$7-$ Find the brake power for a $4-$stroke $6-$cylinder diesel cycle engine at $1500rpm$ with a

mechanical efficiency of $0\mathrm{.}85,$ and specific fucl co:sumption $245\frac{g}{b}kW.hr.$

The fucl used is $C_8{H}_{16},$ volumetric efficiency is $80\%$ at $1$ bar and $27C.$ Take $\frac{L}{d}=1\mathrm{.}2,L=0\mathrm{.}1$

$m,$ and calorific value $=42M\frac{J}{k}g.$ Calculte, also, inchicaled ther mal efficiency.