Chrysler didn’t invent hemispherical combustion chambers (with a crossflow-valve layout) and it wasn’t the only manufacturer to incorporate them into their cylinder-head designs. But the word “hemi” or “Hemi” is inextricably linked with the Pentastar.
Most historians trace the Chrysler hemi’s origins back to the end of World War II, when the company designed and built a thundering 2,500-hp, 16-cylinder hemi aero engine for use in U.S. fighter planes. The project never made it past the testing stage, but the seed for future Chrysler hemi performance was planted.
In the immediate postwar era, Oldsmobile and Cadillac powered to the top of the American luxury-car field behind new overhead-valve V-8 engines. Not to be outdone, Chrysler unleashed a new hemi in 1951: the 331 FirePower V-8. The FirePower made its debut in the top-of-the-line Imperial and New Yorker models—a shot across Cadillac’s bow. Then, in July of that year, it was offered in the Chrysler Saratoga, which shared a shorter, 125.5-inch wheelbase with the entry-level Windsor. The hemi-powered factory hot rod was born and it proved to be a perfect crosstown rival for the now-iconic Olds 88.
After the Chrysler hemi hit the streets, De Soto followed suit with the 276-cu.in. Firedome hemi OHV V-8 in ’52. Then Dodge delivered the 242-cu.in. Red Ram in ’53. Despite being the smallest of the lineup, Dodge’s new hemi powered Lee Petty to second-place overall in the ’52 NASCAR standings and earned him five race wins that season. Petty followed up in ’54 by taking the win at Daytona with a Chrysler hemi and winning the Grand National championship driving hemi-powered Chryslers and Dodges.
One of the greatest American performance cars of all time arrived with hemi power in 1955: the Chrysler C-300. This handsome, powerful two-door paved the way for the Letter Car era—an automotive dynasty that carried into the 21st century. In ’55 Carl Kiekhaeferprepared Chrysler C-300s showed the competition their taillamps:
