User blog comment:Shinhwalee/Guide to Power Leveling Heavy Cruiser (CA) in World 3-2A/@comment-28129513-20160901180130/@comment-232062-20160904030340

Uhh.. assuming you can make that CA get Srank MVP everytime it would take exactly as long as any other ship doing the same thing on the same map..You said you haven't done it for CAs, so one would assume you've done it with BBs or CVs.. it's the same amount of xp so...

As far as howmany days/weeks, well no one can tell you that, it's not like we know how much playtime you have. Just look at Experience and Rank figure out how much xp you need, how much you get for FSMVP Srank, how long a run takes, and jam those numbers in a calculator to figure out how many hours of grinding it would take and then spread that out over however much time you actually have to gind and voila....