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esr nikasil coating ???
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Posted by: plummer1111

i have a esr cylinder with nikasil coating and it is chipped. im wondering what are my options. can i bore it out and just use it like that or do i need to get it coated after boring.
thanks chris

Posted by: punker69q

Nikasil needs to be chemically stripped before boring, because it is too hard for common cutting tools.

Posted by: Rich250RRacer

Try US Chrome, I've had a few cylinders done there. Great work.
http://www.usnicom.com/

Posted by: wilkin250r

I haven't worked a whole lot with nikasil, so somebody feel free to correct me if I'm wrong.

However, I don't think I'm wrong.

A standard cylinder is usually cast aluminum with an iron sleeve pressed into it. However, nikasil is generally coated over bare aluminum, no iron sleeve.

The iron is needed because aluminum is just too soft, if you started rubbing an aluminum piston against an aluminum bore at 8000rpm, it would chew itself up. But iron has it's own complications, it has a different thermal expansion rate.

Nikasil solves both problems. It can be coated over bare aluminum, obviously much thinner than an iron sleeve, and nikasil is very hard and resistant to wear and abrasion. A solid aluminum cylinder (with nikasil coating) has a thermal expansion rate almost identical to the aluminum piston, so clearances can be set much better.

That's a little history and tech knowledge. However, this means to YOU that you can't just bore out the nikasil like a standard cylinder, because it isn't a standard cylinder. There's only bare aluminum under there. It HAS to be re-plated.

Posted by: koh0001

Very good.. I think you said it all. You always do such a good job.

wilkin250r we are glad you are here.

Posted by: jas250r

since somebody brought this up and i seen a cylinder on ebay that was a stock cylinder with what i thought it said was a alumuinm sleeve with a nikasil coating. Can you just have the iron sleeve pressed out and just nickasil coat it? I haven't seen a cylinder without a sleeve in it, just curious? If you do have to resleeve it with alumiunm can you choose the bore size? like a 295 resleeve? but with nikasil

Posted by: Rich250RRacer

quote:
Originally posted by wilkin250r
I haven't worked a whole lot with nikasil, so somebody feel free to correct me if I'm wrong.

However, I don't think I'm wrong.

A standard cylinder is usually cast aluminum with an iron sleeve pressed into it. However, nikasil is generally coated over bare aluminum, no iron sleeve.

The iron is needed because aluminum is just too soft, if you started rubbing an aluminum piston against an aluminum bore at 8000rpm, it would chew itself up. But iron has it's own complications, it has a different thermal expansion rate.

Nikasil solves both problems. It can be coated over bare aluminum, obviously much thinner than an iron sleeve, and nikasil is very hard and resistant to wear and abrasion. A solid aluminum cylinder (with nikasil coating) has a thermal expansion rate almost identical to the aluminum piston, so clearances can be set much better.

That's a little history and tech knowledge. However, this means to YOU that you can't just bore out the nikasil like a standard cylinder, because it isn't a standard cylinder. There's only bare aluminum under there. It HAS to be re-plated.

US Chrome will coat over an iron sleeve, so if you have a nice ported cylinder that's about at it's limit for boring, you can have it coated to save it. When the Nikasil wears out you have it recoated. I have a nice cylinder that's at .050 but very loose, and this is where I want to keep it, so they will bore it to straighten it then coat it to my requested size.

Posted by: GOTFEAR

Sleeve it you can allways hone and bore the cylinder and you can get it bored at yor locale shops faster than shipping out a n- seal cylinder

Posted by: beerock

quote:
Originally posted by GOTFEAR
Sleeve it you can allways hone and bore the cylinder and you can get it bored at yor locale shops faster than shipping out a n- seal cylinder

yep my thoughts as well, also, re nikasiling a cylinder cost alot mroe then a piston and a bore and hone job imho nikasil is not worth it.

they can work well as long as you maintain the crank and piston periodically. which means, replacing the piston and rings often and keeping tabs on the con rod play etc..

the way these motors are, especially with 88 rods and 86 pistons something will blow and ruin the cylinder coating... thats why i dont like it.

Posted by: plummer1111

thanks for the info guys. i have a big bore sleeve, but it loooks like the ports are differnt more ports in the esr cylinder. if someone was to do the ports on the sleeve would it work.