How to Mark Pistons
 

I would like to match mark the pistons and cylinders from my 3.6 engine. I prefer to use an electric etcher so as not to impose any residual stresses into the parts.

To mark the cylinders, I believe it safe to etch markings on one of the cooling fins of each cylinder without impacting the integrity of the cylinder. However, I am less certain about marking each piston. My guess is that I should be able to place etch markings on the inside wall of each piston's skirt, but would like some comments from folks who have successfully marked pistons in the past.

I am talking about making small figures, about 1/4" in size to pair up each piston with its mating cylinder of the motor.

Is this location OK or is there a better place or technique for match marking pistons?

I guess that the lack of response to this post is an indication that no one stencils part numbers on their parts.

I use a marker on the cylinders (the fins can break easily so do not feel comfortable using a stenciler) and do same with pistons. When cleaning they are done one at a time so they do not get mixed up and can be remarked. Once ready for assembly a little carb cleaner takes the ink right off.

I mark all of my stuff.............

I marked with a paint pen the cylinder #s on the top fin adjacent to the thru-holes for the studs. Also, you can engrave the numbers on the base of the cylinder where the casting markings are located and the height groups, etc. When I had my cyl. replated by US Chrome, they took it upon themselves to stamp a 965Q inventory mark at the base area. This would be above the base sealing surface. I don't think it's a good idea to engrave on the cylinder surface that's below the sealing surface, within the case spigot area.

For the pistons, you can engrave it on the dome/crown. If you look closely enough, you can see some stampings in the piston already.

http://forums.pelicanparts.com/uploa...1333659098.jpg

The inner skirt area is OK too. A more solid location is the underside of the crown next to the skirt. In the picture below, it'd be the 2, 5, 7, 11 o'clock positions

http://forums.pelicanparts.com/uploa...1333659077.jpg

Thanks so much. I was going to etch a mark on the inside of the piston skirt, but your suggestion is probably better.

I have used indelible market and paint in the past; but, there was the one time that I absentmindedly cleaned the pistons with brake cleaner, and the paint immediately got cleaned off. So, I have to account for my tendency to be absentminded!