Chevy Small Block Specs

The first generation of Chevrolet small-block engines powered the 1955 Chevy cars.

The Chevy small block is a family of valve-in-head V-8 engines built by the Chevrolet division of General Motors. Unveiled in 1955 models, the motors come in nine different displacements from the original 265-cubic-inch to 1970s 400-cubic-inch size. The engines share the same basic block specifications.

Original Small Block

In 1955, Ed Cole engineered a 265-cubic-inch engine that provided the basic architecture for Chevy small-block race engines until the 1990s. The motor was used in 1955 Chevy cars, including the Corvette. It had a bore and stroke of 3.75 inches by 3 inches with a compression ratio of 8:1. It generated 162 horsepower with 257 pound-feet of torque.

The 350-Cubic-Inch

The Chevy 350 small block was the standard engine of GM cars since 1967. The 350 is easily souped up and is a favorite of hot rodders and street racers. Its bore and stroke is 4 inches by 3.48 inches with a 10.25:1 compression ratio. Its power rating varied from 145 to 370 horsepower.

The 327-Cubic-Inch

The 327 was the powerhouse of the small-block family, producing 375 horsepower in its strongest factory version. The 327 powered many of the legendary GM muscle cars from 1962 until 1969. The standard 327-cubic-inch motor generated 210 horsepower with 320 pound-feet of torque. Its bore and stroke was 4 inches by 3.25 inches with a compression ratio of 8.75:1.

References

• Alabama Cooperative Extension System: The Small Block Chevy
• Classic Car Database: 1955 Chevrolet Bel Air 8 Series 2400VC
• Classic Car Database: 1968 Chevrolet Camaro V8 Series 12400
• Classic Car Database: 1969 Chevrolet Corvette Series 19400

Resources

• Circle Track: The Little Engine That Could