The world’s biggest business corporation, General Motors, is continuing production of its Chevrolet Corvette coupe’s and convertibles for the 23rd consecutive year, and the two-seater is currently enjoying more success than ever before.
Conceived in 1951 as a cheap fun car, the first Corvette was drawn up by Robert McLean within a design team headed by Harley Earl. The first Corvettes were actually manufactured in June 1953, with full mass-production commencing in December of that year. It was not an overnight success and GM seriously thought of withdrawing from the project when there were over 1,000 unsold Corvettes at the end of 1954.
However, as has been recently proven in America, you can often fight your way out of a sales crisis by going the opposite way to the rest; of the World: install a bigger engine and scale the car’s whole image up-market. For 1955 Chevrolet were able to offer the then new 265 Cu. in. (4.3litre) V8 as an option. That move laid the pattern for the future, but 1955 sales were pretty disastrous at just over 1,600 units! However the VA became more powerful, and standard equipment for 1956, together with much improved handling and three-speed manual gearbox to replace the previously mandatory two-speed automatic! The result was that sales just exceeded 4,000 units that year and, as the car grew progressively more powerful, and more sophisticated, sales went on climbing until double figures were reached in 1960 (over 11,000 Corvettes sold), with over 20,000 such cars sold soon afterwards in 1963. Sales stayed in the 20,000 per year range right up until 1972, then right through the fuel crisis they have just gone an accelerating ever upward! Quite why this should be, apart from the fact that the car seems more eye-catching than ever is unexplained, though I believe • Cadillac did very well through the American recession as well A tremendous 45,961 Corvette sales were racked up in their record 1975 year, and things are apparently going just as well, if not better, this year.
There’s not a lot of common ground between a 454 Cu. in. (7.4-litre) Corvette and yesterday’s 3.8-litre straight sixes (developed from a 1940s truck motor), except the model name and the use of glassfibre as the body material. The car reflects a fascinating amalgam of American and European thinking, whatever period you choose in its life, and has a character that is a mile away from all the faceless standard tinware that forms the bulk of Detroit profits.
That the Corvette exists at all is something of a puzzle. Why should the world’s largest motor manufacturer take its mass-production conscious Chevrolet division into battle with others, contesting a market that was absolutely miniscule by their standards? The answer seems to have been the emergence of dynamic characters to hack the Corvette through its birth, the idea attracting the kind of opportunity for executives within the corporation to really stand out from their rivals by recommending steps like the racing and record programme, and the ever-escalating performance, which must have made some of more Nader-conscious management wince with embarrassment on some occasions. Plain human enthusiasm is not the prerogative of the backyard special builder.
One man’s name is always quoted in connection with the Corvette, Belgian-born Zora Arkus Duntov, who has worked for a few people in Europe as well, including the late Sydney Allard. Duntov joined Chevrolet’s Research and Development Division in 1953 and he and the Corvette have really grown inseparably together for aside from his engineering contribution, Duntov has raced them (he also captured a NASCAR observed 150.586 m.p.h. record for one mile at Daytona Beach in 1955) and has always seemed to be the source quoted at each new model year of the Corvette.
During two decades of production, the Corvette has been through three primary bodystyles and a host of mechanical changes, but that is almost as nothing to the astonishing amount of background work—particularly on the competition side—that has been usually initiated by Duntov. The car has kept a contemporary look through adaptation of show car specials, the current style tracing back to 1965’s Mako II display Corvette.
In the beginning the car had a simple box section frame clothed with the original body style that, facelifted with such items as twin headlamps and many more minor styling alterations, lasted until the advent of the Stingray coupe in 1963. From that point onward there was production of both the traditional open model and the new coupe: in 1963 they sold equal quantities, by 1972, coupes accounted for three-quarters of all sales. The final major (and I must stress major, the American penchant for changing something every year often resulted in extra width/length at the change of a model year) was the adoption of the body you see in our colour pictures. This style came in 1968 and was modified in 1973 with the installation of a deformable nose and rear-end, the latter appearing in 1974.
The car in the pictures was manufactured in 1971 and is representative of the kind of Corvettes which were sold in such limited numbers in this country in that it has all the extras-7.4-litre engine (not available in the Corvette since 1974), air conditioning, automatic transmission, power steering, electric windows and so on . . . more of that later.
Mechanically the changes have been a lot more evident. In the beginning a straight six-cylinder, with triple Carter carburetters, developed 150 b.h.p. at 4,200 r.p.m., backed by 223 lb./ft. torque. The glassfibrebodied sixes weighed 2,850 lb., whereas today the weight is closer to 3,700 lb. By our standards the six offered reasonable acceleration, with 0-60 m.p.h. accomplished in 11 seconds or so, coupled to a maximum of a little more than 106 m.p.h. Unfortunately Ford were getting into their stride with a V8 Thunderbird in 1954, so it was inevitable that the Corvette soon left behind its lightweight, cheap and cheerful pretensions and swept off along the V8 road to success, fighting Ford along the way.
Up to 1973 gross horsepower figures had only been quoted. Cars up to that year contain the most powerful American engines of all, the emission control regulations subsequently detuning the Corvette in just the same way as all its rivals. A 1976 Corvette was timed at only 124 1/2 m.p.h. by Car and Driver magazine recently, its 5.7-litre V8 strangled to 210 horsepower. Today the car costs just over $10,000 with all the extras installed, comparing with slightly under $3,500 when it was announced 23 years ago.
In fact the most powerful engine listed for the Corvette was the 1970 version of the 7.4-litre V8 installed in the car used for our pictures. That delivered a gross 465 b.h.p. on a 12.25 c.r., but it was never sold to the public as GM hacked off from such high outputs in an increasing atmosphere of safety and pollution concern. However, gross outputs of over 400 b.h.p. were listed from 1965, with a 6.4-litre V8.
Apart from competition proven hardware to improve the Corvette’s engine performance, there was one major production item that played a big part in the development of the Corvette’s “image”, and that was the adoption of fuel injection in 1957. Made by the American Rochester carburetter company, the injection was refined and produced at lower cost year by year, but was finally dropped for the 1966 model year as the big engine performance phase became a cheaper way of finding the high performance needed to sell cars at that time. When injection was introduced on a 4.6-litre motor there was a big fanfare based on a gross output of 283 b.h.p. from the same number of cubic inches. By the end of 1965 the fuel-injection engines had yielded a claim of 375 b.h.p. from 5.3-litres, which remains the highest output recorded in production for the family of Chevrolet V8s between 4.3and 5.7-litres, options offered for the Corvette was the 1969 ZL-1, the aluminium V8 that formed the base for McLaren’s all-conquering Can-Am power units. Fitted with a single, four-choke, Holley carburetter these engines were said to produce a boggling 585 b.h.p., enough to produce 12-second quarter-mile times, according to contemporary reports.
There were other pretty significant landmarks too, especially by American car industry standards, the Corvette often serving as a useful tool to introduce “new” ideas in practice to a largely sceptical public. The early two-speed automatic went in favour of a three-speed manual, but automatic gear-selection has always been available. A four-speed manual option followed in 1957, though automatics still account for a good percentage of sales. “Our” car had a three-speed GM automatic which offered outstanding over-ride and kickdown selection, despite the presence of 36,000 hard miles on the odometer.
The leaf spring rear suspension went in 1963, the new Stingray style offering an independent rear-end around transverse lower leaf springs. This system, like the rest of the Corvette, tried to use as many production parts as possible, and it’s said that it ended up being cheaper to make than the old live axle: drive shafts acted as top links.
For the 1965 season Chevrolet finally had persuaded their Delco division to come up with acceptable disc brakes after several earlier attempts had been disappointing. The calipers were patterned after the British Girling-type, working on big ventilated discs: when they did get around to doing the job the GM people certainly did it thoroughly, and we were most impressed with the basically similar system of the Corvette we borrowed, the pedal action being progressive in the manner of the best Europe has to offer.
I certainly looked forward to trying the Corvette myself, the opportunity coming up at very short notice owing to a last- minute change in our contents this month. the Chequered Flag on Chiswick’s High Road generously lent us their 1971 454 model, which had actually been sold, so they had everything to lose by such a move, should it’s 365 (gross) b.h.p. prove too much to cope with on such wide wheels.
Quite honestly it was a unique experience. The coupe model features a split roof that can literally be detached in seconds. With the top panel removed and the deep “thumpity-thump” of the exhausts to accompany a ride on a hot May afternoon, the corvette certainly exudes character. A remark that’s even more true when you look forward as the wings thrust curvaceously up either side of an equally symbolic power bulge in the middle of the bonnet. I have certainly never seen a view like it (on a motor car), and the machine certainly couldnt be described as easy to park, the large threequarter blind spots and great humpy wings managing to obscure part of the rear view.
To drive effortlessly along the road this car demands the minimum of effort. It is worth worth pointing out that Chevrolet offer options that completely alter the car’s character from 200 m.p.h racing parts to soft pavement cruiser (poser?). the power steering and automatic transmission allow one to drift along with only that potent engine rumble to remind you that this is a performance car of the front rank. Contemporary 1971 tests quote electronically timed 0-60 m.p.h. runs at 5.7. Seconds (and this car was quite soft by prevailing standards, with an auto!) rushing on to cover both the quarter-mile and 100 m.p.h. within 14.2 seconds. “Our” car had been standing idle for a bit, but by the end of a 10 m.p.g. afternoon, the cobwebs seemed to have all emerged and the Corvette was leaping through spaces in the sort of swift rush that the riders of large capacity motorcycles become familiar with.
Much of that speed comes from a massive 460 lb. ft. of torque, but the driver is cosseted in comfortable seats that offer rather more side support than one has any right to expect from such flat shapes. Instrumentation comprised a large 160 m.p.h. speedometer (this model was timed at 141 m.p.h.) an inoperative tachometer, redlined at 5,500 r.p.m., and five smaller centre console dials to tell you the time, oil pressure (35 to 60 lb.), water temperature, battery output, and whether there was any petrol left.
The ride and handling of this particular car were not impressive, and this was no surprise as non-standard wide wheels led to a lot of straight-line darting around on B roads (Chevrolet’s 8-inch rims should be a lot better), the ride has usually been adversely commented on by Europeans, or European-orientated journalists. By contrast the roadholding was excellent, not surprising as Corvette’s distribution of weight has bene close to 50/50 front to rear since the beginning. The light power-steering tells you enough to correct quickly, if need be, and that is rarely for a power slide with an automatic on oversize wheels.
Inspired by our experiences with this car –which was sold for a very reasonable price that took account of some interior rectification that was needed –I thought we ought to explore the possibilities of buying a Corvette in Britain. Of course, you have to talk to Lendrun and Hartnum at 122 King St., Hammersmith, London W6. The sales people there sounded pretty teed-off with the whole idea: “We’re waiting for the 1976 models, it hasn’t been E-marked yet, but it’ll cost £6,800, fully equipped”. I wondered how many they had sold, and it seemed to be a handful, while the gentleman also informed me that you could only get the 350 (5.7-litre) in this country now, and they had never had any 1975 models in at all!
Otherwise there’s the secondhand market, but with this and the idea of bringing in Corvetts directly from America, beware the E-mark scheme; it’s illegal to use a car without one in Britain, if it was manufactured after 1973. – J.W.