General Motors will build today the 100-millionth small block V8 engine, 56 years after its introduction. The milestone engine is said to be a 638-horsepower, supercharged LS9 small block V8 normally used in the Corvette ZR1 – which is hand-built at GM’s Performance Build Center, northwest of Detroit.
The LS9 V8 is the fourth design generation of the small block V8, and is the most powerful engine ever built by GM for a regular-production car. GM will keep the engine as part of its historical collection. Other small block V8 engines are currently used in Chevrolet’s full-size trucks, SUVs and vans, mid-size trucks and the Camaro.
GM also announced Tuesday that the fifth-generation small-block under development will have a new direct-injection combustion system that will enhance efficiency over the current-generation engine. Chevrolet now sells more four-cylinder engines than V8s, and the traditional powerplant of Detroit cars and trucks is threatened with extinction as fuel economy and emission regulations become more stringent.
Introduced in 1955, the Chevy V8 reinvigorated the brand during the Eisenhower post war boom, and along with other Detroit Three dream machines reinforced American’s love of automobility that continues today.
From 1929 and 1955, Chevrolet only offered six-cylinder engines – in spite of Ford Motor’s runaway success with the Flathead V8 introduced in 1932, and Oldsmobile’s Rocket V8 of 1949. It was only in the 1950s that Chevrolet chief engineer Ed Cole set out to design a V8 that was powerful, lightweight and affordable.
Cole’s team came up with a compact, efficient 90-degree V8 engine, with overhead valves, pushrod valvetrain, and 4.4-inch on-center bore spacing. (The later production Chevrolet Big Block follows the same formula, with the exception of a wider 4.8-inch bore spacing.)
When it debuted, the Chevrolet Small Block V8 delivered 195 horsepower – ratings were liberal in those days and essentially unregulated – with an optional four-barrel carburetor. Two years after the Small Block was introduced, the addition of fuel injection increased output to 283 horsepower – or one horsepower for every cubic inch of the 283 cubic inch displacement engine. By 1970, the Chevy V8 family grew to include a staggering 450 horsepower, 454-cid Big Block.
Updated versions of the original Gen I engine are still in production for marine and industrial applications, while “crate engine” versions offered by Chevrolet Performance are used by thousands of enthusiasts every year to build hot rods. The 4.3L V-6 used in some Chevrolet and GMC full-size trucks and vans is based on the small-block, too, but with two fewer cylinders. All of these versions contribute to the small block’s 100-million production milestone.