In general, an American automobile engine of more than 366 cubic inches (6.0 Liters); they usually have a pushrod camshaft with intake and exhaust valves not in-line (a porcupine valvetrain). Contrast with small-block.

Big-blocks have much larger displacement and power output, but a concomitant increase in weight and overall dimensions. There's No Substitute for Cubic Inches, and big-block engines can be made to have the same efficiency as small blocks. However, they are often clumsy in stock form and they require much time, money, and expertise to exercise their full potential. Speed Costs Money (How Fast you Wanna Go?).

Popular big-blocks include