bottom line on napier second rings????

[fe66comet]

Info is everywhere on the benefits but materials and facings are more sketchy. The materials vary from cast iron, ductile iron to steel. I have yet to see a molly or coated ring. I am ok with the Total Seal 209697 Napier of which is ductile iron but a Plasma-Moly ring would be nice. Has anyone heard, seen or used a Moly Napier before? Thanks Guys

[jayb]

All the Napiers I've used have been ductile iron.  I'm not sure you can put a moly coating in a Napier ring because of the cross section down near the scraper part of the ring; pretty thin down there...

[Barry_R]

Napier is a second ring only.
The vast majority are plain cast iron - nothing more is needed for an N/A application
No moly is used on 99.99% of second rings (we used to have some for high boost applications - like top fuel).

[fe66comet]

I was wondering why they did not coat the second ring? The ring set that came with the piston set is moly, cast, stainless. I just want to swap the second for a little more oil control and less friction. The piston set Barry sent is a very impressive part with all the bells and whistles, the second ring will be the icing to top off the set. Beyond that I am going to add cross bolt caps and mill the block to clean some pits up. Otherwise I am getting close.

[Barry_R]

Swapping the second ring will gain you 100% noting in terms of oil control.  It will be impossible for anyone with "normal" resources to quantify the - differences if they exist.

A switch to napier on that second will reduce cross section and get a bit more power.  A really good dyno session might be able to isolate single digit gains from that move - almost certainly ten HP or less.

[fe66comet]

The engineering seems sound as far as scooping the oil and forcing it down? I also think ten HP is a reasonable gain as I have spent more for a few ponies. I am not sure at which rpm and power levels the percentage of gains would be realized most? (Frictionally )I also was considering the lack of extra heat would offer some benefit in all ranges as that seems the hot ticket these days to reduce temperatures as a whole.