A Very Small Scratch in Alusil Piston

[jamesjedi]

Hi,

I made a very small scratch in one alusil piston while trying to remove a stubborn clip. Would it be recommended to file or sand it down enough to make it unnoticeable to the touch? These pistons look perfect otherwise.

I know it would be great to get CP pistons and replate, however I would like to use these pistons.

Thanks
James

[gomezoneill]

I wouldn't worry about it. The rings are touching the cylinder wall the piston does not make contact with the cylinder wall. Maybe use some emery cloth on the scratch.

[1979-930]

DSS Racing actually cuts grooves in the piston skirts.
Some hypothesis about carbon deposits having room to escape without damaging the cylinder walls.
Anyway I wouldn't worry about a scratch.

[Snitzler]

I would burnish it out, just don't make it deeper.

[jamesjedi]

Ok Thanks for the replies. I was vary disappointed in myself for making the mark. I will try to remove the edge.

Thanks again
James

[Bob Kontak]

Originally Posted by jamesjedi

I will try to remove the edge.

Just use something like 220/320 wet sanding paper and your finger tip with water. Don't over work it.

When I did the top end on my 81 in the 90's, there was a vertical score on one of the alusil pistons. Something got in there. Piece of carbon?

It was not huge but it was definitely there.

I did not touch it as it went right back in where it came out. Doing fine 22 years later.

[jamesjedi]

Thanks Bob.

[Eagledriver]

Don’t mess with it. The aluminum piston is softer than the cylinder wall. The scratch won’t matter. If you try to “fix “ it, you’ll remove the ferrous coating on the piston. That coating is there too keep the pistons from “gauling “ with the aluminum cylinders.