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Post by triplepoweredgpz on Feb 13, 2016 7:07:21 GMT -5
How thick is the ring? I've run single ring on several older YZs and they don't last more than half the season (weekend rides) till they blow out gas pressure.Just something I have experienced. rt I believe it's 0.7mm
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Post by Curtis on Feb 13, 2016 7:18:36 GMT -5
How thick is the ring? I've run single ring on several older YZs and they don't last more than half the season (weekend rides) till they blow out gas pressure.Just something I have experienced. rt Our sponsored motocross rider used single ring Pistons in his bike, he has 95 hours on the same top end of throttle cable stretching racing. This is a KX 85 with a 120 stroker kit and heavy porting to run in the super mini class.
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Post by triplepoweredgpz on Feb 13, 2016 7:27:36 GMT -5
I was reading something about warming them up first helps prolong their life, but who doesn't warm up a two-stroke? So may be people just being people
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Post by JA-Moo on Feb 13, 2016 11:58:25 GMT -5
Ring live has a lot to do with port shapes and widths also. Race bikes are usually pretty aggressive in both. And remember, almost all of the heat transfer from the piston is through the rings, not the skirts. So One ring is doubling that load also.
Wiseco/Wossner rings are usually 1mm thick.
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Post by triplepoweredgpz on Feb 13, 2016 14:39:10 GMT -5
I'm not to worried about changing rings every season...kinda like running a big solid roller Cam on the street, you're probably gonna have to change valve springs...but we live in Canada, gives you something to do in the winter
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Deleted
Deleted Member
Posts: 0
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Post by Deleted on Feb 13, 2016 18:49:13 GMT -5
Kawasaki recommends replacing the KX 85 ring at 12 hours so I'd say you'd do well going 30-40 hours as a woods rider.Someone into serious and not so serious competition, the 2 stroke X-cross ring tends to get replaced sooner well before blow out, to maintain peak output.Just my experience over the years. It's going to be a service life factor reduction regardless and it will also depend on the ring thickness. Some are very thin, just saying.
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Post by Curtis on Feb 13, 2016 20:29:32 GMT -5
Kawasaki recommends replacing the KX 85 ring at 12 hours so I'd say you'd do well going 30-40 hours as a woods rider.Someone into serious and not so serious competition, the 2 stroke X-cross ring tends to get replaced sooner well before blow out, to maintain peak output.Just my experience over the years. It's going to be a service life factor reduction regardless and it will also depend on the ring thickness. Some are very thin, just saying. This motor was spec'd out by Bondi Racing - we just did the work. Regular maintenance is a key factor to ring life especially on a bike like this. My sponsored rider has 6 of these stroker bikes and 8 regular 85s, and the stroker motors stay together much longer than the 85s - we put a new piston and ring in them every 20 hours and a new crank assembly every 100 hours.
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Post by triplepoweredgpz on Feb 13, 2016 23:09:48 GMT -5
I wonder what the gain is for single rings? Can't be huge, but most race two stroke use them so must be worth something
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jyrgnorway
2nd Gear
H2B CAFE, H2B, H1B, F8 BISON, Z1000ELR, RD500
Posts: 468
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Post by jyrgnorway on Feb 14, 2016 2:48:37 GMT -5
I'm not 100% sure, but I believ it has to do With friction.
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Post by acceleration on Feb 14, 2016 10:14:23 GMT -5
Ring technolgy is always changing.I have talked to Keith Jones at Total Seal and Ron Beaubien at Diamond.Some rings are small and low tension to make more HP.The rings do not last as long and lose their seal quickly.And as a result you make less power at that point.And in extreme cases small rings can over heat and then start to score the cylinder.I am no ring expert but from what I was told.You know me.Listen and learn.And Not my way or the high way.That these days better ring seal means more HP.Some Pistons are now gas ported to help improve ring seal and not so much to reduce friction.So it would seem better ring sealing over less friction is good for some applications ? I recall too back in the mid 70's when I called DENCO on the phone to order parts and get some advice on tuning building etc...It was a more of a DON'T DO conversation."Don't build a race motor if you drive on the street".Subject of pistons and rings came up.Was told THEY changed their race rings after every few runs because the rings went away.They even said they didn't even hone the cylinders when they replaced their rings.Was told to get the Wiseco pistons with the L d**es rings because they were tough and will last a long time and seal well.There wasn't much available for piston / ring options back then.Things are different today.I was on the phone with DENCO for about an hour.And for the most part followed the DON'T DO advice.I still have the catalog they sent me.And still apply some of the avice they gave me.But I am old school I guess.
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Post by JA-Moo on Feb 14, 2016 15:58:10 GMT -5
Race engines are built to the Nth degree of performance. Dual rings offer a bit less then double the friction, and wear. The second ring is really to take care of any blow-by from the first ring wearing. Add in the frequency of ring and piston replacement, ring wear is not a factor as they just get replaced a lot more in a race engine.
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Post by triplepoweredgpz on Feb 19, 2016 21:25:19 GMT -5
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