Sphaera Training Systems Logo

eLearning | Computer Based Training | Systems Simulation

Sphaera Training Systems Logo

eLearning | Computer Based Training | Systems Simulation

A 4-stroke engine is an internal combustion engine (ICE) that burns a mixture of air and petrol to drive a piston and rotate a crankshaft

Unlike a 2-stroke engine, there are separate induction, compression, combustion and exhaust strokes. Therefore, a 4-stroke engine fires on every other revolution of the crankshaft.

A 4-stroke engine fires on every other revolution of the crankshaft and gets it name from the 4 separate strokes for:

  1. Induction
  2. Compression
  3. Combustion
  4. Exhaust

During the induction stroke, downward movement of the piston draws the fuel/air mixture into the combustion chamber.

Upward movement of the piston then compresses the mixture ready for the spark plug to ignite the mixture for the combustion stroke (or power stroke).

Finally, the upward movement of the piston clears the remaining gases, pushing them through the exhaust valve.

You can use the controls on the interactive animation to clearly view the working cycle of a 4-stroke engine:

Play button Press to play or pause the animation.

Step button Press to step through the animation one frame at a time!