Valve Timing Diagram for a 4-stroke cycle C.I (Diesel) Engine

The Diesel engines are also known as compression ignition (C.I) engines. The valve timing diagram for a 4-Stroke cycle diesel engine is shown in below.

The following particulars are important for a four stroke cycle diesel engine regarding valve timing diagram:

• T.D.C - Top dead center

• B.D.C - Bottom dead center

• I.V.O - The Inlet valve opens at 10^o - 20^o before T.D.C

• I.V.C - The Inlet valve closes at 25^o - 40^o after B.D.C
• F.V.O - The Fuel valve opens at 10^o - 15^o before T.D.C
• F.V.C - The Fuel valve closes at 15^o - 20^o after B.D.C
• E.V.O - The Exhaust valve opens at 30^o - 50^o before B.D.C
• E.V.C -  The Exhaust valve closes at 10^o - 15^o after T.D.C

Important Notes:

(i) In diesel engines, the fuel is injected in the form of very fine spray into the engine cylinder, which gets ignited due to high temperature of the compressed air.