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Old 03-27-2014, 12:17 AM   #1
RUNNERBUN
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Default Compression ring position

I need some help from the experts please, I am installing a new set of rings into my motor. I opened the box and removed the rings and the instruction sheet. I incorrectly assumed that the instruction sheet would give me all the information I would require. "wrong assumption"

As you can see from the pictures the instruction sheet tells you quite clearly which way to face the rings. ie. Ring with dot and inside chamfer facing up. & ring without dot and no chamfer in either position. What the instruction sheet does not tell you is which one is in the first groove and which goes into the second. That information is shown on the fold tabs on the box adjacent to each compartment of the box. This is where my problem lies, I had already removed the rings from their individual compartments and I am not sure which came out of which. I strongly suspect that the ring with the dot came from the compartment marked second groove, but I'm not 100% sure.

Appreciate your assistance and thank you in advance.
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Old 03-27-2014, 01:04 AM   #2
MikeK
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Default Re: Compression ring position

On Hastings sets the dot up, bevel down are the second rings, the rings with no markings or bevel go on top.
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Old 03-27-2014, 01:29 AM   #3
RUNNERBUN
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Default Re: Compression ring position

Thanks MikeK, yes they are Hastings Rings. I appreciate your confirmation. As I said that is what I suspected but better to be 100% sure. I can now proceed with confidence.

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Old 03-27-2014, 03:01 AM   #4
Tom Wesenberg
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Default Re: Compression ring position

I use a ring expander to minimize the chance of warping or breaking the rings.
I also place the top ring gap away from the exhaust valve, which is the hottest spot.

When I install the 3 piece oil ring I spiral the bottom rail on in one direction, such as counter clockwise, then spiral the top rail on in a clockwise direction.
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Old 03-27-2014, 03:18 AM   #5
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Default Re: Compression ring position

Thanks Tom, just got back from a friends place and borrowed his expander.
I do normally space my ring gaps around the piston but never thought of positioning the top gap away from the vales. Thanks for the tip.

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Old 03-27-2014, 09:31 AM   #6
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Default Re: Compression ring position

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Tom, I was told that the rings will rotate on the piston as the engine is running. Is this not true?
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Old 03-27-2014, 10:30 AM   #7
Tom Wesenberg
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Default Re: Compression ring position

Quote:
Originally Posted by 700rpm View Post
Tom, I was told that the rings will rotate on the piston as the engine is running. Is this not true?
Not neccessarily.
In the 60's I worked on a Chevy V8 that had a line of steel up and down the cylinder wall because someone had all the ring gaps lined up on that piston. That's the only time I've seen such a thing like that.

When I was 16 I was hopping up a small 2 cycle go kart engine with porting and dual carbs. I didn't have the new rings yet, but just wanted to hear it run, so I mounted it to a wood board and belted it to an electric motor. I figured running at that speed would give it enough compression to fire up, but it never gave a single pop. Once the new rings arrived it ran fine. I did learn a lesson about porting on this engine though. There's a reason for the 2 bridges across the ports, and you shouldn't remove them like I did. With that much open distance the rings will expand and catch on the edge of the port. I fixed it by beveling the port edge, but this still couldn't be good for the rings.

I have a chainsaw with ring alignment pins firmly installed in the ring lands, which hold the rings from rotating and also places both ring gaps in a straight line. I can understand not wanting the ring gaps to be in the port area, but don't know why the factory lined them up to each other.

Last edited by Tom Wesenberg; 03-27-2014 at 12:26 PM.
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Old 03-27-2014, 11:44 AM   #8
Patrick L.
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Default Re: Compression ring position

Funny you mention that. As a youngster trying to make a go-kart go faster I kinda did the same thing. I wanted to port the engine [580 West Bend 5 port] and the procedure is to square off the top side of the ports then raise them slightly. So, trying to top this and do one better I just turned it into a single port. It went like crazy for about 100ft.

As for rings turning on the pistons, they do. A couple years we fixed a little 0-200 Continental a fella was having trouble with. This engine had been returned to the rebuilder twice due to oil consumption and loss of compression. We found the cylinders very tapered, apparently enough to allow the rings to walk into gap alignment. We just straightened out the bores and the engine has been out running ever since. Every time I've seen an engine line up the rings [ that weren't pinned] I thought someone did it purposely, apparently thats not always the case.
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