I have seen some 2 strokes you can eat off of. Takes a loving a knowledgeable person to accomplish it. Actually there is a video on my channel of a tour of a bus like that. It was a 4106 owned by an older gentleman that put a lot of care into his coach.

@@ThisOldBus i should’ve been more clear in my comment and for that I apologize. I look at them from a commercial standpoint and running engines commercially as I do no downtime is the name of the game. If you’re going to run a piece of equipment enough to make a decent profit you don’t have time to chase things like leaks. Basic maintenance like fluid/filter changes have to suffice many times. In those situations a Detroit 2-stroke will be an oily mess after being run hard for an extended time. On the flip side a 4-stroke Detroit or Cat will run much “dryer” during the same period. For you guys running motor coaches as RVs it’s much easier to pull them off the road and fix seeps and leaks as they occur. My first commercial motor coach had a Detroit reman 6V92T in it. I absolutely loved hearing it scream down the interstate. I didn’t love the added maintenance trying to keep the drip, drip, drip to a manageable level.