ZANE- bores and pistons

G

ghwallice

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Location
Ipswich
Tammy left the breatherlyser lock on the computer off. Yoohoo!

As some/most of you know I'm rebuilding a 750S track bike from a garbage bin full of parts. So far, so good, but I've a problem (well lots of problems really, but this forum is not the right forum...)

I'm using miss matched pistons with mismatched barrels. Rings are good. The barrels are scored, as are the pistons. And it is not as if I can go to the corner shop and buy replacements. So...

Can I hone Nikasil barrels, and how much? Must be able to quite some, cos "B" type pistons, OS,  are in the parts book.

Next concept is to get the pistons ceramic coated???. I don't really know much about this, but I have heard that there is different thickness coatings that can be applied.

So..if it comes together, I get the pistons coated ( what thickness coating??), and hone the cylinders to suit??

But, if one is using ceramic coated pistons, does that change the clearance?

Regards, Greg





 
There is a bloke in Kiwi who can redo the Nikasil. Can't remember his name but the Guzzi guys use him. Find him, get rour bores the same size and get them redone.
 
The bores don't need much of a hone to get rid of the scores, maybe 3 thou. I was under the impression that ceramic coated pistons were a good thing. Am I wrong?

Failing that, who is the bloke in NZ?

Thankyou for the tip!

Regards, Greg
 
There is a bloke in Brisbane but the reviews have been variable. This is the Kiwi mob http://www.nzcylinders.com/

I haven't used either so no personal experience.
 
I've used NZ Cylinders - they're about 1 1/2 hours south of me. Good blokes. They can certainly diamond hone nikasil bores - and do it very well.
What's the clearance on the pistons you have now - as is ?  My understanding of "growth" after ceramic coating is that it isn't much at all - maybe .0005 in - say half a thou.
Red should be able to tell you - and point to whoever does his.
 
The ceramic coating goes on the piston crown, and is good for rejecting heat (so the piston does not get so hot, the excess goes out in the exhaust). So it's no good for taking up clearance in the bore.

Typically the ceramic coating place can put a teflon coating on the piston skirts, this helps reduce friction but I don't think it adds much to the piston diameter.

i believe both coatings are worthwhile particularly for a race motor.

Cheers,
bazzee
 
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