Two identical petrol engines having the following specifications are used in vehicles:
Engine 1 : Swept volume = 3300 cc, Normally aspirted, bmep = 9.3 bar, rpm = 4500, Compression ratio = 8.2, Efficiency ratio 0.5, Mechanical efficiency = 0.9, Mass of the engine = 200 kg.
Engine 2 : Super charged, Swept volume = 3300 cc, bmep = 12.0 bar, rpm = 4500, Compression ratio = 5.5, Efficiency ratio = 0.5, Mechanical efficiency = 0.92, Engine mass = 220 kg.
If both the engines are supplied with just adequate quantity of petrol for the test run, determine the duration of test run so that the specific mass per kW of brake power is same for both the engines. Calorific value of petrol = 44000 kJ/kg.
Assume both the engines operate on four stroke cycle.
Also compare two engines and suggest their applications with reasoning.