GM 1970 LS7 454 Specsby Anne Davis
In 1970, Chevrolet planned to introduce into its performance cars, especially the Corvette, a 454 cubic-inch displacement engine dubbed the LS7. This big block engine was an enlarged version of the L88, with an aluminum-head block. After the LS7's short-lived career, Chevrolet used an LS6, a less powerful 454 engine, in its performance vehicles.
Chevrolet designed the LS7 454 beginning in 1970, but it was never placed in any vehicles that were sold to the public. A Corvette with the LS7 engine was test driven by a writer for the magazine Sports Car Graphic, who reported that the car could complete the quarter-mile in 13.8 seconds at 108 miles per hour. But because of the automotive culture of the 1970s and heightened emissions standards, Chevrolet never sold the LS7 in any of its vehicles. Certain components, however, like the intake manifolds, were sold individually as performance parts.
Bore and Stroke
This engine had a bore of 4.251 inches and a stroke of 4.00 inches. The diameter of cylinders that house a moving ring-and-piston assembly is listed as the bore, while the total distance that the pistons travel inside the cylinders is listed as the stroke.
In 1970, the LS7 had a compression ratio of 11.25 to 1, a ratio that represents the capacity of the engine's combustion chamber. Higher compression ratios can produce more power. The LS7's high compression ratio meant that it could produce 465 horsepower at 5,200 rpm and 490 foot-pounds of torque at 5,200 rpm. Torque refers to the amount of work an engine can perform, and horsepower is how quickly it can perform that work.
In 1970, the LS7 had solid valve lifters and a high-performance camshaft. It featured a Holley 800CFM four-barrel fuel supply. Had it been sold to the public, it would have appeared in performance vehicles such as the Corvette.
- Thinkstock Images/Comstock/Getty Images