Bowtie Breakthroughs: ’59 Corvette Stingray Prototype

It may have been that, when Harley Earl retired from General Motors in 1958, Bill Mitchell breathed an enormous sigh of relief. Surely, it was not that Mitchell wished him gone, though, as he had worked comfortably under the legendary stylist since December of 1935.

Mitchell’s connection with automobile racing was well established before he started at GM. Mitchell’s father had been a car dealer and his son, at an early age, was exposed to many of the classics of the time. Following high school, young Bill attended Pittsburgh’s Carnegie Institute of Technology and, later, the Art Students League in New York City.

Mitchell landed a job at the Barron Collier advertising agency, eventually running into the founder’s sons, Miles, Sam and Barron, Jr. Sportsmen all, they reserved their greatest enthusiasm for motor sports with Miles and Sam founding the Automobile Racing Club of America in the early 1930s. Mitchell’s graphic talents soon led to him becoming the official illustrator for ARCA. His work, often posted in the ARCA club house, drew the attention of a friend of Harley Earl’s, who suggested that Mitchell send him a portfolio.

The 1959 Stingray racer displayed none of the Harley Earl influence, instead trading on sharply defined character lines and modern looks.

Earl, who was always on the lookout for talented people to join his design section, brought Mitchell into the group of 90 people at the time. Mitchell’s rise was little short of meteoric from that point. At age 26, he was appointed chief designer for the Cadillac Studio, where he designed the first “personal luxury” car – a smaller, but trend-setting Cadillac whose styling themes would echo throughout the company for a decade.

Using the chassis from a previous Corvette race car, Mitchell's group quietly built an up to date version that would be used in SCCA racing.

Mitchell took a four year sabbatical, as a lieutenant in the Air Arm of the U.S. Navy, before returning to direct the Cadillac studios once again. His continuing design leadership made Cadillac the style leader of the world and enhanced its position of esteem in the marketplace. On May 1, 1954, Bill Mitchell was named director of styling and continued in that position until being appointed vice president of Styling on Earl’s retirement.

Mitchell had maintained some connection with racing throughout most of his GM career. In fact, in 1956, he acquired a D-type Jaguar with the intention of having one of the new fuel injected, small block V8’s installed to take on foreign competition at Sebring and later Le Mans.

Ed Cole asked Corvette chief engineer, Zora Arkus-Duntov, to look after the job, but Duntov felt that a purpose-built Corvette would have a far better chance of winning the 1957 Sebring race. Cole approved the project and the tube-framed, magnesium-skinned Corvette SS project was underway.

The time and technology hurdles for the project were daunting. There were but six months to complete and shake down the car. Duntov built a number of chassis for the project and the first test car wore a fiberglass body. The SS would use the latest iteration of the Chevrolet small block V8, fuel injected and delivering 307hp. The front suspension consisted of unequal length A-arms with coil-over springs and shock absorbers. The back end was made up with a de Dion axle, Halibrand quick-change differential and inboard, aluminum-finned drum brakes. Even with its composite body, the “Mule” weighed in at just 1,850 pounds.

Incorporating both components and lessons learned from past excursions to Sebring, the first Stingray used a low-cut windshield and aerodynamic pod behind the driver's head.

In the end, the time line was simply too aggressive. Most of the shakedown at Sebring was done using the Mule and bedded-in components moved to the race car when it arrived at the track. The Corvette SS entered in the race completed 23 laps and was then retired with “electrical gremlins, bad brakes, and finally, terminal rear end problems.” During those first laps, however, it dominated the field and recorded a top speed of 183 mph.

Shortly after, the 1957 AMA Ban on manufacturer-supported racing ended all development and racing activities by American auto manufacturers. This action resulted from a horrific accident two years prior at Le Mans, when a disastrous crash killed 83 spectators and injured another 120 people.

Still looking to build a car that would dominate endurance racing in Europe, Mitchell had started a project called XP-87. Due to the AMA ban, Mitchell was told to remove any association with the Chevrolet and Corvette names. Mitchell’s project was renamed “Stingray” and, according to reports, he was able to purchase one of Duntov’s Corvette SS chassis for a dollar.

Many of the design cues for the second generation Corvette were taken directly from Mitchell's Stingray project.

On his own time and using his own money, Mitchell contracted GM stylist, Larry Shinoda, to help in the development of the car’s design. Where Earl had favored rounded lines, chrome accents and substantial presence, Mitchell preferred sharp, defining lines and a less weighty appearance. Mitchell held an informal competition within his group for the new body. Junior designers Peter Brock and Chuck Pohlman won out and worked with Mitchell and Shinoda to build a clay model. All of this was going on within GM at the time and executives were blissfully unaware – or chose to be so.

When the fiberglass body was complete and fitted to the Duntov chassis, the result was simply breathtaking. Many of the lessons learned from previous Sebring forays were incorporated in the race car. Duntov had fitted a newer, fuel injected 283 engine that produced 315 horsepower. This would help to keep the car competitive, despite its increase in dry weight to around 2,200 pounds.

In 1967, the Stingray was repainted red and driven by Elvis Presley in the movie "Clambake."

Mitchell engaged veteran Corvette racer, Dr. Dick Thompson, to pilot the car in SCCA racing. In both 1959 and 1960, the pair brought home SCCA C-Class championships, despite significant competition from the likes of Jaguar, Maserati, and Scarab. After this, Mitchell retired the Stingray from racing, adding a full windshield and a passenger seat. It became one of his personal cars and was later used as a show or concept car.

While still an early science, aerodynamics would continue to grow in importance in the development of future GM cars.Work had started in mid-1959 on the development of the next generation Corvette, due for the 1963 model year. GM Styling had designated the project car XP-720 and it leaned heavily on Mitchell’s Stingray design. Shinoda completed a first clay model in October, which was little more than the Stingray with a coupe’s roof on it. Mitchell later told Corvette historian David Chippen, “When it came time to face-lift the Corvette, I took the lines right off that car.”

By early April of 1960, Shinoda completed a second clay model for presentation to GM Management. The new design was approved in short order and the second generation Corvette came into being.

The 1963 ‘split window’ coupe would become one of the most collectible Corvettes in history. Before Mitchell retired from GM in July 1977, he had created more than fifty one-off cars for various purposes, from concept and show cars to custom production cars for his own or his wife’s use.

It can easily be argued that his influence on the design of General Motors’ product over the span of his career is at least as significant as that of Earl’s. Some of the other cars he is most closely credited with are the ’63 Buick Riviera, the ’66 Oldsmobile Toronado, the ’67 Cadillac Eldorado and the second generation ’70 Chevrolet Camaro.

About the author

Don Roy

Don's background includes 14 years in the OEM and Tier2 domestic auto industry, as well as three years as Technical Editor of a muscle car enthusiast print magazine. He is a mechanical engineer by trade and completed his first project car when he was 16 years old - after rebuilding the engine in his bedroom. His hobbies include photography, film making and building the odd robot from time to time.
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