Aviation Training Systems

4-Stroke Engines

A 4-stroke engine 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.


How Does a 4-Stroke Engine Work?

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.


Use the controls on the left to clearly view the working cycle of a 4-stroke engine.

Press the upper PLAY button to play or pause and use the lower STEP button to step through the animation one frame at a time!.


More Animations

If you are an instructor and you need animation like this for your school, why not contact us for a cost-effective quotation. A range of ready made training material is available for purchase online via our products list.

For more information on other types of internal combustion engines see:




For more information on instrument trainers or training material for specific systems, click on the links below: