Marchetti 8-cylinder Cam Action Engine

By Wesley Peijnenburg

The Marchetti cam-action airplane engine is based on a fascinating principle. The mechanism is inherently balanced. Rotation speed is half that of a regular radial engine because it takes half a revolution to make all cylinders complete a full stroke and return to their original position. The butterfly shaped cams act as a flywheel. Therefore rotational damping can be tuned by increasing or decreasing their weight at the cost of total engine weight. In my spare time besides my study at university I have been working on modelling, developing and building this engine. The purpose of this web page is to publish the research such that others may build and develop their own versions of the Marchetti cam-action principle. All necessary information to understand and build the engine is openly accessible and free to use. Enjoy!

1926 Marchetti Engine from Animation and comparison with a picture from

The original inventor, Paul Marchetti, unfortunately died in a tragic accident. His invention no longer had the chance of being implemented or become a success. His company was sold, drawings and prototypes have sadly disappeared.

For further information, see the sources below.

A big thank you to Bill Todd and Chuck Fellows for their help, ideas and information!

Another big thank you to Falco, my brother, who helped develop the interactive calculator and introduced me to the programming language called Elm!

Below you can see a very clear animation was made by Bill long before I started my project:
Animation of the Marchetti Engine by Bill Todd

For more information, visit:

These webpages are archived here
Animation of the CAD model by Wesley Peijnenburg

Download the instructions:

Step-by-step instructions for Solidworks: CAD_Instructions.pdf.
The X-Y-Z coordinates necessary for the cam curve: CamCoordinates.txt

Calculate your own coordinates:

You can enter the desired dimensions of your own model and calculate them with the Interactive Calculator.
Animation of the mathematical solution by Wesley Peijnenburg


Step-by-step mathematical explanation: AnalyticalDerivation.pdf.

How the mathematical solution is used to estimate the historical dimensions: Historical_Estimation.pdf.

Direct link:
Animation of the CAD model by Wesley Peijnenburg


This is my first real model of the Marchetti principle on compressed air. I am currently working on the design of a new engine.

Prototype marchetti front by Wesley Peijnenburg Prototype marchetti back by Wesley Peijnenburg

If you find these details interesting, fascinating or even useful please consider making a helpful contribution. Funds will be used to buy tools, new materials, future projects and to keep this website online:

I am currently working on both my own Marchetti engine and this website. As my next to-do's, I will add: For any kind of historical information, please visit the websites mentioned above in the section "Credits, acknowledgments and sources". If you have questions about my project or technical details, feel free to contact me at which is actually my adress. If you are working on your own cam action project, I would really love to hear about it!