Requirements for Multiengine Rating:

Depending on the student's background, the multi engine training will typically require 2 - 3 hours ground training and approximately 8 - 10 hours flight training for a VFR only rating. To prepare for a IFR multi engine rating up to four more hours of training are necessary.

more information about the instruction and the training airplane:

Multi Engine Instruction and Maneuver Guide
Airplane and System Description for Cessna310R