engine An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power ge ...

design, the penta engine (or penta head) is an arrangement of the upper portion of the

cylinder A cylinder () has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infinite ...

and valves that is common in engines using four valves per cylinder.

Design

Among the advantages is a faster burn time of the air-fuel mix. It is similar in concept to the

hemi engine A hemispherical combustion chamber is a combustion chamber in the cylinder head of an internal combustion engine with a domed " hemispheric" shape. An engine featuring this type of hemispherical chamber is known as a hemi engine. In practice, ...

, both in design and purpose, but a hemispherical cylinder head is limited to only two valves without the use of a more complex sub-rocker assembly. The four-valve penta engine design was invented by

Peugeot Peugeot (, , ) is a French automobile brand owned by Stellantis. The family business that preceded the current Peugeot companies was established in 1810, making it the oldest car company in the world. On 20 November 1858, Émile Peugeot applie ...

of France, to be first used in the 1911 Indianapolis 500 race. The penta engine (also termed pentroof combustion chamber) is the most common design used today by many manufacturers for four-valve-per-cylinder engines producing relatively high horsepower for displacement, for both racing engines and engines for passenger cars.

References

{{DEFAULTSORT:Penta Engine Internal combustion piston engines