Disposable paper air filters and PCV systems have more than tripled the expected life of engines. I can remember seeing the remains of Oldsmobile engines returning to Nashville from the Daytona race in the mid-1950's with half an inch of sand in the oil pan- - -that much had gotten past the piston rings after getting through an oil bath filter in 500 miles of racing on the beach.

A Detroit Diesel field engineer who was conducting a seminar for houseboat owners I attended was asked a question about "How long does a Detroit engine last?" His answer- - - -"Long enough to eat 10 pounds of dirt!" That can be 6 months, or 60 years! Keep 'em clean!
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!