Removing carbon from pistons and heads

[mwctexas]

I've got my R90/6 top end off, pistons are off and going to replace the rings. Right now, I've soaked the pistons and along with scotch bright,WD-40, serious elbow grease I'll eventually get the tops of the pistons clean, down to shiny metal. The heads are a different situation...It's going to be a bear to clean them. Couple questions, please.
1. Does all the carbon need to be removed from the heads or just the potential hot spots?
2. Is it possible to use walnut shells or a similar media to blast? Is a drill wire brush attachment too severe?
3. Do you know of a way that will work, I can do?..
Any suggestions will be greatly appreciated....thank you..Mike

 

[20774]

I'm not sure of the benefit of getting things squeaky clean...it's just going to get dirty again and pretty quickly. That said, Oak's recommendation is a product by Gunk called Hydro Seal II. I used it on my top end a number of years ago. It takes time to work, but is not harmful to the metal and eventually will mostly scrape off with a piece of sharp wood.

 

[aquajoe]

I only use BG Products to clean engine parts or fuel systems.


Sent from my iPhone using Tapatalk

 

[barryg]

Bead blast the top crown of the piston, then put it in a pot and boil it till all the media is boiled out. Take it out and air blow it dry. This lets you make sure the crown has the proper shape with no damage. Small pieces of broken rings and even the valve can damage the top of the piston.

 

[spoon]

If you have time....soak them in straight pine-sol. Might take several days. Hit em with a brush every so often. Softens the deposits and won't discolor them.

 

[dieselyoda]

I boil my pistons in Spic-n-Span and don't worry about the crown but make sure the ring lands are absolutely clean. Don't bead blast anything except for the skirts.

 

[mwctexas]

Thanks for the info...I've got the domes and pistons looking good!...