The pistons appear to measure ok so far.

I have been cleaning the carbon off the tops etc - I think this how artificial diamonds are made. I have been soaking the pistons in diesel for a week.

Perhaps time for something stronger or give them to a machine shop.

I soak mine in Berryman's ChemDip overnight, scrape off the softened crud, soak another night in clean ChemDip, then brush and rinse with mineral spirits. The coffee can is for the first soak. The tray at lower left is what gets scraped off after the first soak. I keep the pistons inverted so loosened crud drains away from the rings.

The three pistons show the initial carbon, after first soak and final.

Others have their favorite techniques - search and see if any appeal to you.


http://forums.pelicanparts.com/uploa...1554323495.jpg

I can’t stand the thought of buying another chemical. However I am considering it. Did it clean the ringlands?

+1 on ChemDip.I use a brass brush. Carbon comes off easy. Brake cleaner for final cleaning

john

Brake clean and wd40 alternating and sometimes mixing with a scuff pad works well. I would blast and mirror polish or ceramic coat the domes personally. Builder's choice.

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If you're concerned about disposal, I didn't have to use much ChemDip, only enough to cover the crown of an inverted piston. The coffee can is slightly bigger than the piston so there's little waste.

Do wear protective gear and read the precautions. The chemistry of this stuff is different than your typical garage solvents.

Mine weren't too bad, so I cleaned them with solvent. If they were really caked, I would remove the rings so the solution had a good shot at the grooves.

Good luck,
Steve