Chrysler Slant Six Engine Overview The Chrysler Slant Six was a straight‑six engine produced by Chrysler from 1959 to 2000, introduced to replace the aging flathead straight‑six. It became one of the most iconic and reliable American small‑displacement engines of the 20th century. It was one of the most iconic engines of its day. It began life as a 225-horsepower engine but eventually wound up much less powerful than that due to the emission standards changes in the 1970s. The engine was made smaller to combat the growing threat of smaller cars from overseas and helped usher in the smaller car craze in America. There are a variety of models of the Chrysler Slant Six, as is typically the case with engines that are manufactured for more than two and a half decades. It also helped that Chrysler shoved them into everything from Dodge trucks to compact cars. Chrysler reportedly made millions of these things and put them into whatever the company could make with four wheels. While most cars lived fruitful lives, there are multiple stories online of people seeing 300,000 or more miles out of this engine. By the end of its tenure, it was still a decent engine, but the aforementioned emissions standards and the advancement of engine technology eventually rendered the slant six obsolete. Chrysler would eventually turn to other engines, which signaled the end of an era for the company. Chrysler would replace the slant six with diesel, V6, and V8 engines, although none of them became quite as well known for reliability as the slant six. Design and Naming Configuration: Inline‑six with a 30° slanted cylinder bank (reverse‑flow head). Purpose of the slant: Lowered hood profile, more compact engine bay, and better manifold runner lengths for improved torque. Naming: “Slant Six” came from Chrysler’s own press releases and ads; the 30° tilt was also called the “30‑D”. Displacements and Output 170 cu in (2.8 L): Debuted in 1960 Plymouth Valiant; ~117 hp, 155 lb‑ft torque. 225 cu in (3.7 L): Introduced in 1960; ~140 hp, 215 lb‑ft torque; replaced 170 in 1970. 198 cu in (3.2 L): Intermediate size, later phased out due to emissions. Production and Applications Cars: Plymouth Valiant, Dodge Dart, Chrysler Valiant, Barracuda, Roadrunner, and other Mopar models.
