The above post is only a little tongue in cheek...
A long time back we had an engine builder who put a 4.2 Sachs on a test stand and ran it for 24hr a day for 30 days (720hr). They used dino oil at 40:1 and a servo driver on the throttle. After 30 days they tore it down and measured things.
Main bearings... with in specs for new parts
Rod bearings.... within specs for new parts
Cylinder.... just within specs for new parts
Piston.... just outside specs for new parts
Ring ..... with in useable specs, estimated life to replacement would be due was an addational 250-300 hr.
The Sachs engines were/are rated at 1000 hr, so these numbers back that up.
All these endless post about oil is people who should be out flying instead of wasting time on the internet..... good clean oil, clean gas and learn how to fly the sucker. Dont crash and these "old not state of the art industrial " engines will last a life time.