The L78 was a

Big-Block A V8 engine is an eight-cylinder piston engine in which two banks of four cylinders share a common crankshaft and are arranged in a V configuration. The first V8 engine was produced by the French Antoinette company in 1904, developed and use ...

engine produced by

Chevrolet Chevrolet ( ), colloquially referred to as Chevy and formally the Chevrolet Motor Division of General Motors Company, is an American automobile division of the American manufacturer General Motors (GM). Louis Chevrolet (1878–1941) and ous ...

between 1965 and 1970. Rated at for its first year, the rating dropped to in subsequent years (although there was no change in power). Between 1966 and 1969 it was the most powerful

Regular Production Option A Regular Production Option (RPO) is a General Motors standard coding for vehicle configuration options and began in 1970. These codes are a combination of 3 alphanumeric characters and refer to a specific option or modification to the vehicle inc ...

engine available in Chevrolet's intermediate line, making it a highly-collectible

muscle car Muscle car is a description according to ''Merriam-Webster Dictionary'' that came to use in 1966 for "a group of American-made two-door sports coupes with powerful engines designed for high-performance driving." The '' Britannica Dictionary'' ...

engine today.

History

The second-generation Chevrolet Big-Block engine was introduced at the 1963 Daytona 500 as the Mark II. The block entered production in mid 1965 as the Mark IV "Turbo-Jet," phasing out the first-generation W-series Big-Block. In its first year the 396 was available as the L78 option in

Corvettes A corvette is a small warship. It is traditionally the smallest class of vessel considered to be a proper (or " rated") warship. The warship class above the corvette is that of the frigate, while the class below was historically that of the sloop ...

and full-sized (

Impala The impala or rooibok (''Aepyceros melampus'') is a medium-sized antelope found in eastern and southern Africa. The only extant member of the genus '' Aepyceros'' and tribe Aepycerotini, it was first described to European audiences by Germa ...

, Bel Air, Biscayne) models, and as the L37 in the intermediate ( Chevelle) model. These engines differed only in that the L78 had a solid-lifter

camshaft A camshaft is a shaft that contains a row of pointed cams, in order to convert rotational motion to reciprocating motion. Camshafts are used in piston engines (to operate the intake and exhaust valves), mechanically controlled ignition systems ...

, while the L37 had a hydraulic lifter cam shaft. In 1966 the L78 was available exclusively in the intermediate line. For 1967 the engine was additionally available in Chevrolet's new

pony car Pony car is an American car classification for affordable, compact, highly styled coupés or convertibles with a "sporty" or performance-oriented image. Common characteristics include rear-wheel drive, a long hood, a short decklid, a wide range ...

, the

Camaro The Chevrolet Camaro is a mid-size American automobile manufactured by Chevrolet, classified as a pony car. It first went on sale on September 29, 1966, for the 1967 model year and was designed to compete with the Ford Mustang. The Camaro share ...

. The following year the motor became available in the compact

Chevy II The Chevrolet Chevy II/Nova is a small automobile manufactured by Chevrolet, and produced in five generations for the 1962 through 1979, and 1985 through 1988 model years. Nova was the top model in the Chevy II lineup through 1968. The Chevy II ...

also. For the 1970 model year the 396 was bored , resulting in a engine. Despite this, the motor was still badged as a 396. 1970 was also the final production year for the L78. Although 1970 LS6 Chevelles are generally more collectible today, 1970 L78 Chevelles are in fact rarer (4,475 units versus 2,144). Between 1966 and 1969 the L78 was the highest-horsepower engine available in Chevrolet's intermediate line via a Regular Production Option (RPO). Despite this, in 1969 an L72 , engine could be ordered in an intermediate via a Central Office Production Order (COPO). This option bypassed a rule that existed prior to 1970 wherein intermediate models were restricted to engines with displacements less than . Only 323 of these cars were produced. With the lifting of the restriction in 1970 and the introduction of the 454, the COPO option in Chevelles was discontinued.

L89

A version of the L78 was also produced with aluminum cylinder heads and sold as RPO L89. This option did not change performance, but reduced engine weight by roughly . This engine was available from 1968 to 1970.

Production numbers

L78

* * 54 of these were converted into L72 Yenko Super Camaros. * ** 64 of these were converted into L72 Yenko Super Camaros.

L78/L89

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References

*DeMauro, Thomas A. "Simultaneous Combustion - 1967 Chevrolet Chevelle SS L78: How a 1967 Chevelle SS L78 396/375-hp tribute project led to restoring a numbers-matching original--at the same time." In ''Hemmings Muscle Machines''. August 2014. *Niedermeyer, Paul. "1965 Chevelle SS396 Z16: 201 Built, And A Common 396 Engine Misunderstanding Finally Resolved." In ''Cubside Classic Online.'' http://www.curbsideclassic.com/blog/1965-chevelle-ss396-z16-201-built-and-a-common-396-engine-misunderstanding-resolved/. *Zazarine, Paul. "1969 L78 SS396 Chevelle - The Factory's Fastest." In ''Super Chevy Online''. http://www.superchevy.com/features/sucs-0732-1969-chevelle-l78/. Chevrolet engines V8 engines Gasoline engines by model Regular Production Option