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Discussion Starter · #1 ·
I'm still working on the rancher 350. I have had the cylinder rebored 1 size over and purchased a Numura piston and rings. My question: Is the placement of the two top rings important? The reason I ask is 1 is slightly wider (not thicker) than the other. They both say 25 on them but 1 says N and the other NR. I called Numura and the service guy seemed like he never had been asked this question before and said well put the wider one in the deeper slot. I have measured both slots for width and depth and there is no difference. Could it be I just got 2 rings from 2 different runs?
 

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Put each ring into the cylinder one at a time about 1/2 way down and take a feeler guage and check the gap on the rings, i think you should have around 8 to 10 thousandths gap if not you wil have to file the ends of the roing to get proper gap and usually the letters , numbers face up when in stalling the rings.
 

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Discussion Starter · #3 ·
I did that already, what I want to know is if it matters which ring goes in what slot since mine are not identical.
 

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Does one of the rings have a shinny finish and one a dull finish ( sides that contact cylinder) shinny ring second groove and dull finish top groove. any writing, numbers or bevelded edges always up.
 

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I'm still working on the rancher 350. I have had the cylinder rebored 1 size over and purchased a Numura piston and rings. My question: Is the placement of the two top rings important? The reason I ask is 1 is slightly wider (not thicker) than the other. They both say 25 on them but 1 says N and the other NR. I called Numura and the service guy seemed like he never had been asked this question before and said well put the wider one in the deeper slot. I have measured both slots for width and depth and there is no difference. Could it be I just got 2 rings from 2 different runs?
the ring with N on it..goes on the top of piston..facing up..the ring with NR..goes in the second gap from the top of the piston..facing up..any piston ring always has the letter facing up..simply because the rings are tappered..you can't tell by looking at them with the naked eye..thats why the letters face up..hope this helps.
 

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Discussion Starter · #6 ·
Can you tell me why the N is on top and the RN is on the bottom? Is it vital that the rings are in that order? I just installed the cylinder and don't remember which was up. I had a heck of a tome installing the spacer and bottom rings in the cylinder.
 

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Can you tell me why the N is on top and the RN is on the bottom? Is it vital that the rings are in that order? I just installed the cylinder and don't remember which was up. I had a heck of a tome installing the spacer and bottom rings in the cylinder.
read my other post above..the rings are lettered for the simple fact that they are tappered on the edge..and yes..it does matter which ring goes where, the very top ring is a higher compression ring than the second one...like i said..to the naked eye..you can't see the difference..trust me on this..the N needs to be on the very top grove..and the NR needs to be on the second grove facing the letters up...if they are not in the right grove..then they wont last very long...if you decide to tear it back apart, make sure they are in the right grove..and when you put them in the grove..make sure the ring space ends are at lest 60 to 70 degrees away from each other..even the oil rings..do not line the spaces of the rings up.or you won't be getting very much compression.
 

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Here is a ring placement diagram that Moose posted before.



Uploaded with ImageShack.us
 

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better to do it now..then have to tear it down later..just to have to rebuild it all over again !..lol..case in point..try rebuilding a trx250 motor top end job..get it all back together..screw in the last bolt..only to look down on the bench..and see that you left out the timming chain guide !!..lmfaooooo.
 
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