Dave Ett wrote:Theorizing here, but a single ring piston of the same dimensions will cause a slight drop in compression since there's only one ring to contain the gasses. Two rings means twice the seal.
I guess it's not much, and the reduced friction makes up for any loss of power.
Anyhow, so long as the piston is the same height from little end to piston crown I can't see how it'll have any effect on compression.
Best to think of things in perspective here..
A single ring has the benefit of less friction so you theoretically get more performance but to be honest, the road going rider probably wouldn't notice anything great except a nasty bit of piston slap after a few thousand miles.
Running plated bores you would expect the ring to wear long before the barrel creating problems when the piston starts to rock about a bit - no bottom ring to support it any more and all the accellerated wear etc... - problems, problems...
They are designed to go into higher performance engines i.e. something like a TZ or RS and you would re-ring it regularly, even if they look good.
You can't really do this to a road bike with any sense of economic justification but sayng that, I've tried a set of Wiseco pro-lite single rings in the YPVS and it gave about the same top end power but the torque was up as was the mid range grunt and the compression has settled in at 145 - 140. Even after a 500 mile maintenance strip down there is virtually no blowby and the compression is steady but it runs a steel bore, not nickle silicon c.
I'd keep the single ringers if you can affort to maintain it - just coz it's different but if you want reliability and originlity (vanity) then use the blueprint item.
Bikes are there to be fun and we are all part time / wanna be race technicians, well I am at least and finding something off the wall in your bike is (I think) something very pleasant.
Any chance of some images chap ?
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These aren't the droids you're looking for.
Last edited by Binka on Fri Mar 17, 2006 5:42 pm; edited 1 time in total