History of the Buick and Oldsmobile 455 Enginesby Rob Wagner
The Buick and Oldsmobile 455-cubic-inch V-8 engines are separate powerplants produced by the two automakers under the General Motors umbrella. Each featured different bore and stroke dimensions and horsepower ratings. The two 455s were clearly Buick and Oldsmobile's answer to the muscle car rate of the 1960s and early 1970s, but neither automaker received credit for producing performance street cars. Rather, Chevrolet's more popular 454 and Chrysler's 427 Hemi V-8s overshadowed the 455s.
Buick and Olds in the 1960s
Chevrolet's Chevelle, El Camino and Camaro, and the Ford's Mustang, Torinos and Mercury Cougar received the lion's share of credit for producing performance cars. Rounding out the field were the Hemi-powered Dodge Chargers and Plymouth 'Cudas. Chevys were equipped with the 396 and 454 V-8s, while Ford and Mercurys received the 351 and Boss 302. These cars emerged as icons in the muscle car era because of their sporty bodies and sport-tuned Super Sport, Shelby and Mopar performance packages. Buick and Oldsmobile were different kettles of fish. They were high-end luxury-oriented with a reputation as a car for the grandparents. Yet the Buick Riviera, Gran Sport and Wildcat, and the Oldsmobile 4-4-2 and Toronado matched their competitors in raw horsepower.
Buick produced its 455-cubic-inch V-8 from 1970 to 1976. The 455 came to be after General Motors lifted its ban on equipping intermediate cars with V-8s larger than 400 cubic inches. Based on the 400 and 430 V-8s, the Buick 455 had a 4.31-inch bore and 3.90-inch stroke. The standard 455 wielded 350 horsepower and the performance Stage 1 version developed 370, although testing on many Buick 455s put the horsepower rating closer to 425. However, what made the 455 special was its torque rating of 510 foot-pounds, more than any other engine on the road in 1970.
Buick 455 Performance
The 1970 Riviera's 455 generated 370 horsepower to achieve 0 to 60 mph in 7.9 seconds and the quarter mile in 17 seconds. The glory period was short-lived. Tighter emission control standards and high insurance premiums in 1971 forced Buick to detune the engine to 315 horsepower in the Riviera and 330 on the Gran Sport models. The 330-horsepower 455-equipped Gran Sport clocked 0 to 60 mph in 8.1 seconds. By 1975, the 455 generated only 205 horsepower.
Oldsmobile's 455 was produced from 1968 to 1976 as the Rocket 455. It featured a 4.126-inch bore and 4.25-inch stroke. Oldsmobile had cheated the 400-cubic-inch GM ban in 1968-1969 by offering it as an underpublicized Hurst/Olds option on the 4-4-2 models. The optional Olds 455 powered the 4-4-2, Cutlass Custom Cruiser, Delta 88, 98 Luxury models and the Toronado.
Olds 455 Performance
The Rocket 455 featured a 10.25-to-1 compression ratio and four-barrel Rochester carb with the standard models developing 350 horsepower and 440 foot-pounds of torque. The performance W-30 package was for the Cutlass models. The W-30 455 was equipped with a performance carburetor, hotter cam and Force Air induction, thanks to a pair of hood scoops on a fiberglass hood, to wield 370 horsepower and 500 foot-pounds of torque. The W-30 455 reached 0 to 60 mph in 5.7 seconds and the quarter mile in 14.2 seconds. In 1973, horsepower dropped to 250.