Tom Hoover was a legend within the Chrysler Motor Corporation. He was the creator of the famed 426 Hemi, 413 Max wedge, and had a hand in creating the Slant six hyper pak, the sonoramic commando engine, and many high performance engine principles. His 426 hemi is the base for nearly all top fuel dragsters since its conception.
He was born on November 28, 1929, in Huntingdon Pennsylvania. Before pioneering the Chrysler race division, he studied at Juniata College . He soon joined the Pennsylvania national guard and was inducted into the U.S. army to be deployed to aid the Korean conflict. During his stint In the army that lasted until April 1952, he achieved the rank of sergeant and received a Korean service medal with three bronze campaign stars and was honorably discharged.[1] With his feet back on U.S. soil, he attained an undergraduate's degree in physics and a master's degree in engineering at Penn State University . In 1955, he found employment at Chrysler Corporation and subsequently enrolled in Chrysler Institute of Engineering to obtain his masters in automotive engineering.
High and Mighty
He discovered a love for racing after going to a few with his colleagues. Him and eight other Chrysler engineers started putting together an experimental race car that would soon be known by all as “High and Mighty .” This prototype was a 1949 Plymouth Business Coupe equipped with a 354 hemi engine. The intake and exhaust systems were the most experimental parts of the car. The intake manifold stuck out the hood and over the roof of the car, measuring 48 inches overall. The manifold was a scrap left over from an engine performance study which measured the wave tuning effects of specific intake manifold runner lengths; ranging from the average 10 inches to the extreme 48 inches. It also sported trumpet-like horns for each cylinder instead of a regular exhaust manifold or header. Tom got the idea from a theory in Norton Motorcycle Technical Paper. The concept would not be used outside of racing engines for more than a decade afterward. It was said to be the loudest vehicle out of all of the competitors because of its unique exhaust.[2]
The High and Mighty experiment was a great success that won 1959 NHRA (National Hot Rod Association) Nationals at Detroit Dragway and landed Tom a job as an engineer for Chrysler's performance division. They took inspiration from the “tunnel ram” that High and Mighty had and created the ram induction big block for the 1960 and 1961 Chrysler, Dodge, and Plymouth vehicles.
Ram Induction
The ram induction engine was unique only in its intake manifold. It was the first true cross-ram production engine that ran two split manifolds that measured thirty inches and had dual four barrel carburetors. The intake was plumbed with hot water from the engine to encourage fuel atomization because the carburetors sat just above the valve covers, leading to issues with too much heat dissipation. These engines were especially torquey at low rpm and were said to be amazing highway cruisers, but they were not built for performance.
Hyper-pak slant six
After his success with the ram induction, Tom helped with Chrysler's compact division of racing. He used his prior knowledge to create the hyper-pak slant six that ran a long intake manifold, much like ram induction, that took up the majority of the engine bay. It sported a single four barrel carburetor and had a more aggressive camshaft than the original design. With these modifications, they managed to squeeze in an extra fifty horsepower for a total of 200. “Plymouth Valiant that was so successful in its first race outing in the compact class at Daytona in 1960, powering the first seven finishers, that NASCAR's inaugural compact race was also its last”.[3]
413 and 426 max wedge
His success with the Hyper-Pak landed him in the role of head engineer at Chrysler race division, where he created the 413 and 426 Max Wedge engines. The Max Wedge was a Chrysler big block (B) engine that had a raised deck height in order to increase the stroke. It also ran larger cylinder heads, a much healthier camshaft, and a box style cross ram intake manifold. In 1962, the 413 max wedge was introduced and it was competitive with the other companies but did not make extreme waves in the races. By 1963, the displacement was increased to 426 cubic inches, but otherwise remained as it was.
426 Hemi
With the lack-luster performance of the wedge engines Tom decided to redesign the engine in its entirety. He scrapped the wedge cylinder head design in favor of the tried and true Hemi heads. With this modification came slight changes to the block and camshaft with a significant increase in power as well as an increase in overall size, thus reviving the Chrysler Hemi Engine. This increased size and power gave it the nickname the “elephant motor.” With this “elephant,” Chrysler won the 1964 Indy 500 by such a huge margin that the NHRA changed their rulebook to disallow non-production (unorderable) vehicles. Because of this, Chrysler boycotted the race until 1966, when they came out with a street version of the 426 hemi that met the new race requirements.
The NHRA changed their rules so that in order to race, the company needed to have their race car able to be ordered from the factory and have at least five hundred vehicles manufactured. These changes caused Chrysler to have to water down the hemi to be viable for street use. The street hemi had a smaller camshaft, a smaller exhaust manifold, an inline dual carburetor setup rather than the previous cross ram, and a 10.25:1 compression ratio instead of 12.5:1. The street hemi was an immediate hit with the public and in 1966, Chrysler sold 2,729 hemi cars. The hemi was held to its high standard, despite being watered down, winning 27 races in 1967 alone.[4]
Tom Hoover is a legend that paved the way for hundreds of racing records. He created several notable engines and in the process discovered many modern engine principles. He was a landmark in the automotive world, inspiring awe in those around him.
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