A flat-ten engine, also known as a horizontally opposed-ten, is a ten-cylinder

piston engine A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion. This article describes the common featu ...

with five cylinders on each side of a central

crankshaft A crankshaft is a mechanical component used in a piston engine to convert the reciprocating motion into rotational motion. The crankshaft is a rotating shaft containing one or more crankpins, that are driven by the pistons via the connecting ...

. There are no known flat-ten engines which reached production. In the early 1960s, Chevrolet built several prototype flat-ten engines as part of an aborted program for family of ''Modular Engines'' to replace the Chevrolet Turbo-Air 6 flat-six engine. This development program investigated

flat engine A flat engine is a piston engine where the cylinders are located on either side of a central crankshaft. Flat engines are also known as horizontally opposed engines, however this is distinct from the less common opposed-piston engine design, ...

s with between two and twelve cylinders, with the flat-ten version being known as "P-10" ("pancake" engine). Although the program was initially intended to develop an engine for the 1964

Chevrolet Corvair The Chevrolet Corvair is a compact car manufactured by Chevrolet for model years 1960–1969 in two generations. A response to the Volkswagen Beetle, it remains the only American-designed, mass-produced passenger car with a rear-mounted, air- ...

(which is rear-engined with rear-wheel drive), the flat-ten version was fitted to an experimental 1962

Chevrolet Impala The Chevrolet Impala () is a full-size car built by Chevrolet for model years 1958 to 1985, 1994 to 1996, and 2000 to 2020. The Impala was Chevrolet's popular flagship passenger car and was among the better-selling American-made automobiles in ...

(a front-engined car which was converted to front-wheel drive).

References

Piston engine configurations 10 {{Automotive-part-stub