Hemi Engine - Technology and Implementation

Technology and Implementation

With the hemispherical combustion chamber design, the intake and exhaust valves are on opposite sides of the chamber, sending the combustion mixture flowing directly across the chamber. This design is commonly referred to as a "cross-flow" head. Significant challenges in the commercialization of engines utilizing hemispherical chambers revolved around the design of the valve actuation, and how to make it effective, efficient, and reliable at an acceptable cost. This complexity was referenced early in Chrysler's development of their 1950s hemi engine: the head was referred to in company advertising as the Double Rocker head.