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Cylinder honing

I'm under the impression that new rings should be introduced to honed cylinders in order for them to develop their seal. I 'm planning on honing my nikasil cylinders this winter before installing new piston rings.

Jim
 
How many miles on the bike or since last rebuild? How does the current cross-hatching look? I think in general, you should hone such that you can get the cross-hatching back into the cylinder walls...this promotes ring seating...without out, they might not seat.
 
Rebuilding 1977 R100S, changing piston rings. Is cylinder honing necessary?
Welcome to the forum! IMO, you've come too far to not do the whole job. As Kurt mentioned, how does the cross-hatching look? If it's good, I'd as least "break" the glaze.
OM
 
I'm under the impression that new rings should be introduced to honed cylinders in order for them to develop their seal. I 'm planning on honing my nikasil cylinders this winter before installing new piston rings.

Jim

Be sure and consider how you hone nikasil cylinders. They require a special hone, if required.
 
Kurt,

Already did some research on that. I have't bought the hone yet but i will be buying a 240 grit Aluminum oxide ball hone for my nikasil cylinders. Thanks for looking out for me though.

Jim
 
I would thoroughly wipe the Nikasil cylinders with laquer thinner, examine the existing cross hatch and call it good. Unless you have considerable experience it is easier to mess them up than improve them.

Old iron cylinders - yes. Nikasil, I personally wouldn't do it. YMMV.
 
My nikasil cylinders are quite polished where the rings were riding. I can still see some cross hatch but i would say they are more polished than cross hatched. I talked to Ted Porter and he said they are supposed to be honed. Your point on comfort level and experience is well taken.

Thanks,
Jim
 
I worked on Porsches for 30 years. The later 911's came with nickasil or plated cylinders, other than a good clean up I would reuse them with new rings, never touched them with a hone.

Sometimes on high mileage cars the plating would wear through at the top of the cylinder where the rings change direction. I've seen this happen on a few motorcycles with plated cylinders as well.

On cast iron cylinders, if the bore is still reasonably straight, you can use a glaze breaker type of hone. But for plated cylinders I suggest you use alittle fine sandpaper, 600 grit, to remove the carbon above the top ring. Wash them in dish soap and hot water and reinstall.
 
I have to apologize for hijacking the OP thread. I will upload some pictures of my cylinders tonight. In the meantime i would like to hear form anyone who has honed nikasil cylinders.

Thanks,
Jim
 
Here is a couple pics of one of the cylinders. They are both similar. Top of the cylinder is in the foreground. You can see some cross hatch and where the oil ring stops at the bottom of the stroke. It looks pretty polished to me. Let me know what you think.

Thanks,
Jim
 

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As I said, clean the carbon from the top of the cylinder and put them back on, they look fine.

To hone plated cylinders you need a hone with diamond or carbide blades.

I've made many cylinder liners from aluminum pipe and have had them plated by Bore Tech, and they finish hone them, they have the equipment to do the work. It's not common for machine shops to have hones for plated cylinders.

I have a BSA powered dirt bike with one of my plated aluminum cylinder liners, it's had several sets of rings over the past 20 years, never had an issue with ring sealing.
 
Honeing cylinders

I'm amazed at how many people out there have calibrated eyes! You can look at something and come to the conclusion that everything is just fine. The OP stated that the cylinders were on a 77 model so they must be iron lined.
This also reminds me of a dealer I worked for who would run his fingers through the bore and declare that all that was needed was a quick hone with a "bottle brush" hone and a new set of rings. Calibrated fingers!
The repair manual (BMW) provides us with the specs for the bore, taper and out of roundness. So if you have any questions then you might want to find someone who can actually measure these dimensions. Only after that, can you make a decision of what to do. Any real "mechanic" will tell you this. So if you want a half-as** job, take it to a half as** mechanic!
 
I'm amazed at how many people out there have calibrated eyes! You can look at something and come to the conclusion that everything is just fine. The OP stated that the cylinders were on a 77 model so they must be iron lined.
This also reminds me of a dealer I worked for who would run his fingers through the bore and declare that all that was needed was a quick hone with a "bottle brush" hone and a new set of rings. Calibrated fingers!
The repair manual (BMW) provides us with the specs for the bore, taper and out of roundness. So if you have any questions then you might want to find someone who can actually measure these dimensions. Only after that, can you make a decision of what to do. Any real "mechanic" will tell you this. So if you want a half-as** job, take it to a half as** mechanic!

Based upon a bunch of criteria, I am sure there are different levels of work recommended by a "real mechanic."
 
Compared to my cylinders ('78 R100S), it looks like someone has already worked yours.
 
IMHO best thing to do to a '77 is convert to Nikasil.

I ran my '84 for 20+ years and some 70K miles and never really needed to look at the dipstick. You couldn't say that with iron liners.
 
1982 R100RT cylinder none

Here is one of the after pictures of one of the cylinders I honed. They are nikasil, 58k miles. I used a flex hone, 240 grit, aluminum oxide. It has 8 passes through (4 cycles). I chucked the hone in a lathe, measured the rpm (210) and calculated my axial speed (17 inches/sec) for a 45 degree cross hatch. I think they look pretty good. I know that a lot of folks cautioned me against doing this but i felt confident that i would do no harm. It actually looks like i could do more because there are still some polished areas, but I think I'll quit while I'm ahead.
Thanks,
 

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Cast iron cylinders

Back when I was doing heads and cylinders, I gotta call from one of my customers about the longevity of the work I was doing on his heads and cylinders. I told him probably 75,000 miles as a guess. Is that all he asked. I asked how many miles he rode the bike a year. He replied maybe 5000 a year max. I told him to start worrying about it 15 years.
 
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