Pent-roof combustion chamber
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In engine design, the penta engine[citation needed] (or penta head) is an arrangement of the upper portion of the cylinder and valves that is common in engines using four valves per cylinder.[1]
Design
[edit | edit source]Among the advantages is a faster burn time of the air-fuel mix.[2]
It is similar in concept to the hemi engine, 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 of France,[citation needed] to be first used in the 1911 Indianapolis 500 race.
The penta engine (also termed pentroof combustion chamber) is the most common design[citation needed] used today[when?] by many manufacturers for four-valve-per-cylinder engines producing relatively high horsepower for displacement, for both racing engines and engines for passenger cars.