Between the Chrysler Slant-6 and AMC Inline-6 straight-six-cylinder engines, the Slant-6 was the first to market, with a 170 cubic-inch variant available in the 1960 Plymouth Valiant. The first ...

The popularity of various engine designs typically fades over time as technological advances provide more power, better fuel economy, or both. Flathead designs gave way to overhead valves, and ...