End of the line for the Chevy Big Block

After a production run that lasted over 50 years the end of 2009 was also the end of production for the Chevy Big Block. Produced at GM’s Tonawanda plant there were 5 million Chevy Big Blocks made during this time, with the final engine being signed by all the workers. This final engine is to be kept for the GM Heritage Centre.

The Chevy Big Blocks were a range of large displacement V8’s originally developed in the late 50’s to keep pace with the demand for increased power and torque, a necessity with the ever increasing size and weight of the cars and trucks of the time.

Production of the Chevy Big Block started in 1958 with the “W” series or “Turbo Thrust”. Staring with a 348ci with 4 barrel carburetor, it was also produced in 409 and 427ci capacity.
Ashington 2009
By the mid 1960’s further development of the engine saw a second generation (Mark IV) or “Rat Motor” (as it became known), with modification to the valves and combustion chambers giving improved volumetric efficiency at high rpm’s, improving power output. This version making its debut in Chevrolets 1963 record-setting stock cars, and was marketed in sales literature as the “Turbo-Jet V8”.

Whilst available as a 366ci, this was only fitted to trucks and buses. It was the 396 & 402ci versions that found their way into the Corvette, Chevelle, Camaro, Nova, Monte Carlo, Impala, Bel Air and Caprice. In 1966 the 427ci version was produced, and it stayed in production until the mid 1990’s, although this was through commercial vehicles.

In 1970 the engine was increased again for the Chevrolet Corvette, 454ci (7.4 litre), but the true potential was short lived. As the 1970’s progressed the power was gradually reduced, and the introduction of unleaded fuel required hardened valve seats to compensate for the lack of protection previously given by the lead. 1974 was the final year that the Corvette was offered with a 454ci, with the Chevelle carrying it through to the middle of 1975.

The L18 was the most recent Big Block made at the plant, but only accounted for about 3% of the plant production despite the aftermarket, commercial and marine applications. Unfortunately 150 workers will be out of work with the demise of this engine, whilst 4 and 5 cylinder engines will still be produced there at the plant. There is hope that an alternative opportunity will present itself to offer employment in the area soon.

The versatility of these engines meant they were being used for power generation, powering pumps, power boats etc and it was this following outside the auto industry that helped ensure the long history it has enjoyed to date – it now down to us to help the Big Block to live on!