Chrysler's Early Hemi
Very few innovations in automotive technology have had as great an impact as the advent of the Chrysler Hemi. Born in the 50's it matured into an extreemly powerful and reliable engine only to die a miserable death. When Chrysler decided to bolster it's performance immage in the 60's it was the venerable Hemi that was once again called upon to take on Nascar's high banked ovals. Proving once again that what wins on Sunday sells on Monday. Chrysler's design proved so efficient that it alone is the reason that for the past 50 years nearly all major top fuel and funny car teams use derivatives of the "Hemi" design.
In the late 40's Chrysler realized that it's current line of flat head 6 and 8 cylinder power plants weren't going to make the grade when matched against the new more powerful V8 designs Cadillac and Oldsmobile were planning to introduce during the 1949 model year. They also knew larger engines capable producing more horsepower would be required to haul around the new heavy weight luxo barges Chrysler currently had on their drawing boards. Seeing they were about to be out paced and out gunned, Chrysler decided to develop an engine capable of leveling the playing field. Quite frankly, what the auto manufacturer needed, to quote Tim Allen was, "MORE POWER."
Chrysler's engineers began to research possible V8 engine designs looking for something that might be capable of producing real horsepower. Eventually the decission was made to go with a conventional V8 similar to those being developed by Ford and GM, however Chrysler's version incorporated unique heads with hemispherical combustion chambers.
Although not necessarily a new idea, this design offered a high degree of efficiency both in breathing capability and in heat dissipation. The valves were placed on opposite sides of the combustion chamber. This allowed very short and nearly unrestricted intake and exhaust ports making the airflow in and out of the cylinder extremely efficient. It also allowed the valves to run cooler because of improved air movement around the valve pockets and more cylinder head area to absorb the heat of combustion. In addition the spark plugs were located in the center of the cylinder. This created a very even flame front increasing combustion efficency. All this meant that Chrysler engines could run higher compression ratios without the fear of detonation thereby creating, you guessed it, More Power.