INTERNAL COMBUSTION ENGINES Four Stroke Cycle Otto Cycle

INTERNAL COMBUSTION ENGINES

Four Stroke Cycle – Otto Cycle

Starting position, intake stroke, and compression stroke.

Ignition of fuel, power stroke, and exhaust stroke.

Four Stroke Cycle – Diesel Cycle

Two Stroke Cycle – Otto Cycle

Comparison of 4 - stroke & 2 - stroke Engines • To produce same power 2 stroke cycle engine will be of less weight and space • More uniform turning moment in 2 stroke cycle engine • Since no valve in 2 stroke cycle engine more mechanical efficiency, simple construction, low initial cost, power saving… • Fuel consumption is increased in 2 stroke cycle engine

Comparison of 4 - stroke & 2 - stroke Engines • Two-stroke engines don't last nearly as long as four-stroke engines due to the lack of a dedicated lubrication system. • Two-stroke engines produce a lot of pollution due to the combustion of the oil and due to the fact that each time a new charge of air/fuel is loaded into the combustion chamber, part of it leaks out through the exhaust port.

Fuel Supply – Fuel injection in Diesel Engines

Fuel Supply - Carburetion in Petrol Engines

Different Systems in IC Engines • Ignition System in Petrol Engines • Cooling System in IC Engines • Lubrication System in IC Engines – Splash Method – Pressure feed Method – Properties of Lubricants: Viscosity, Not vaporizing at operating temperature range, High specific heat, Good cohesive and adhesive qualities

MPFI Engine