The Chevrolet small-block engine is a series of automobile V8 engines built by the Chevrolet Division of General Motors using the same basic small (for a V8) engine block. Retroactively referred to as the "Generation I" small-block, it is distinct from subsequent "Generation II" LT and "Generation III" LS engines. Engineer Ed Cole, who would later become GM President, is credited with leading the design for this engine.
Production of the original small-block began in the fall of 1954 for the 1955 model year with a displacement of 265 cu in (4.3 L), growing incrementally over time until reaching 400 cu in (6.6 L) in 1970. Several intermediate displacements appeared over the years, such as the 283 cu in (4.6 L) that was available with mechanical fuel injection, the 327 cu in (5.4 L) (5.3L), as well as the numerous 350 cu in (5.7 L) versions. Introduced as a performance engine in 1967, the 350 went on to be employed in both high- and low-output variants across the entire Chevrolet product line.
Although all four of Chevrolet's siblings of the period (Buick, Cadillac, Oldsmobile, and Pontiac) designed their own V8s, it was the Chevrolet 350 cu in (5.7 L) small-block that became the GM corporate standard. Over the years, every American General Motors division except Saturn used it and its descendants in their vehicles.
Finally superseded by GM's Generation II LT and Generation III LS V8s in the 1990s and discontinued in 2003, the engine is still made by a GM subsidiary in Mexico as an aftermarket replacement. In all, over 90,000,000 small-blocks have been built in carbureted and fuel injected forms since 1955. In many respects, the later Generation II and Generation III engines still in production today for various vehicles still trace some of their design lineage to the "small block" design concept first laid down by Ed Cole and his team.
The small-block family line was honored as one of the 10 Best Engines of the 20th Century by automotive magazine Ward's AutoWorld.
The Chevrolet 90-Degree V6 engine, which is still in production, is this original small-block (and NOT the newer LS1) but minus cylinders #3 and #6
It was, however, the 350 cu in (5.7 L) series that came to be the best known Chevrolet small block. The engine's oversquare 4.00-inch bore and 3.48-inch stroke (102 mm by 88 mm) are nearly identical to the 436 hp (325 kW) LS3 engine of today, but much has changed. Installed in everything from station wagons to sports cars, in commercial vehicles, and even in boats and (in highly modified form) airplanes, it is by far the most widely used small-block of all-time.
Though not offered in GM vehicles since 2004, the 350 cu in (5.7 L) series is still in production today at General Motors' Toluca, Mexico plant under the company's "Mr Goodwrench" brand, and is also manufactured as an industrial and marine engine by GM Powertrain under the Vortec name.
From 1955–74, the small-block engine was known as the "Turbo-Fire V8".