come on now! I'm really suprised that this theard has gone three pages. Modern engine oils have enough detergent in them to wash a hog for a date at the county fair.
Back in the fifties engine sludge might well have been a problem in the old 53 Chey grain truck that got run only in the fall and had it's oil changed every leap year.
Lifters have very close tolerances and they can GO BAD.....I don't put ketchup on Samlon no matter how many adds Hines puts out proclaiming
it as a gourmet delight, nor do I put snake squeezings in my beautiful Mercedes engines....