Topic: Piston Ring Advice.

[BenelliSEI]

Getting ready to assemble the top end of low mileage, S/C #582. The bores have a very light hone and well within std. size. Pistons are lovely, going back in. I have this std. set of RIK, made in Japan, rings on “inventory”. Plan to use them. Any opinions or installation advice? Thanks!

[denward17]

Not really any advice, but a question:

Since you just honed the cylinders a bit, will you measure the ring end gap in various places inside the cylinders?

[BenelliSEI]

Did it. Good to go.

[WideAWAKE]

Don’t see any reason not to use em.

Did the S/C originally come with a single oil ring (not the three piece as pictured)

My K0 had a single piece ring.

The 3 piece will be an upgrade.

[bryanj]

Silver edged in top groove, black in second groove any markings face upwards

[BenelliSEI]

Thanks for the feed back.
Yes, the original oil control ring was a one piece....

[HondaMan]

I've had poor performance with using 3-piece oil rings where 1-piece oil rings were, in the same pistons. With new pistons, things worked better.
But, the 3-piece oil rings don't seem to last as long (in normal use, like commuting-touring, and lots of winter neglect, like old oil sitting in the engine for long periods) as the 1-piece version, while vice-versa in racing apps with lots of redline running. The 1-piece one will let oil smoke out at redline+ speeds because there isn't enough space for the oil to collect in the rings before pushing thru the ports to the inside (to lube the rod's small end).

I've seen the 1-piece oil rings surpass 100k miles in the early engines while the 3-piece versions (which first appeared around March 1972 in the K2) have more often showed oil consumption (and weep at the head gasket) starting around 70k miles.

So, if you are using new pistons with new rings, it shouldn't matter which type. The MC and RIK rings are the best we can get right now (and my personal favorites, anyway).

[BenelliSEI]

I've had poor performance with using 3-piece oil rings where 1-piece oil rings were, in the same pistons. With new pistons, things worked better.
But, the 3-piece oil rings don't seem to last as long (in normal use, like commuting-touring, and lots of winter neglect, like old oil sitting in the engine for long periods) as the 1-piece version, while vice-versa in racing apps with lots of redline running. The 1-piece one will let oil smoke out at redline+ speeds because there isn't enough space for the oil to collect in the rings before pushing thru the ports to the inside (to lube the rod's small end).

I've seen the 1-piece oil rings surpass 100k miles in the early engines while the 3-piece versions (which first appeared around March 1972 in the K2) have more often showed oil consumption (and weep at the head gasket) starting around 70k miles.

So, if you are using new pistons with new rings, it shouldn't matter which type. The MC and RIK rings are the best we can get right now (and my personal favorites, anyway).

How about reusing the original oil rings (single piece)? Only 17,000 miles on the clock.

[MauiK3]

Seems like they should work if they measure ok. I’m no expert, just an opinion

[HondaMan]

I've had poor performance with using 3-piece oil rings where 1-piece oil rings were, in the same pistons. With new pistons, things worked better.
But, the 3-piece oil rings don't seem to last as long (in normal use, like commuting-touring, and lots of winter neglect, like old oil sitting in the engine for long periods) as the 1-piece version, while vice-versa in racing apps with lots of redline running. The 1-piece one will let oil smoke out at redline+ speeds because there isn't enough space for the oil to collect in the rings before pushing thru the ports to the inside (to lube the rod's small end).

I've seen the 1-piece oil rings surpass 100k miles in the early engines while the 3-piece versions (which first appeared around March 1972 in the K2) have more often showed oil consumption (and weep at the head gasket) starting around 70k miles.

So, if you are using new pistons with new rings, it shouldn't matter which type. The MC and RIK rings are the best we can get right now (and my personal favorites, anyway).

How about reusing the original oil rings (single piece)? Only 17,000 miles on the clock.

If the original rings are still on the original pistons, I'd use those, instead, provided there wasn't rust in the bores to damage things. I wouldn't hone the cylinders, either, if they weren't rusted. This way, the rings could rotate back to their original positions (in time, not immediately) and re-seal the bores like they were.

The largest trouble with just re-ringing old pistons and bores is: the bores are not round anymore. By somewhere around 8k-10k miles, they warped into their characteristic egg-shape on bores #1 and #4, which the rings then settled into and wore to match. When new, round, rings are installed at that point, they almost never seal to the non-round bores, leaving the engine with a slight blowby on those 2 bores. After a time this settles into unequal compression between the middle bores and the outer ones. This doesn't usually result in serious oil consumption, but it does make for an uneven engine and often a ratty idle, causing the infamous 'clutch rattle' issue to appear - and it would make the wine in the wine glass sitting on the gastank show ripples instead of the once-touted glass-smooth engine! In actual use, this re-ringing has been done a lot and the engine is un-stressed enough that it will run that way adequately for most riders - except guys like me...