This Ferrari Patent Could Reinvent The Piston Engine

While there have been many unusual engine designs over the years, there haven't been many advancements involving the inner workings of the piston engine, except for higher-quality components, since its inception. The pistons at the heart of the typical internal combustion engine are made of cast or forged aluminum alloys that are machined into their cylindrical shape before assembly into the round cylinders of the engine block.

When the idea of internal combustion piston engines was conceived, the machines used to manufacture their components were no more advanced than the metal lathes available at Home Depot today. With basic machinery, round, cylindrical pistons and bores were the most cost-effective shapes to machine in cast-iron blocks and aluminum pistons. Today's complex machining centers can produce nearly any shape imaginable.

To that end, Ferrari's engine designers put their imaginations to work to reinvent the piston engine by incorporating oval pistons, a design AutoGuide describes as "pill-shaped," but concedes "stadium-shaped" is a more accurate geometric term. The design can be seen in Ferrari's European patent application, viewable as a PDF, filed on February 9, 2024, and published on May 3, 2025.

To spare you from the tedious jargon of the patent filing, we'll summarize Ferrari's description of its oval piston engine design. In a nutshell, Ferrari sought patent protection for the design with the long side of its oval pistons being perpendicular to the centerline of the crankshaft. An arrangement is evident in the picture above. 

Some combustion engine connoisseurs will know the Ferrari design isn't the first oval piston engine that's come to pass. While the first oval piston engine debuted in Honda's NR500 motorcycle designed to race the GP 500cc class in 1979, its piston orientation was 90 degrees to Ferrari's design, with the long axis of the piston parallel to the motorcycle's crankshaft.

The orientation of the oval pistons is an important aspect of the Ferrari design. The shorter dimension of the oval pistons running parallel to the crankshaft allows the entire engine to be shorter. Automakers have employed various methods to shorten the length of engines with double-digit cylinder counts over the years. Bugatti's W-16 engine is just one example.

The Ferrari patent filing describes the proposed design as having "at least two cylinders," while the drawing clearly depicts a V-12 configuration. Besides the oval pistons, the design uses "directly coupled ... coplanar" connecting rod pairs between the crankshaft rod journal and two opposing pistons, further reducing the engine's footprint.

While Ferrari's oval piston engine design is an interesting advancement to the piston engine, it remains to be seen if it comes to reality. There's no doubt that Ferrari has the technology to build such an engine, but car companies often patent exotic ideas with no intention of bringing them to life.