Finally was able to get some decent photos. Interesting that you can see the outer "moly" layer. I did not notice that until I looked at the pics. Still looks symmetrical to me.

 

The difference is normally the curvature of where these 2 dots are:





From THIS photo it looks like the curvature of where the red dot is is flatter than the one at the green dot. Are those 2 places identical in circumference?


If the curvature is the same and there are no other markings as you have mentioned, then flip a coin as its not going to make any difference.

 

If the curvature is the same and there are no other markings as you have mentioned, then flip a coin as its not going to make any difference.

Thanks. I found this on the Federal Mogul site. It sure looks like the top ring is symmetrical but their drawing has the bottom corner not lining up. Looks like a drafting error though not a radius/chamfer. I will give them a call Monday.

 

Closing the loop. Talked with the tech on the phone and he stated the top ring is barrel faced and is symmetrical, so can be installed either way.

 

Your top ring is barrel faced and symetrical as tallguy found out for you. The curved ( barrel) dace allows the ring to maintain seal ( mainly at TDC and BDC) when the piston is changing direction . There is a small amount of piston "rock" during that time and a "square faced" ring ( pre '60s) would "dig in" to the cylinder wall and create a "ring ridge" that made boring the block to remove it a must. IF it had an internal bevel ( that would face up) it would also have a dot or mark that would point up. When rings have the bevel it is put there to cause the ring to "twist" and improve ring seal in the piston itself. Cylinder wall seal is the primary function of a ring but it also has to seal on the ring lands themselves to limit compression loss there.
Randy

 

I have the same ring set in std bore. My buddy unboxed them w/out checking the order they go in (inside of the box says what ring goes where). I called the manuf and they said the unmarked ring goes in first groove with no specific up/down orientation, second groove takes the ring with the dot or "top" indicator, either of which facing upward and finally the obvious third ring combo.

 

You can also look at the face of the ring that rides on the cylinder wall. Top rings are "usually" plasma moly faced and appear "shiny" as opposed to the second ( cast iron material) that has a black phosphate finish and no shine until it seats or breaks in. The second ring is often called a "second compression ring" but that is not true. The second ring has a visible "taper" on the face to literally act as an oil scraper because it is smaller at the top and larger at the bottom. This ring loses function ( pretty much anyway) when the taper is worn to the point where the entire face is shiny.
Randy