The longer the better, but two or three days at a minimum. Pour 2 or 3 ounces on top of each piston and let it soak for awhile. On really tough ones, I've been able to drain the Kroil out of the oil pan after it seeps past the piston rings and pour it through again.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
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