$6-$ Iso$-$octane fuel $C_8{H}_{18}$ is supplied to a $4-$stroke, six cylinder spark ignition engine at $3\frac{g}{sec}.$

If the engine speed is $3000rpm,$ and the engine volume is $2000c{m}^3.$ Estimate the mass of fuel

and air entering each cylinder per cycle for excess air ratio $1\mathrm{.}2.$ Calculate also the volumetric

efficiency and the mean piston speed for $\frac{L}{d}=1\mathrm{.}2.$