@Hemi The HEMI engine, short for Hemispherical combustion chamber, is a high-performance engine design known for its power and efficiency. Popularized by Chrysler, it features a domed cylinder head that allows for larger valves and better airflow. First introduced in the 1950s and famously revived in muscle cars of the 1960s and 70s, the HEMI remains a symbol of American automotive engineering and raw power, especially in Dodge’s performance vehicles.