A single cylinder vertical engine has a bore of 30.5 cm, a stroke of 40 cm and a connecting rod of 80 cm long, as shown in the figure below. The mass of reciprocating parts is 135 kg. When the piston is at quarter-stroke and moving downwards from the top dead centre, the net pressure on it is 65 N/cm. The speed of the engine is 250 rpm, the turning moment on the crank shaft at that instant is .