As per my understandings, the Timely oil change is the most crucial for rings-piston than anything else. OHV or OHC comes second. A bad oil first damages the rings than any other part of an engine.
I have seen 2003 Suzuki Flash 2005 GS-150 models having sealed engines still.
I have seen 80's road masters with sealed engines still.
These all are OHC engines.