Engine challenge

Build the four-stroke cycle.

Put the engine’s four jobs in order. Move a card, then watch your progress.

Open Engine Lab
One cycle · two crankshaft turns

What happens first?

0 of 4stages in the right spot
  1. Push down

    Power

    A spark ignites the mixture. Expanding gases push the piston down.

  2. Breathe in

    Intake

    The intake valve opens. The piston moves down and draws in air and fuel.

  3. Breathe out

    Exhaust

    The exhaust valve opens. The piston moves up and pushes used gases out.

  4. Squeeze it

    Compression

    Both valves close. The piston moves up and squeezes the mixture.

Move any card to get instant feedback.There is no timer and wrong moves do not cost anything.