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Cleaning Cylinder Walls

The biggest problem with taking a head off is getting dirt down around the piston top by the ring lands.   In the old days when you did valve jobs every 40,000 or 50,000 miles the rings would fail shortly after a valve job.   The major cause was dirt that got down beside the piston top where it is nearly impossible to get it out.

Here's the trick I use when I pull a head.   After you've scraped the deck, use a shop vacuum to get the dirt out of the cylinder, especially at the top of the pistons.   I wipe up as much as I can then use the shop vac (with a plastic tip) to suck up any dirt from around the edge of the pistons.   (I use a crevice tip that way the suction is higher per square inch of opening and the plastic part won't scratch the cylinder wall or piston as easily.)   I then wipe the cylinder walls again with a WHITE, very lightly oiled rag and turn the engine over slowly by hand (you don't want the cylinder walls to be dry but you also don't want so much oil that the oil will get pushed past the top ring).   As each piston gets to the top I use the vac to suck out any dirt around the edges of the piston and then wipe the top inch or two carefully when the piston has gone back down into the cylinder.   I continue to do this until the rag comes out clean.   I often use several rags but I don't stop until the rag shows no traces of dirt.

I never had a set of rings fail after I pull a head when I clean the cylinders this way.