Good show! Sludge gets into some places where it's pretty hard to remove. I like to overfill a crankcase enough with solvent that the crankshaft counterweights and the big ends of the connecting rods splash the oil/solvent mix around like the agitator in a washing machine. 15-20 minutes at a fast idle is usually long enough to do a pretty good cleaning job. Just don't put any driving load on the rod bearings and drain the mix while it's good and hot.
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
Love your enemies and drive 'em nuts!