In general, an American automobile V-type engine of eight cylinders and 270 to 360 cubic inches displacement (4.4 to 6.0 Liters). They usually have shared crank journals and a pushrod camshaft with intake and exhaust valves in-line. Contrast with big-block. (NB: The largest members of a small-block line can be up to 400 cubic inches, bigger than some big-blocks (see the Chevy 400)).
Small-block engines usually have better price-performance and performance to weight ratios -- Speed Costs Money (How Fast you Wanna Go?). Especially in stock form, they generally have better volumetric, mechanical and thermal efficiency. But then again, There's No Substitute for Cubic Inches.
Popular small-blocks include