So its an A15 yes? for a start even if the crank bolts on, this B12 sounds like a 1200cc engine, so unless its a very undersquare bore, the stroke of that crank will be too short, if u r trying to creat some sort of stroker engine, it seems u r going the wrong way.

What model, year is a Sentra? I only know of Honda B series engine.
If this hasnt been done before, dont try it asit sounds like a potential parts shower.