Mark or anyone!
I am used to getting new rings with markings like "TOP" on one side for example. The set of rings I received have no markings whatsoever and are different to the ones I had originally on my R69S. From what I can figure, the 2 thin oil segments toghether with the wavy spring piece sandwiched in between go on the bottom piston groove with no importance to side. This would be the oil ring. For the top and middle groove I figure the middle groove would be suited for the compression ring that appears the same on both sides with identical light chamfer at the edges while the top piston groove would take the stepped ring (compression/scraper ring?) with the step facing the top of piston. With respect to the two oil segments and wavy spring, do I set the 3 openings so that they are 120 deg apart and do I need to do any trimming of the wavy spring? Please advise. Also Mark, on the pistons I see the marking Sp 0.08.....is this the recommended clearance that is required? I am going to attach a sidecar....should I go for 0.09 + 0.01mm or is 0.08 + 0.01mm ok? Is the piston set you sent me balanced?
Pierre
piston/ring configuration
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Pierre Michaud
Re: piston/ring configuration
Looking at the stepped ring more carefully tells me that perhaps the step should be facing down! Anyway, please set me straight.
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Pierre Michaud
Re: piston/ring configuration
Just noticed a bevel on the inside and outside of the regular compression ring. Not knowing if it goes on top or middle groove I have no clue as to which side should face up. If it goes on top then I believe the inner bevel should be facing up and if it goes in the middle groove the inner bevel should be facing down???????????????
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Pierre Michaud
Re: piston/ring configuration
Just noticed a bevel on the inside and outside of the regular compression ring. Not knowing if it goes on top or middle groove I have no clue as to which side should face up. If it goes on top then I believe the inner bevel should be facing up and if it goes in the middle groove the inner bevel should be facing down???????????????
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Ben Friedl
Re: piston/ring configuration
Hello Pierre,
From the diagram that I have, the stepped ring is the ring directly above the oil scrapper ring with the step facing down. The diagram does not show whether the other rings have a bevel or not, though I believe if they do, the bevel should always be facing down. From what I know about cars, the theory being that as the the piston travels down on the combustion stroke you actually don't want to "scrape" of every last bit of lubrication, other wise the ware would be excessive.
Ben
From the diagram that I have, the stepped ring is the ring directly above the oil scrapper ring with the step facing down. The diagram does not show whether the other rings have a bevel or not, though I believe if they do, the bevel should always be facing down. From what I know about cars, the theory being that as the the piston travels down on the combustion stroke you actually don't want to "scrape" of every last bit of lubrication, other wise the ware would be excessive.
Ben
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Pierre Michaud
Re: piston/ring configuration
Ben,
Thanks for reply. So if the stepped compression ring is in the middle with step facing down (upside down L cross section), then the other compression ring goes on top with the inner bevel facing up. I have two diagrams of a generic piston and ring side views and both show the top ring with inner bevel facing up and a middle ring with inner bevel facing down. As for the oil ring it is completely symetrical either way. Can anyone confirm this please as the assembly is critical! Thanks, Pierre
Thanks for reply. So if the stepped compression ring is in the middle with step facing down (upside down L cross section), then the other compression ring goes on top with the inner bevel facing up. I have two diagrams of a generic piston and ring side views and both show the top ring with inner bevel facing up and a middle ring with inner bevel facing down. As for the oil ring it is completely symetrical either way. Can anyone confirm this please as the assembly is critical! Thanks, Pierre
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Ben Friedl
Re: piston/ring configuration
Pierre,
I just bought a new piston and ring set. It was assembled when I got it. I just took another close look at it. However on the two compression rings there is no bevel on the inside circumference or the outside, they are dead square. It's a German manufactured Kolbenschmidt, if yours is of the same manufacturer they have a web site maybe you could ask them for the exact configuration.
Ben
I just bought a new piston and ring set. It was assembled when I got it. I just took another close look at it. However on the two compression rings there is no bevel on the inside circumference or the outside, they are dead square. It's a German manufactured Kolbenschmidt, if yours is of the same manufacturer they have a web site maybe you could ask them for the exact configuration.
Ben
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Pierre Michaud
Re: piston/ring configuration
Thanks Ben. The only marking I had on my piston set is on the box it came in "+MARK+swiss". Looks like a brand name that is given exclusively to Mark Huggett Gmbh by the manufacturer. I have no idea where they were made. Did you purchase your piston from Mark? I am still waiting for a response from Mark before I put the cylinders back on.
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Pierre Michaud
Re: piston/ring configuration
Ben,
Web search strengthened previous findings but still not 100% positive:
Top compression ring placed with inner bevel facing up. This ring also has both sides of the outer circumference beveled.
Middle compression ring placed with flat of L facing up (upside down L x-section)
Bottom ring (oil) is staightforward. Expander ring held in position by two scraper rings
Web search strengthened previous findings but still not 100% positive:
Top compression ring placed with inner bevel facing up. This ring also has both sides of the outer circumference beveled.
Middle compression ring placed with flat of L facing up (upside down L x-section)
Bottom ring (oil) is staightforward. Expander ring held in position by two scraper rings