i had a set off itr std nippon piston well i just messed up one or the oil ring well i had a set of itr 81.5 mm piston ring laying around will this work on a 81 mm piston please help i know this is a dumb ? but i have to ask

 

How did you mess it up? The oil rings only have a minimum spec.
And by oil ring you mean the very bottom rings right? Just need to confirm.

 

no, it will not work. just get a set specifically for the size of the bore.