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Thread: Honing Nikasil Cylinders ??? 1988 R100, 99,000 miles

  1. #1
    Registered User Manitou_Commando's Avatar
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    Honing Nikasil Cylinders ??? 1988 R100, 99,000 miles

    After pulling the heads and cylinders for re-working ( valves, springs, guides, seats) the parts will be delivered in a day or so. It's a 1988 R100 RS with 99,000 miles.

    Got a new set of rings and it was suggested to me that I rough up the cylinder bores with a ball hone before installing the new rings on the pistons. There is information on Snowbum's page regarding Nikasil cylinder honing. It seemed that Snowbum advocates using Scotchbrite pad with soapy water. Is that what he suggests. He seems to NOT advocate for using a ball hone. However, Snowbum does give space to Tom Cutter's remark that cylinders SHOULD be honed.

    Yes or no, hone at 99,000 miles on the original cylinders before installing new rings?
    If not, any suggested alternatives?

    BTW, I was fortunate to be able to move back to Colorado a few months ago. I mention this as I cannot find either the Clymer or the Haynes manuals. With these, I may have answered certain basic questions.

    Thanks,
    Rick
    Rick

    "It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so." Mark Twain

  2. #2
    Liaison 20774's Avatar
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    Tough call...Tom Cutter of course does many engines a year. I'd be afraid of getting too aggressive with a hone and taking the plated surface off of the walls. Snowbum's way is probably less aggressive and should work fine. If it doesn't, then you have the opportunity to come back and use the ball hone. Honing does take a special material hone.

    I have notes from Ted Porter who agrees with both Snowbum and Tom. Ted says to first thoroughly clean with hot soapy water. Then use the aluminum oxide 240 grit hone. The purpose of the hone is to deglaze, not to cut the grooves.
    Kurt -- Forum Liaison ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  3. #3
    Registered User Manitou_Commando's Avatar
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    It would seem that Snowbum's approach - Scothbrite + hot soapy H2O is a far gentler approach that using a 240 grit ball hone.

    Because the approaches are so different, the end result must be different, as well. One uses a stronger abrasive while the other - Scotchbrite, seems gentler. Can anyone comment to the type of Scotchbrite Snowbum mentions? I assume he's using something harsher that a household kitchen sponge, correct? Or is he suggesting using the green one?
    Rick

    "It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so." Mark Twain

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    Liaison 20774's Avatar
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    He says "3M green industrial pads"...I googled that and got the usual stuff. In my notes from the Airmail email list he mentions to use the no-carbide 3M pads. My notes says that he's listed various pads on the website, but I can't find anything other than the above. I dug a bit deeper where Snowbum wanted to know what was the grit in the pads. 3M engineers said the green pads have aluminum oxide particles...no silicon carbide. The white pads have to particles at all and it's just the plastic for scrubbing.
    Kurt -- Forum Liaison ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  5. #5
    Gerard jagarra's Avatar
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    Here is a link to the MSC site showing what they have available for hand pads, 3M and other suppliers.

    https://www.mscdirect.com/browse/tn/...ndustrial+pads
    1994 R1100RS-(5/93)-,1974 R90/6 built 9/73,--1964 Triumph T100--1986 Concours

  6. #6
    Registered User Manitou_Commando's Avatar
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    In the belief that more prudent is better I will try 3M green pads with soapy H2O to see what that does. If the rings donít seat, I can take more aggressive measures. Iíll put it all together on the Fourth and report back.
    Rick

    "It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so." Mark Twain

  7. #7
    Nutfarm
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    I've rebuilt many Porsche 911 engines with nickasil cylinders. As long as the plating was not damaged I'd clean them up with 600 wet and dry and solvent. The pistons were generally reusable. I'd replace the rings with just a touch of oil and it would be good for another 100,000. The plating can get alittle thin right at the top of the cylinder where the rings change direction.

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