iron moly or iron rings that are slightly thicker or are there bigger downsides or more risks with steel and what are they?

Short answer, yes.

Current technology thin rings have less friction, conform better to the cylinder, don't flutter at high RPMs. With the proper cylinder hone preparation, crankcase vacuum control and EFI, they last indefinitely.

I wouldn't strain my brain worrying about the material details; since custom pistons will be required for obsolete engines to use good rings, just ask the manufacturer to include the best rings for your described use.

jack vines