G2 which Way Do the Rings Go?

[andyleonard]

I just got a rebuild kit from BGW and the top 2 rings have no markings on them and one of them has a tapered profile. Which is the top ring and which way up does the tapered ring go into the piston groove? Thanks.

[on_the_fly]

The one with the tapper is the second ring. With short side up=\ , usually there are some kind of a marking on rings, might just be like a letter like (R) but usually any markings go up and I have heard of a few with no markings that apparently didn't matter witch way ya put them. But that tapper does matter.

[andyleonard]

There are no markings on the rings whatsoever and they are identical in color and material. One ring looks completely symmetrical and I'm guessing goes on top. The tapered ring has a 90* face that contacts the wall and a flat bottom (or Top) but the other horizontal is not at 90* to the face and the inside height is .010 smaller than the face height.

Does the tapered side go up or down?

[invalidsession]

Originally Posted by andyleonard

There are no markings on the rings whatsoever and they are identical in color and material. One ring looks completely symmetrical and I'm guessing goes on top. The tapered ring has a 90* face that contacts the wall and a flat bottom (or Top) but the other horizontal is not at 90* to the face and the inside height is .010 smaller than the face height.

Does the tapered side go up or down?

Tapered side up.It's what used to be known as a scraper ring. Also, index the rings when installing. 95 or so degrees away from each other on the gaps on typical three ring pistons with the upper ring gap as far away from the spark plug as possible. This prevents combustion gas shooting through the gap in the rings and the indexing helps improve compression. Use assembly lube and hand rotate the crank before completion to ensure everything is located correctly and not binding.
Old school racing practice but still holds true and here's another old tip for you gear heads; Indexing spark plugs. Mark the position of the electrode tip and work out where it faces the intake valve, add or remove shims to place it thus. That old chestnut was worthy of a 16 HP gain on a Lotus twin valve back in the day. Hope that helps.

Chris.

[jace1975]

Never thought about that, but sounds like a great tip Chris. thanks!

Jason