Cleaning carbon from pistons in short block ?

[Kern Dog]

Hey guys,
Any day now I expect to get my heads back from the machine shop. Before putting them back on, I want to clean the carbon from the tops of the pistons. Its not as if it is caked on, but there is enough to prompt me to want to clean them. The engine was apart in 2011 and had about 3500 miles on it.
In the past I have cleaned pistons using a brass wire wheel on a drill. I did each one after rotating the engine to TDC for each hole. I never pressed hard enough to gouge a piston.
What have you used to clean your pistons while they are still in the engine?

 

[Meep-Meep]

I typically don't mess with it. The particles get trapped in the area above the top ring and that's hard to clean out. If you have to I'd carefully scrape while holding a vacuum cleaner hose over the action.

 

[kb67mopar]

I typically don't mess with it. The particles get trapped in the area above the top ring and that's hard to clean out. If you have to I'd carefully scrape while holding a vacuum cleaner hose over the action.

You could rotate the engine after cleaning to reveal the debris stuck to the cyl wall and wipe with a clean rag to get most of it out. I agree though to use the vacuum. A brass brush is about all I'd probably use since it shouldn't scratch.

 

[Supershafts]

Put it back together and run it, floor it more often and you won't have carbon, don't let it idle around and baby it

 

[67 coronet]

if this is sitting in the frame,DO NOT CLEAN THEM!debris will get down in the oil pan and get sucked up into oilling system.may damage your bearings.if on stand,clean with good brass brush or roloc bristle brush above 1000 grit.do this with eng upside down and vacuum running while you do it.run each piston upto the deck to clean it and spray down with carb cleaner before going to the next one.
gm actually issued a tsb(technical service bulletin)about people cleaning there intake manifold surfaces with roloc fiber discs.the minute peices were getting sucked up into the oiling system and causing motors to lock up.

 

[eric383]

If you really want to clean the carbon off, when the piston is at TDC wipe some vasoline around the outer edge of the piston so it will fill the gap between the piston and cylinder wall. When you are done cleaning the piston just take a toothpick and clean out the vasoline and after rotating wipe the cyl wall off. This will prevent any junk from getting between the piston and cyl wall.