Honing Nikasil Liners

[Momus]

Anyone?

a grinding stone or carbide burr

Any particular grinding stone or carbide burr would you use? I'm a bit afraid of a Nikasil flake come off as soon as I touch the liners

Use a Dremel with a diamond coated burr- the burrs are readily available and inexpensive.

[ptuomov]

I would not consider changing from steel to aluminum bores an improvement for most applications. Maintaining bore roundness and ring seal in high specific output engines will always be a concern.

But I actually tighten clearances (from the OEM clearances) changing from steel to aluminum/nikasil sleeves.

Due to it being used in aluminum bores, it does transfer heat more readily, and bore roundness and distortion tends to be more of an issue. In some engines I have had the Nikasil plating thickness doubled to improve bore roundness at operating temps.

(I may be over-inflating the bore roundness/ring seal issue with aluminum bores. It is common practice to bore many stock cylinder motorcycle engines 3mm (0.118 in.), for drag use, and many do not consider maintaining bore roundness an issue. But I am a bit particular about ring seal.)

I have a slightly different perspective on the bore roundness issue. In my opinion and experience, one can get a rounder bore and better ring seal with open deck aluminum cylinder towers with Nikasil coating than with anything steel/iron sleeved, provided that the cylinder tower wall is thick enough. This is because aluminum block with Nikasil coating allows for very tight cold piston-to-bore-wall clearances, because the open deck towers are less distorted by head bolts, and because open-deck aluminum towers are so good at transferring heat and keeping the whole tower at similar temperature at a given level.

Agreed on the heat transfer, clearances, durability, etc.

[Matt80]

a grinding stone or carbide burr

Any particular grinding stone or carbide burr would you use? I'm a bit afraid of a Nikasil flake come off as soon as I touch the liners

I would try and use the appropriate curved rat tail file and see if you can't knock the edge off that way.

run the file around the bore not up and down.

should have been chamfered before nikasil.

Thanks, it seems that it wasn't chamferred

[Matt80]

a grinding stone or carbide burr

Any particular grinding stone or carbide burr would you use? I'm a bit afraid of a Nikasil flake come off as soon as I touch the liners

Use a Dremel with a diamond coated burr- the burrs are readily available and inexpensive.

Thanks, good idea indeed

[Matt80]

Hi, I have a block Nikasil liners that show a sharp angle at the bottom where the liners end and the piston is at BDC:
what kind/type of tool would you use to deburr there?
I know Nikasil is quite annoying and operation could be risky

What about a fine abrasive flap wheel? I fear using a stone

[bentvalves]

the nikasil will likely shred it quick, the cheap diamond burrs are the answer I think.