Cleaning pistons & cylinders?

[khamul02]

Before I do this I wanted to double-check. I have read several threads about using an ultrasonic cleaner on pistons and cylinders. The majority say it is ok with dawn dishwashing liquid. Some people say 3 30 minute sessions with a wipe down between works well. My questions are:
Is this in fact safe for nikasil and everything else?
What else should be done after, red scotchbrite on the cylinders? Measurement check? Re-ring and reinstall?

My preference is to take care of this phase myself but is it just safer to send everything off to a machine shop for cleaning and inspection? This engine probably has about 60k on a top-end rebuild.

[Speedy Squirrel]

I have only done cylinders ultrasonically. They turned out well, inside and out. It certainly doesn’t cause the nikasil to flake off or anything like that.

Be sure to oil the walls well before assembly. They come back from the process really, really clean.

Never tried pistons. I don’t see why it would not be safe for them as well.

[targa72e]

I have found that some additional work is needed before putting P&C in my home utrasonic cleaner. I have general done a good de-greasing to get things clean. Carbon on piston tops usually requires some soaking in brake or carb cleaner. Once things are cleaned up Ultrasonic tank with Dawn works good for final cleaning. Usually still scrub cylinder walls with red scotchbright.

john

[Henry Schmidt]

Heavy carbon deposits are generally freed up with a little heat (oven to 130-150 F) and a couple coatings of Easy-Off oven cleaner. If you leave it on too long, aluminum turns anthracite in color.

This Easy-Off coloring process (caustic soda) is pretty cool if you're trying to put an aluminum case engine in an early car and you want the magnesium look.