A spark ignition engine of four-cylinder four-stroke cycle of a bore=88mm and a stroke of 84mm produce a torque of 160 N.m at 2200 rpm. The specific fuel consumption is 0.370 kg/kW.hr , the air fuel ratio is 18.5:1 and the LCV= 44500 kJ/kg. Determine:- 1-the brake power 2-the brake thermal efficiency 3-the volumetric efficiency if Pa= 1.0132 bar and Ta=310 K 4-the mean piston speed