SEVENTY YEARS OF CHRYSLER HEMI DOMINANCE AT THE TRACK AND ON THE STREET

While many manufacturers have toyed with building engines with hemispherical combustion chambers, only Chrysler has wed itself to the technology to the extent that the name "Hemi" has become synonymous with Chrysler.

- JOHNNY HUNKINS

As domestic manufacturers fought for engineering supremacy following World War II, it was Chrysler that emerged with unique research produced from an experimental inverted V16 engine with over 2,500 hp and 36 liters of displacement called the IV-2220. When mounted to the airframe of a Republic P-47D Thunderbolt, the hemispherical IV-2220 was able to sustain level flight at 504 mph at 15,000 feet. Despite this being unheard of for a prop-driven aircraft, the military contract was canceled. New-fangled jet-powered aircraft were the future, but the breakthrough engine still had a role to play, albeit in greatly modified form.

By 1949, both Cadillac and Oldsmobile had introduced new overhead-valve V8 engines, which were perceived as a premium relative to the flatheads and straight-eights of the era. Overhead V8 designs were more compact and lighter in weight, and they generated more power per cubic inch than flathead engines due to their breathing efficiency. By introducing the first production Hemi V8 in 1951 as the Chrysler FirePower V8, then in 1952 in the DeSoto as the FireDome V8, Chrysler Corporation was able to leapfrog over GM by adding another crucial technological advantage to the overhead-valve formula: the hemispherical combustion chamber. Let's look at the many Hemi engine sizes Chrysler built over the years.