Ring gapping

[Doc]

I'm running one those Wiseco (seizco) single dykes ring (L type) piston assy in my TM125. Finding a ring to suit the 60th over bore is proving somewhat of an issue unless I purchase another complete kit. The part number of the ring is 2264L. I have found a 2284LS ring set. It's 2 ring but the top ring looks like the L type I need. Is it possible for me to re-gap the 80th over ring back to 60th and does anyone know if the LS rings are L type top and plain lower? Questions questions 

[Lozza]

Before any of that did the piston  come packaged in a sky blue box? If yes set the oven for 200C and bake it for 2 hours and turn the oven off and leave it to cool down.This expands the piston to what it would under operating temps.Bore and hone to the THAT size.
 With the end gap to much is better than to little rule of thumb is 4thou for every inch of bore(0.1mm for every 25.4mm) so sticking to that.File the gap with a diamond file and chamfer all corners.Doing the maths it doesn't look that appealing I would like to look at one in a bore before you could say yes or no A trial run with another used 58mm?? ring would be the go.Why not just use TKJR pistons they go to 58.5mm, they have a higher dome and longer skirt though?

[Doc]

Lozza it be one of ye ol' red box kits. It's been running perfectly and the little TM is right on song but the ring will wear and already it's had a pretty hard time at Coffs DT. The reason I used this kit was the $40 price tag and I was already out to 1mm over on the bore. I prefer to use genuine pistons every day of the week but this kit just happened along. What my main concern is can I file the ring gap back to within tolerance or will the larger ring have a tendency to snap or create a hot spot/high pressure area opposite the gap? Meanwhile I'll keep hunting a 60th dykes ring as there has to be some somewhere..this ring will show up as soon as I fit the 80th ring and it snaps and sends my bore to oblivion!  this is using my foresight so I'm hopefully not making a monumental error. Either or I find another TM barrel 

[Lozza]

Doc, I would scab an old 58mm ring from somewhere,file it and see if it goes out of round in your bore.Also save your pennies and old TM barrels as all will be perfect in TM world .....soon.
Maybe try comparing your 1.5mm over to a 1mm over and see if they are bigger in diameter, if the 1.5mm is bigger then I'd say there would be buckley's chance in that working well.L shaped dykes rings are pretty stiff and they wouldn't enjoy bending a great deal.

[Doc]

yeah, think I'll hunt around for other options and keep looking for the 60th over ring in the meantime Loz. My thoughts also were the L shape would not like the extra compression and go all spazzy. No problem, will run with what I have for a few more rides and then start to panic 

[oldfart]

Doc    Have you looked up part #   2284CD ( wisceo part # page 35 )

[Doc]

I actually need a 2264L but I'll go take an optic oldfart. I phoned Serco but they said bzzzzt! sorry, try again  normal 2264CD rings are available but not L type or dykes. I see the price of a 58mm kit is 161 US bloody dollars too hence why I went the $40 way but alas..either way ya end up paying 

[oldfart]

Ok then on page 86 of catalogue ....they only carry    LT series  67.5 mm to 80mm half key stone , dykes " L "
Sorry no listing for your size  being  58 mm

[LWC82PE]

ok i was taught 3 thou per inch of bore

[Lozza]

Where does the extra compression come from
4 thou per inch it is.

[Doc]

the extra compression of the ring Lozza..not actual engine compression..I run low comp in that 

[mboddy]

So can we run a ring from a larger oversize if we file down the ring gap?

[Doc]

well once upon a time this was standard practice mboddy so long as the ring was a plain type 4 stroke ring filing the gap was considered normal if using oversize rings. This is my only experience filing ring gaps and never have I done it with a 2 smoker nor with any type rings except the flat type. With jap bikes the parts over the counter are ready to fit..not so with early british stuff or hybrids. This wiseco ring I was looking at is like an L shape in it's cross section. It sits right at the top of the piston and the L shape points up like a little wall around the top edge and this is why they refer to them as a dyke ring. The more I think about filing the gap the more concerned I'm getting that it would be a no no which is making me think it's not right for reasons unknown. I've just never been specifically told you can't do it so I thought I'd ask 

[Lozza]

Shock horror they are called Dykes rings after the bloke that invented them, who would have thought eh? Tension, compression etc means nothing as long as the ring remains concentric and in contact with the bore.Beware as they are VERY sensitive to piston to bore clearence and don't fancy to much slap or rock over TDC.That's why I would have the misgivings about this idea.
Found a spot for the Barry Sheene meeting trophy Mark? 

[Doc]

goodness.. his name is/was Dykes!! scary to think of the torment for his mother but she obviously didn't live up to the name. 

That's what i was thinking Lozza but you say it differently. I figured if the oversize ring was compessed more than yes, it may distort and this was the worry. It's okay, I'll just hunt up the right ring..I have a few more leads now