The History of the 454ci Engineby Rob Wagner
The Chevrolet 454-cubic-inch V-8 engine was part of the Mark IV big-block V-8s that competed against Chrysler's 426 Hemi for muscle car supremacy. Chevy launched the Mark IV V-8s in 1965, but the 454 didn't arrive until 1970. And its timing couldn't have been worse. The 454 wielded massive horsepower and torque for two years before General Motors detuned its engines beginning in 1972 to accommodate stricter federal emissions and safety standards.
The 1970 debut of the 454 was Chevrolet's effort to raise the bar in muscle car performance. Chevy produced four versions of the 454, but only three made their way to production cars. The base 454 was the LS5 that powered Corvettes, Camaros and Chevelles. It also powered station wagons and the Chevy C/K series light-duty pickups. The LS6 was a high-performance 454 option. The LS7 never saw production for standard Chevys, but was a crate, or replacement engine, for custom Chevys and tuned to deliver as much as 500 horsepower. The LS7 was still available in 2011. The detuned LS4 454 powered the 1973 and 1974 Monte Carlos, Chevelles and Corvettes.
All 454s had a 4.251-inch bore and 4-inch stroke. The 1970 LS5 featured a four-barrel carburetor and 11.25-to-1 compression ratio to deliver 360 horsepower for the Chevelle and 390 horsepower for the Corvette. The torque rating for both cars was 500 foot-pounds. In 1971, the Chevelle's LS5 equipped with a four-barrel car developed 364 horsepower and 465 foot-pounds of torque. Horsepower dropped dramatically in 1972 to 270 with a 390 foot-pound torque rating as automakers switched from "gross" horsepower ratings to "net" horsepower and emission control requirements began to kick in. In 1974, the LS5 could no longer sustain itself as an engine capable of efficiently delivering massive horsepower. It only generated 235 horsepower and 295 foot-pounds of torque when small-block V-8s could deliver the same horsepower in a much smaller package.
The high-performance LS6 454 equipped with a four-barrel carb had an 11.25-to-1 compression ratio and wielded 450 horsepower and 500 foot-pounds of torque in the 1970 Chevelles and Camaros. Chevy slightly detuned the 1971 version to generate 425 horsepower and 475 foot-pounds of torque. The automaker ceased production of the LS6 after 1971.
For 1973, the LS4 arrived for a brief stay to power the Chevelle, Monte Carlo and Corvette. It generated 275 horsepower and 395 foot-pounds of torque. The 1974 versions featured a 235-horsepower engine for the Monte Carlo and Chevelle, while a 270-horsepower version came with the Corvette.
The 454 posted some impressive times even when it lost horsepower as the 1970s wore on. A Chevelle equipped with the LS6 450-horsepower 454 reached zero to 60 mph in 6.1 seconds and the quarter mile in 13.7 seconds at 103 mph. The LS6 365-horsepower 454 managed a 6.0-second zero-to-60 clocking in the 1971 Chevelle, but struggled to obtain 14.35 seconds in the quarter mile test. The 1971 Corvette equipped with a 425-horsepower 454 achieved 60 from a dead stop in 6.5 seconds and the quarter mile in 14.4 seconds.