Atkinson cycle

THE ATKINSON CYCLE

the Atkinson cycle significantly improved the fuel-efficiency of a four-stroke spark ignition engine through one particularly ingenious modification.

The four basic phases of the Otto cycle remained but Atkinson introduced a new timing sequence to delay the closing of the intake valve during the compression stroke. Keeping the intake valve open slightly longer effectively reduced the engine’s displacement during the intake cycle but retained the full ratio of expansion in the combustion or power stroke.

In simple terms, the Atkinson cycle was designed to minimise the use of fuel during the intake stroke yet exploit the part of the cycle that generates power.

All explained in the video below:

  https://youtu.be/uhtMEvfZkdM