A four-cylinder four-stroke petrol engine has a piston diameter of 80 mm, a stroke of 120 mm and a clearance volume of 100 × 10³ mm³ per cylinder. Fuel is supplied at 4.8 kg/h (calorific value 44 100 kJ/kg). In a Morse test the brake power was 14.5 kW with all cylinders working, and 9.8, 10.3, 10.14 and 10 kW with cylinders 1, 2, 3 and 4 cut out in turn. Find (a) the indicated power (kW), (b) the indicated thermal efficiency, (c) the brake thermal efficiency and (d) the relative efficiency with respect to the air-standard Otto cycle (γ = 1.4) (efficiencies in %).