Honda piston rings

B

BGTLS

New Member
Hi, I am building a 79 honda cm185 into a cafe racer with some of my high school students. The motor needed a top end rebuild. We have everything ready to go back together but I have a question as to the order of the two top rings. One is all black while the other is black with a silver outer edge. Both are marked with an N so I know which side of the ring is up, that is not a problem. The problem is that I would always say the silver edged ring goes on top and the original confirmed this with the silver edged ring on top but in this case the silver edged ring has a small notch the thickness of the silver edge on the bottom outer edge of the ring that the originals did not have. I have never come across a top ring that has the bottom outer edged notched. The notched bottom is always the middle ring. The all black ring does seem to have sharper corners than the silver edged ring which to me indicates it is the middle ring. This small notch is really throwing me for a loop though. Have any of you encountered this or have an answer as to which is the top ring and which is the middle ring?
Thanks,
Brian
 
a good way to tell is actually to get a surface plate, or other ground flat surface, and press a ring against it, on the edge, if the ring stands straight up, it's the top ring and doesn't matter which way up, but if it has a stamp, put that up. if it stands at a slight angle, it's the scraper, and goes second, and the angle it leans to goes to the top, the oil scavenging ring should be obvious
 
Roc City Cafe, thanks for the method and I will have to try that if I can not find a definite answer. Checking them with your method would be no problem but I had the students already install the rings and slide the cylinders on putting the silver edged ring on top as it seamed to be right at the time but now I am second guessing myself. It was kind of a pain and we ended up installing the pistons in the cylinders first then sliding the wrist pins in and put the retaining clips in with the pistons already partially in the cylinders. I really do not want to pull it apart but will have to if I do not get a definite answer. I am really wondering if anyone has encountered a honda brand ring that instead of a chamfer on both sides of the silver edged ring has a small notch on the bottom of it. If so did you install this ring as the top ring? Or has anyone ever seen a honda brand set of rings that uses the all black ring as the top ring and the silver edged ring as the middle ring?

Thanks,
Brian
 
BGTLS said:
we ended up installing the pistons in the cylinders first then sliding the wrist pins in and put the retaining clips in with the pistons already partially in the cylinders.
Click to expand...

I usually do it that way.

jugon.jpg
 
AlphaDogChoppers, Roc City, or anyone else, have you ever come across a set of honda brand rings that had the middle ring with the silver/chrome edge and the top ring that is all black? This just seems wrong to me but you never know, the new rings are definitely not the same as the old ones so maybe honda changed things up. But I say the chrome edged ring should be the top one but why the notched bottom on the outside of the ring?
 
a good lesson for your students would be to take the long way, double check and feel confident that everything in the machine is right, patience is something that can only be taught by example
 
You must log in or register to reply here.

DTT Light or Dark

  • DTT Light

    • Spread the Love

    Back
    Top Bottom