injector size

what mean is the BSFC ? How to calculate BSFC , Why we need to multiply by 10.2 when we want change this to cc's per minute

The answer to both of these questions is explained within the relevant modules of the course. BSFC stands for brake specific fuel consumption and the calculation requires you to know both the fuel consumption and engine power. The calculation for changing from lb/hr to cc/min accounts for fuel density when changing from mass flow to volume flow and is approximate only as it will depend on the specific gravity of the fuel and the temperature of the fuel.