Sonoma Historic Motorsports Festival
Saturday June 2, 2018
Chevrolet’s Corvette has been with us for over five-and-a-half decades. Along the way a multitude of “concept” versions have been produced. Concept is the name given to cars that are experimental, either in design, engineering, and occasionally both. The latter was the category into which several Corvette concepts fell in the 1950s, and 1960s. Most ended up as scrap, some were redone, and many of them were never seen or heard of again after being displayed at Auto Shows. Some, however, were the basis for new models, new features, or the foundation for an entire generation. In fact, the very first Corvette, introduced at the 1953 Motorama in New York City, was itself a concept car.
The creation of the Corvette was the pet project of GM Styling Chief, Harley Earl. His idea first led to two show cars and a “mule” for testing. One of the show cars debuted at the Waldorf-Astoria, the starting point of the 1953 General Motors Motorama tour. This fiberglass prototype, EX-52, Shop Order (S.O.) 1737, generated enough enthusiasm from the public to push production ahead by several months, resulting in the use of Fiberglas for the bodies to hasten production.
Prototype Corvettes differed notably from the production versions – they were heavier, constructed with thicker Fiberglas, and formed as a one piece body. For production, the upper front and lower front, upper rear and lower rear body sections were joined and the rocker panels were glued and riveted to the assembled body. The resulting seam was hidden with bright trim. Hydraulically operated hood and trunk lids were installed for display purposes on at least the first prototype; these panels opened and closed as the show car revolved on its turntable.
Four more prototypes were ordered beyond EX-52, but two of these were soon cancelled. The “Waldorf” car was assembled by GM Styling and Chevrolet Engineering, while the other two bodies were supplied by Fisher Body and assembled by the Chevrolet Experimental Department. The second show car was displayed in the U.S. and Canada. The two show prototypes were nearly identical, but the second car lacked the cowl scoops and Continental-type door pushbuttons of the first car. Other minor details varied under the hood as well as in the interior. The other prototype was used strictly for a variety of tests and was not show quality.
According to GM memos, the original EX-52 prototype was dismantled; its body was destroyed during flammability testing and its frame was altered for use on another show car, the 1954 Chevrolet Nomad. Presumably the other prototypes were scrapped.
For a while, GM was considering a line of Corvettes, thus two Corvette-based prototypes – the Nomad (S.O. 1954) and the Corvair (S.O. 2071) – were crafted along with a mildly modified Corvette wearing a prototype detachable hardtop (S.O. 2000) for the 1954 GM Motorama.
Carl Renner was put in charge of styling the two-door Nomad station wagon. Its side trim was similar to the 1953 Corvette prototypes, but extended to the doors. Conventional door handles rather than push-buttons were employed and the exhausts exited through a port on each quarter panel. Since the overall height (54 inches) of the Nomad was low, the top of the roof was visible. Harley Earl saw a need to give this area some sort of visual interest; ultimately, a series of grooves running side-to-side on the roof, aft of the B-pillars, was chosen. Overall length and width measured 191 and 71 inches, respectively. Wheelbase spanned 115 inches – 13 inches more than a Corvette.
Upholstery for the bench seating was in a combination of blue, white, and silver leather and fabric. The rear seat could be folded forward to sit flush with the cargo floor. Overhead, a series of chrome bows decorated the white headliner. Embossed stainless steel covered the cargo floor. The lower rear panel under the tailgate opened downward allowing access to the spare tire.
Rumors persist that a ’54 Nomad still exists, but an equally compelling account of one being scrapped is just as persistent; two examples being built would nicely explain both stories.
The distinctive 51-inch high Corvair featured a panoramic windshield, a fastback roof that swept back to a jet exhaust-type opening, a trio of rectangular inlets on the fenders for interior ventilation, and twin bulges with chromed slotted vents on the hood to let the heat escape the engine compartment. Exhaust vents for the interior air were mounted on the swept C-pillars and controlled with manual buttons inside the car. The show car was said to be powered with a stock Corvette driveline.
The Corvair was seen in two colors – a deep red and a pale blue-green. Changing the color of a Motorama car was not especially common, but it did happen. However, in the case of the Corvair, almost certainly two examples were built.
Regardless of the exterior color, the interior was upholstered in light beige leather; the pattern on the seats and the door panels differed from that of a production Corvette. A bulkhead sat directly behind the bucket seats while a filler plate covered the area from the bulkhead all the way back to the bottom of the backlight.
According to two eyewitnesses interviewed by this author for a 2003 story about the GM Motorama cars published in Car Collector magazine, (three part series published in issues Sept. Oct. and Nov. 2003) the car– described by both as a red 1953 to 1955 style Corvette fastback – was seen at Warhoops (salvage yard) sitting atop one or two other cars.
The other special Corvette displayed during that year’s Motorama (starting with the Miami show) tour had a prototype fiberglass top in addition to roll-up windows. (Production Vettes had snap-in panels.) A taller windshield and frame assembly was installed on a 1953 Corvette painted pale yellow and its interior was outfitted with non-production waffle pattern upholstery, as well as a small glove box on the right kick panel. Door panels differed, too. Similarly patterned upholstery and door panels along with the hardtop were adopted for 1956.
Two of the hardtop cars were built. The second of these was displayed at Canadian shows and perhaps elsewhere. It was taken off the assembly line and given nearly the same modifications as performed on the first car, but its color scheme was a gold-tinted maroon with a maroon interior. According to an article written by Wayne Ellwood and Noland Adams published in the Summer 1999 issue of SHARK Quarterly magazine, it was sold by GM in August 1957 to an employee of the Truck Sales Department in Oshawa, Ontario. This car still exists and is now owned by a resident of Vancouver, BC.
No Corvette show cars were created for 1955. Production versions were displayed, though the one-year old 1954 show cars continued to be exhibited at dealerships and auto shows. One of the reasons was that the 1954 models had not sold well and hundreds were still sitting on dealer lots when the 1955 models were introduced. The Corvette’s future was even in question until plans finally took shape for an all-new 1956 models.
The 1956 Corvette Impala (XP-101, S.O. 2487) was the embodiment of what a Corvette as a five-passenger sports car could have been. This fiberglass show car designed by Bob Cadaret (who worked on the new 1956 Corvette’s design) and Carl Renner had a 225 horsepower Super Turbo-Fire V8 engine, “Powerglide” transmission, power windows, integral bumper and grille, tinted panoramic wraparound windshield that curved up into the pale blue-tinted brushed stainless steel roof, wraparound rear windshield, beltline dip near the reverse slant C-pillars, and chrome-plated wire wheels with knock-off hubs. The car’s dual exhaust pipes passed through the driveshaft tunnel into a transverse-mounted muffler and the dual outlets from the muffler projected through the rear body panel.
Exterior dimensions of the Corvette Impala were 74.4 inches wide, 53.7 inches high, and 202 inches in length; its wheelbase spanned 116.5 inches and road clearance measured six inches.
The show car’s color for a while was similar – if not identical – to Aegean Turquoise Metallic, a color which was offered for the 1958 model Chevrolets. A photo of the car at the Chicago Auto Show in 1957 clearly shows the color was changed to a bright blue.
A padded bar of air foil shape emerged from the steering column and angled upward to flatten into a horizontal plane that spanned the entire width of the interior; it contained the various controls and teardrop shaped heater outlets. The center section of the padded cowl contained a recessed radio and drum clock. A speed warning system, consisting of ten circular windows across the instrument panel, were said to light up progressively in more intense shades of red as higher road speeds were attained. Upholstery was a combination of silver-blue vinyl and crosshatch pattern nylon. The front seat was equipped with a fold-down center armrest with a map case, while the rear seat featured a fixed central armrest with power window switches, courtesy light, and ash tray. Seat belts and a sloping package tray were included as safety features.
Several styling cues of the Corvette Impala such as the reverse slant C-pillars were applied to the Impala introduced as part of the Bel Air series for the 1958 model year. Other features such as the Corvette-inspired grille were considered, but eventually rejected for production.
Reportedly this forerunner of the production Impala was scrapped.
Back in 1958, Harley Earl’s protégé and successor, Bill Mitchell, designed a running concept car called the XP 700. Mitchell had just taken over from Earl as Chief of GM Styling. The XP 700 Dream Car ultimately led to the design of the 1961 and 1962 Corvette models. The dual headlights and fender treatment, rocker panel trim and new Sting Ray style rear end, all evolved from this car, so on occasion dreams do come true.
While Corvette enthusiasts were taking in the sporty lines of the new 1961 models, Mitchell and the design staff were building the Mako Shark, which in turn influenced the styling of the all-new 1963 Corvette. In 1965, the Mako Shark II set the styling pace for the 1968 model line. The aggressive look of the fourth generation Corvette was there in the Shark’s muscular profile and bold front end design. One feature that never went past the concept stage was the car’s unique fade-away paint scheme which duplicated the body coloring of a shark! There is one rumored tale that Mitchell had a shark mounted on the wall of his office and that this was the fading color scheme he wanted for the Mako Shark. The design team, after failing to get the exact match, took the shark off the wall and painted it to match the car! Mitchell never said anything.
More often, Corvette concept cars did not lead to the design of a new model. If it had, the Astro I, shown in 1967, would have put GM light years ahead of the competition. The Astro I featured Chevrolet’s flowback roof design. The car had an electric swing-back roof, instead of conventional doors, and a rear section combined with power elevator seats that allowed the driver and passenger to step right into the car and sit at armchair height. At the push of a button, the occupants were lowered to a semi-reclining position beneath the roof, which closed down to a height of only 35.5 inches. The Astro I was powered by an air-cooled, single overhead camshaft, six-cylinder engine. It was perhaps a bit too advanced for the 1960s but when you look at photos of the prototype today, a number of styling cues that appeared in later years, particularly on European sports cars are evident.
When the Corvette began to generate decent sales figures (due in large part to its getting a sporty, fuel-injected V8), the car’s performance potential began to be explored more thoroughly, especially by Zora Arkus-Duntov. Bill Mitchell and Duntov supervised the design of some mid-engine prototypes for evaluation.
The 1964 CERV II was the first mid-engine car to feature full-time, four-wheel drive. It was followed four years later by the XP-880, ultimately dubbed Astro II. The debut of the Astro II at the 1968 New York Auto Show fueled rumors that a mid-engine Corvette was not far away and it countered the announcement by Ford Motor Company of its intention to sell the mid-engine, Italian-built DeTomaso Pantera. A GM press release about the car said it was “a practical, personal sports car designed to carry two passengers and their luggage comfortably and rapidly.” General Motors’ official press release did its part to start the rumors of a mid-engine Corvette in the future when the final paragraph stated, “Astro II takes a big step in translating the excitement of its brilliantly colored predecessor [Astro I] into possible production reality…”
According to Chuck Jordan, who began working as a stylist for GM in 1949 and later became GM’s fourth design vice president, the Astro II was “somewhat cobbled together” but its appearance did reflect “the design philosophy at the time.” The nose and the taillights of the Astro II XP-880 had a strong resemblance to the 1968 Corvette, which represented the first year of production of the so-called Shark design. The fiberglass body of the Astro II was mounted on a backbone type frame and a Corvette L-36 427 occupied the mid portion. A Powerglide two-speed automatic and Pontiac Tempest trans-axle got the 427’s horsepower to the rear wheels. An aluminum radiator cooled by an electric fan was mounted in the aft end of the car.
The Astro II was followed by the XP-882, which represented “a more serious try” at a mid-engine Corvette, said Chuck Jordan. More than almost any other advanced concept car built during the late 1960s, Astro II came closest to production quality appearance and at one time was thought to be the next Corvette. Ultimately, it proved to be just one of several ideas, none of which ever saw the light of day.
Chevrolet was still thinking about a mid-engine sports car when it proposed the 4-Rotor in the early 1970s. This was yet another possible replacement for the fourth generation model. It incorporated a totally new body design, Mercedes-Benz-style 300 SL Gullwing doors, and the innovative Chevrolet-Wankle rotary engine mounted amidships.
The engine boasted a displacement of 585 cubic inches with an output of 350 horsepower at 7000rpm. When GM’s rotary engine development program ended, the car was fitted with a V8 and renamed the Aerovette.
Cars like the Astro II and 4-Rotor could have changed the entire course of Corvette styling and engineering had their designs been adopted. In general, such wide sweeping changes seldom occur. Change, like ageing, is usually gradual. Exciting and seemingly production ready concept cars like the 1990 CERV III may have pointed the way to the future, but it was not an absolute, just one possible future. That’s why they’re called concepts.
by Dennis Adler and David W. Temple
(Photos and colorized images from the author’s collections)
© Car Collector magazine, LLC.
(Click for more Car Collector Magazine articles)
Originally appeared in the August 2009 issue
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