In the early 1950s, Chrysler released a new engine design that would end up taking the automotive world by storm. It was a relatively standard V8 engine block but it had a new type of cylinder head design and valve train layout. This new engine came to be called a “Hemi” because the combustion chamber head was hemispherical (semi-circular) in shape. Chrysler’s first version of the Hemi engine displaced 331 cubic inches and offered the highest horsepower to weight ratio being made.
A few years later, in 1955, Chrysler debuted a new sedan called the 300. It was developed by Virgil Exner, a new stylist hired by Chrysler Corporation. Exner’s designs were radical for the time; they were basically simple and void of the excessive chrome that most mid-50s cars had. Chrysler dubbed the new designs their new “Forward Look.” Exner claimed the Forward Look designs was influenced by the tailfins on the P-38 World War II aircraft. They weren’t just for looks. He believed in their aerodynamic effects and fine-tuned their performance in wind tunnels at the University of Michigan.
While the design of the new 300 was striking, what really set it apart was the special 331 cubic inch Hemi engine that Chrysler dropped in them. It was hopped up with a Carter 4 Barrel carburetor, solid lifters, a special cam and a free-flow exhaust. Thanks to Exner, the 300s had some handling features too. First, they had extra firm suspensions which allowed them to corner far better than most other cars on the market. And, unlike other performance cars, it had luxury options such as high-end leather upholstery, their new PowerFlite transmission and an especially well-designed instrumentation panel. Journalists of the day considered the 300 the “ultimate gentleman’s sports sedan”.
According to Lynch Chrysler of Mukwonago, a local Chrysler, Dodge, Jeep, Ram dealer in Mukwonago, WI, the 300s were offered in only a limited number colors and trim and only in two door hardtops or convertibles. They could be ordered with standard transmission in certain years, but production was very low with that option. Still, each year since 1955 saw the engineering and performance of the famous Chrysler 300 improve and sales slowly increased.
And they were fast. Famous race car driver Tim Flock raced a 300 at Daytona in 1955, winning both on the road course and the flying mile events. In 1956 model, now designated the 300B, won both events that year too. And the Chrysler 300s dominated the NASCAR tracks in 1955 and 1956, taking the overall championship both years. The legend of the Chrysler Hemi was becoming firmly established.
The 300 with the Hemi engine was discontinued in 1959. In the 4 years of production, there were just 14,268 hardtops and 2,588 convertibles produced. The reason that the Hemi was discontinued was solely due to cost. Hemi engines had complex valve trains that were expensive to make and build. In their place Chrysler went back to an updated “wedge head” design and they used that design for several decades.