Piston Rings & Honing

[ducpainter]

Hard work with carburetor cleaner or https://orisonmarketing.com/products/piston-kleen%E2%84%A2

To the OP...You might contact the company to see if this product would work t0 safely remove the gaze from cylinder walls.

[MonsterHPD]

I think it's worth here to note some properties specific to Nicasil-type coatings. Nicasil is a Mahle trademark, so technically Ducati cylinders are not "Nicasil" cylinders, but I suppose the coatings are similiar. I still have some old documentation from my time at Mahle in Stuttgart, but I never worked specifically with Nicasil coatings and unfortunately it's so long ago (30+ years) that I don't know anyone to ask.

Anyway, Nicasil-type coatings are meant to be extremely smooth, one Mahle document I have says that the honed surface roughness should be Ra < 0.3, requiring an exact diamond hone process.

These numbers alone may not say too much, but for comparison a swedish supplier of brush-type hones states on their homepage that their finest grit brushes gives a surface roughness of Ra3 -  Ra10.

There's probably more to this, as surface roughness measurements are tricky to understand, and I'm no expert, but the numbers should at least say something.  

Anyway, in my opinion the "glazed" areas often seen in a Nicasil cylinder are not really glazed, they are merely polished and can be used provided there are no damages. Like Lars (mentioned earlier in the thread) earlier, I've also done both honed (by a pro machine shop) and "glazed", also with new and old rings, and Like Lars I've not noticed any difference to blow-by, oil consumption, etc.

Acc to Mahle spec, the coating is most probably 0.04 to 0.6 mm thick, but can be up to 0.10 mm, so a hone using the proper process is probably OK, but most likely not necessary.

Lots of ifs and buts, since we do not know exactly what Ducati is using, but at least some basic that might be of interest.
   

       

[rohan696]

Hi guys,

So I took the cylinders to Ducati and they suggested that I just clean them up with gasoline and warm water. No need to do anything else. I'll clean the pistons with gasoline as well using a cloth or toothbrush but nothing harsh.

Let me know you guys think and thank you all for your help!

[Orange16]

Nikasil is very hard, and you'll have a lot of trouble honing through it.  To hone it you need a diamond hone as MonsterHPD says, so you would need to find a machine shop that has experience with them to have that done.

To clean it using a ball hone is fine.  All you'll do is scratch the surface a little and take the shine off.