A large V8 SI four-stroke cycle engine with displacement of 4.6 liters is equipped with cylinder cutout, which converts the engine to a 2.3 liter V4 when less power is needed. At a speed of 1750 RPM the engine, as a V8, has a volumetric efficiency of 51%, a mechanical efficiency of 75%, an air-fuel ratio of 14.5, and produces 32.4 kW of brake power using gasoline. With cylinder cutout and operating at higher speed as a V4, the engine has a volumetric efficiency of 86%, a mechanical efficiency of 87%, and uses an air-fuel ratio of 18.2. Indicated thermal efficiency can be considered the same at all speeds, and combustion efficiency is 100%. Calculate : a) Mass flow rate of air into V8 engine at 1750 RPM. [kg/sec]
b) Mass flow rate of fuel into V8 engine at 1750 RPM. [kg/sec]
c) The bsfc as V8 at 1750 RPM. [gram/kW-hr]
d) Engine speed needed as a V4 to produce same brake power output. [RPM]
e) The bsfc as V4 at higher speed. [gram/kW-hr]