primotipo…

Clarence La Tourette’s superb cutaway drawing of the iconic, important Chev Corvette SS…

Regular readers will know I am a cutaway fan.

My favourite practitioners of the art are Vic Berris, Theo Page, Paolo D’Alessio, Tony Matthews, Bill Bennett, Bruno Betti, Giuseppe Cavara, Yoshihiro Inomoto and Clarence La Tourette- who I assumed was based in France. In fact he was working as a Technical Artist at Lockheed in the US when the newly appointed editor of Sports Cars Illustrated/Car and Driver, John Christy, brought him into the mix together with writers Griff Borgeson and Karl Ludvigsen in 1956. La Tourette drew the magazines cutaway centrespreads in his spare time. And absolutely marvellous they are.

One writes about such well known cars as these Corvettes with trepidation, but La Tourette’s beautiful drawing was too good not to publish. The article is a quickie to support the photographs, it offers Chevy hardcore no new insights but ‘newbees’ to this car like me an introduction.

GM famously rushed the first Corvette to market, it sold well in 1953 despite poor quality, its wheezy ‘Blue Flame’ in-line six cylinder engine and very limited availability. Only 700 were sold in 1954 and Chevy die-hards have it that only a 1955 memo from Zora Arkus-Duntov to Chev Chief Engineer Ed Cole, guaranteeing the commercial success of the car, saved it from the production axe.

Arkus-Duntov was hired by Cole in Autumn 1953 after he saw and was excited by Harley Earl’s ’53 Corvette Prototype at the 1953 Motorama in New York. At the time the Belgian born American former racer was running a family business selling souped up Flathead Ford V8’s. A-D famously improved the cylinder head of the 265 cid small-block Chev V8- the first in a phenomenally successful run of cast iron, push-rod, relatively light and powerful road and race engines.

A-D presented a paper to the Society of Automotive Engineers extolling the virtues of a sportscar marketing approach in which such cars were ‘endowed with a racing halo provided by a few specialist machines of the same make’.

Putting into practice what he preached, Zora took a pre-production updated ’56 model to Pikes Peak early that year and won his class. Cole, by then GM of Chevrolet, approved a production speed record attempt at Daytona and the car set a speed of 150.583 mph in a car sans windscreen and with the ‘Duntov-cam’.

Chevrolet entered a Corvette fitted with an experimental 307 cid V8 at Sebring in 1956, the John Fitch/Walt Hansgen driven car finished 9^th in the race won by the Fangio/Castellotti Ferrari 860 Monza.

Cole spoke to A-D about fitting a Chev engine to a Jaguar XKD Bill Mitchell bought but Zora argued for a racing version of the Corvette to be built instead and to be entered at Sebring in 1957.

Two cars, code named Project XP-64, were built by the Chevrolet Engineering Centre in the six months available- a ‘mule’ which used a fibreglass body over a multitubular spaceframe chassis and a race car which was to have hand-formed magnesium panels.

The engine was the latest iteration of the small-block, a 283 cid V8 fitted with fuel injection giving circa 307 bhp- to which was bolted a four-speed gearbox. Front suspension comprised upper and lower wishbones (A-arms) with coil spring/damper units. The rear used a de Dion tube, Halibrand quick-change differential, coil spring/dampers and inboard aluminium finned drum brakes- drum brakes were outboard at the front.

The mule weighed 1850 pounds, the magnesium body would save 150 pounds but time was not on the teams side so all of the testing was done with the mule. No less than Juan Manuel-Fangio was engaged to drive the car but he was released from the deal when it became apparent it would not be ready- contracted to Maserati in his final full season of racing he won the event in a Maser 450S co-driven by Jean Behra.

 

Nonetheless Fangio tested the car and lapped quicker than his previous years record lap-time. When the racer arrived all the ‘sorted bits’ were transferred from the mule to it, the car driven by the vastly experienced Piero Taruffi and John Fitch. It retired after only 23 laps with ‘electrical gremlins, bad brakes and terminal rear end problems’, sad really as the car dominated the early laps and achieved a top speed of 183 mph.

John Fitch said ‘That car had so much potential, but we never had time to make it race ready. We didn’t get the car to the track until the very last minute and so we transferred the parts that worked, and everything we refined on the mule to the racing car when it arrived. The brakes were absolutely terrible and they never got that resolved. For some reason Zora Duntov made the decision not to use disc brakes on the car and it was a bad one. We had absolutely no time to sort that car out. If we had we might have made a real impact on that race’.

None of the problems were any less than could have been expected of a car at the commencement of its development curve but aspirations for Le Mans and other blue-riband events were scuttled with the American Automobile Manufacturers Association ban an manufacturer supported motor racing off the back of the 1955 Le Mans disaster.

Both cars survive of course, the Mule was sold to Bill Mitchell, then GM Vice President of Styling for a dollar who turned it into the Stingray Racer…

Etcetera: Sweet coupe, A-D up…

Bibliography/Credits…

Clarence La Tourette, chevyhardcore.com, myautoworld.com, General Motors, Gene Bussian

Tailpiece: Zora looks rather happy with his team’s creation, as well he should. A wonderful mighta-been…

Finito…