Automobile Engines — Winter 2020

Define (1) Swept volume with SI Unit (2) Clearance Volume with SI Unit (3) Compression ratio with expression

Describe factors influencing firing order of SI engine.

Explain valve timing diagram of SI and CI 4-stroke engine with neat.

Give assumptions are made for analysis of single jet carburetor.

Explain in brief working principle of venture in context to carburetor.

Explain A/Fratio in various operation ranges of carburetor for SI engine during transient operation.

Give objectives of injection system of CI engine.

Explain terms atomization and turbulence in context to CI engine injection system.

Give type of solid injection system. Explain common rail injection system with suitable sketch.

Describe in brief knocking phenomenon.

Explain the role of Ethylene glycol in the coolant.

Describe with neat sketch water cooling system with thermostat valve.

Give the function of lubrication system.

Explain parameters viscosity, pour point, oxidation stability, oiliness in context to lubricating oil.

Asingle cylinder 4 stroke cycle oil engine works on diesel. The following reading were taken when the engine was running at full load Mean effective pressure = 7.5 bar Speed of the engine = 400 rpm Brake Power = 8 kj/s Fuel consumption= 2.8 kg/hr Calorific value of fuel = 42000 kj/kg Diameter of the cylinder = 16 cm Stroke length = 20 cm Estimate: Friction power, Mechanical efficiency, Brake thermal efficiency, Brake mean effective pressure.

What is scavenging?

Describe concept of supercharging.1

Differentiate between Mist and Pressure feed lubrication system.

What is valve overlapping? Give significance of it.

Compare brake power, friction power and indicated power of an IC engine.

Explain combustion phenomenon of SI using pressure-theta (Crank angle) diagram with stages.

Define (1) Volumetric efficiency with expression (2) Friction power with SI Unit

Explain turbocharger with neat sketch.

Explain heat balance in details.