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A four stroke diesel engine has

A four stroke diesel engine has Correct Answer Two valves

Explanation:

There are two types of valves in an engine cylinder - Inlet Valve and Exhaust Valve.

To produce power in a four-stroke engine the following operations take place in the sequence given.

Suction stroke

  • The piston moves from TDC to BDC. A vacuum is created inside the cylinder. The inlet valve opens while the exhaust valve remains closed. The charge (air/air-fuel mixture) enters the cylinder.

Compression stroke

  • The inlet valve closes. The exhaust valve remains closed. The piston moves from BDC to TDC. The charge (air/ air-fuel mixture) is compressed. The pressure and temperature rise.

Power stroke

  • S.I Engine: The charge is ignited and pressure develops inside the cylinder. The gas expands and the piston is forced down from TDC to BDC. Both the valves remain closed.
  • C.I Engine: At the end of compression stroke diesel fuel is injected into the hot compressed air in the combustion chamber; result in instances burning of diesel with an explosion the gas expand for is the piston down and power is produced and pressure develops inside the cylinder. The gas expands and the piston is forced down from TDC to BDC. Both the valves remain closed. Power is supplied to the flywheel.

Exhaust stroke

  • The inlet valve remains in the closed position. The exhaust valve opens, the piston moves from BDC to TDC due to the energy stored in the flywheel. The burnt gases inside the cylinder go out through the exhaust valves. At the end of the stroke, the exhaust valve closes.

The cycle of suction, compression, power/expansion, and exhaust are repeated. In this type of engine, one power stroke is obtained in two revolutions of the crankshaft. Power is supplied to the flywheel.

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