The life of engine is not depending on material of sleeve ( AAC state that AL piston/Al sleeve and C-chrome plating on sleeve), so basecaly in AAc motor piston still running on chrome, the same as ABC or BRB. AAC is much better construction due to it's phisical properties, but it has some issue, but beside that issue it last absolutly the same. Life of p/s set is only depending on chemistry of piston material and care of racer. AAC required more carefull handeling and more complecated in production.
BTW, I have never heard any NSR with AAC sets in it. Will be very interesting to see it-any pics? Please.
Edward