What's the best way to remove most or all the carbon build up on these pistons without taking them out of the block?

I tried soaking them in WD40 and while they were at TDC lighting scuffed them with a 000 scotchbrite pad. Due note the areas with no carbon come out fairly clean.




I'll be rebuilding the topend so i can sell the car.

 

go get your toothbrush and scrub the piston tops with some simple green

it may not be perfect shiny new.

so why u doing this if youre going to sell it?

 

brake cleaner + non abrasive scotch brite pad
Id be more worried about cleaning up those sleeves to make a clean mating surface.

 

yeah i was going to head off to the store after work and look for the yellow 3m bristle roloc. I hear good things about them cleaning up hard surfaces. I hear the old method and pads are not ideal to use on vital surfaces anymore.

OLD



NEW


Unless you think the old disc type will be okay

 

Pistons look quite clean to me, I would be more worried about the sleeves?

 

engine degreaser