New LSX supercharged COPO camaro engine has

Mahle .043" x .043" x3mm
Ductile iron top with radius molybdenum face
Plain cast-iron tapered 2nd
Chrome-plated oil rails with low-tension expander

GM 572ci 720R engine
Plasma Moly top rings (unsure if steel or ductile)

Ford Supercharged 5.4L
Plasma moly steel top ring Mahle

6.0L LS Corvette engine
Plasma moly steel top, iron second

Dodge Viper V10
Plasma Moly ductile top ring, iron second ring

6.4L Hemi
Plasma Moly steel top ring, iron second

Just doing some research. I don't believe mercury racing used gapless ring sets in their HP engines? Unless maybe on the new stuff like 1350s? Idk. Its interesting some of these new modern engines, are still using conventional rings, making more HP per ci than ever, thinner oils than ever, longer oil change intervals than ever, and so on.

Be careful with your research sources. A lot of terms and nomenclature gets regurgitated with no thought or verification of accuracy. I know Ford has been using steel (not moly, just steel) top rings for a LONG time on the 5.0 engines. I doubt very much any of those factory engines you mentioned are using Moly top rings. "Plasma moly" and "steel" usually don't go together in the same sentence when talking about rings. There a lot of coatings available for steel rings, but "plasma moly" isn't one of them AFAIK. I could be wrong and I'm going to do some checking, and if so I'll be glad to apologize...

2010 Ford Supercharged 5.4L

Plasma Moly Carbon Steel Top ring

Mahle part 42112CP

http://catalog.mahle-aftermarket.com...rId=784222&d=t

6.0 LS GM Engine

Plasma Moly Carbon Steel top ring

Mahle #41858CP

http://catalog.mahle-aftermarket.com...rId=615547&d=t


6.4L SRT Hemi engine

Mahle #42156CP

Plasma moly Carbon Steel top ring

http://catalog.mahle-aftermarket.com...Id=1206357&d=t







Isnt "MOLY" a coating on the face of the ring, and "plasma" the process used to apply the coating? I've always assumed a top ring is either Steel, or iron, with a "MOLY" coating applied to the face. Pretty sure OEM's have been using moly faced steel top rings for some time now.

Dan, if you were to use the piston rings JE suggests with those inverted dome 4.500 bore pistons, these would be them.

http://www.summitracing.com/parts/jep-j100f84500-5

http://www.jepistons.com/Products/257942.aspx

It was a oil containment issue(had to use that line) looks like may have been from valve guide/seal or possibly intake sucking oil.speaking of rings the trend now is a very low drag, and a very specific hone to match the rings, down side to this is oil control, that old balancing act. Also crankcase pressure can cause oil to be forced by the rings, several things to look at here...

i would not install a low tension ring in a endurance marine engine .

imo you can not go wrong with total seal ap rings.

Inline with the ring talk, What about the piston design Icededpple is using - meaning the 'antidetonation' or sometimes called 'contact reduction' grooves ?
I know what the manufactures say about them but it seams alot of prof builders don't say much at all about them.

Seen this for a bit in the 2 cycle world before 4 cycle apps. With 2 cycle, it supposedly holds more oil in those apps. Remember, oil is air or fuel fed.

Anybody have any info either way ?

I`d rather have a flat top personally, less chance/area for the flame front to go bad.

That's what a 1075sc does and I think its a great idea less area for the piston to absorb heat.