I keep the oil off of mine as best I can, but I don't bother with trying to paint it.
I ask at least 20 out of my engines before I have to open them up, and preferably with 200K miles to go along with that. Ideally I get 20 years and 200K miles out of them without doing anything more than oil changes, plug changes and other routine maintenance, and 30 years/300K before I have to do major surgery.
Bit much to ask of engines? Perhaps. But I've already got two in the driveway that have met my minimums and still run great, so I don't see why new engines can't do it either.
I'd rather get the performance feeling when I open the secondaries than when I open the hood.