<VV> Piston rings concern

[D. Monasterio]

   Every time I install rings there is a concern that comes to my mind. I know how to install them and the gaps position but, how long they will retain the original position ? Do they rotate eventually ?
   Back on the early 60s I had a German motorcycle (Durkopp, 2 cycle engine) and it had a small pin inserted in each grove of the piston to prevent rings from rotating. The ends of the rings were trimmed about half of it's wideness to allow installation with the inserted pin.
   There is enough room on a Corvair piston (1st & 2nd grooves) for the pin and trimming the ring ends looks easy.

   What do you think about ? 

   Daniel Monasterio (at home, assemblying GB engine)