502 Engine Specsby Anne Davis
The 502 is a member of Chevrolet's big-block engine family. First manufactured in the late 1970s, this eight-cylinder engine was placed in Chevy and GM service vehicles until the early 1990s. After production ceased, the manufacturer offered this engine as a crate engine, meaning that consumers could build the engines themselves from the parts. Because of its many applications, this engine has a wide range of output capabilities.
Displacement, Bore and Stroke
This Chevrolet big-block engine has a displacement of 502-cubic-inches, or 8.2 liters. It has a bore of 4.47 inches and a stroke of 4.00 inches. Because displacement measures the quantity of air displaced inside the cylinders by the pistons and is a general indicator of an engine's size and power capabilities, bore and stroke have a direct effect on the engine's output. Bore refers to the diameter of the cylinders and stroke is the distance the pistons, which operate inside the cylinders, travel from top to bottom. Larger bore and stroke values result in larger displacement, which in turn leads to a potential for higher power output.
Depending on its application, the 502 engine had an output rating between 338 and 502 horsepower and from 470 to 567 foot-pounds of torque. Its 9.6-to-one compression ratio assists in this high output. Compression ratio is the ratio between the largest air capacity inside the cylinders and the smallest. Higher compression ratios, like that of the 502, result in higher torque, an engine's ability to do work, and higher horsepower, a rate-based measurement of how quickly an engine can perform.
The 502 is constructed within a cast iron block with four-bolt main caps. It has eight cylinders constructed inside an aluminum oval port. Its intake valve sizes are 2.19 inches for the intake and 1.88 inches for the exhaust. This engine's crankshaft and connecting rods are made of forged steel and its pistons are of forged aluminum. The manufacturer recommends fuel with a 92 octane rating.