Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board Three piece oil control rings

With all the recent discussions of smoky exhausts on A65's IM wondering if anyone has managed to find a three piece oil control ring which should be much better at controlling oil consumption.

Looking at the original A65 workshop manual (65-68), it mentions that the first ring is plain, the second ring is tapered (presumably to help reduce oil consumption) and the third oil control ring is plain but with two scraper edges. This is interesting as all of the rings I have used (JCC, Gandini and even Hepolite) have never been supplied with a tapered second ring. Even looking at the Hastings ring catalog shows that the first and second rings are identical with no taper and the oil control ring appears to be single piece.

On my B44 which had smoking issues, I eventually resorted to using Cords Duraflex rings which use a three piece oil control ring and a tapered second ring. These rings were recommended by the now defunct OJT engineering co in the UK and did cure the problem.

Three piece oil control rings generally consist of two thin scraper rings separated by a corrugated spacer. I Assume they work by being much thinner and are therefore able to exert greater pressure on the cylinder allowing quicker bedding in.

IM was wondering if a three piece oil control ring is available for A65's and if so who sells them?

I might contact Cords Duraflex and see if they manufacture a suitable ring set. Not sure if anyone else has used this type of ring on an A65 but it certainly helped my B44 smoke problem.

Thoughts and comments welcome.

Standard issue rings on a T150, therefore available for B25.

There isn't enough room for them on the standard Hepolite pistons. If you machine the oil ring groove you can get them from total seal.

As a point of interest, I think Deves has modified their 650 ring to fit the Hepolite's shallower ring groove. Was a time when their 650 rings would only fit the pistons Triumph made in house.

Thanks for the replies, I contacted CORDS Duraflex via their website see CORDS Contact page they mentioned that they are able to supply a ring set for A65's pistons in standard and various oversizes. They said that these rings will fit the two 1/16 compression grooves and the 1/8th oil control ring on an A65 Hepolite type piston. They can supply a set for £40 plus postage depending on your location.

As mentioned, I have used Cords rings on my B44 and they worked well at stopping smoke in the exhaust. I cant see why they wouldn't work well on an A65.



All the ring profiles used were not solid but multi piece as seen via this diagram




I seem to remember the first compression rings were two piece and flat, then the second compression rings were also two pieced but cupped with the top ring facing down and the bottom up.The oil control third ring was a three piece oil control ring with corrugated separator. The top ring was cupped down wards and the last ring was flat.

These rings definitely helped me and I now have no smoke at all, I would recommend them for use on an A65 of you have smoke issues.