Animation: Thermodynamic processes in a four-stroke petrol engine

The animation shows the thermodynamic processes inside a four-stroke petrol engine.

The current status is marked in a PV diagram. A PV diagram (pressure-volume diagram) is used to visualise the state of a gas, in this case the air-fuel mixture in the cylinder of an internal combustion engine. The 4 cycles are marked in colour in the PV diagram. The ignition timing is also shown. The ignition point is the moment at which the air-fuel mixture is ignited in the cylinder.

If the engine speed is changed (by accelerating), ignition occurs earlier. This is due to the fact that the speed of combustion is always constant. Shifting the ignition timing ensures that the flame front hits the piston at exactly the right moment.

This relationship between engine speed, ignition timing and flame front position ensures optimum engine performance.

Overview and download

TitleThermodynamic processes in a four-stroke petrol engine
Target groupTeachers and lecturers
PlattformenMicrosoft® Windows®
Apple® Macintosh®
FeaturesFull screen mode
lossless zoom
Large screens and projection screens supported
DownloadContact us


C. Hein, S. Rikowski

Source information

  • Idea and initial concept: Tamara Riehle
  • Technical drawing of the motor: based on Ulrich Rapp (
  • Authoring tool (control elements supplied): Adobe Animate


Share the animation with your colleagues.

2 thoughts on “Animation: Thermodynamic processes in a four-stroke petrol engine

  1. Animation schaut super aus. Leider kriegt man mit dem Downloadlink die falsche Datei.
    Vielleicht können sie das noch ändern. Danke auf jeden Fall für die BEreitstellung

Leave a Reply

Your email address will not be published. Required fields are marked *