Model Histories
Terms and Technology
Editorials and Commentary
Contact Us
Admin Login
Support Ate Up With Motor
Search Ate Up With Motor
FTC Disclosure Notice
| Rebel Yell: The Life and Death of the Chevrolet Corvair |
 |
 |
| Written by Aaron Severson |
| Friday, 23 July 2010 00:00 |
|
Page 1 of 5 There is no American automobile more controversial than this one. It's the car that launched the career of Ralph Nader, and it led directly to the passage of the first federal safety legislation. Automotive writer Michael Lamm called it a martyr; others said it should never have been built at all. It was flawed, at least in its original iteration, but it was also one of the most daring cars GM has ever built. THE WRECK OF THE CADETOnce upon a time, Chevrolet, Ford, and Plymouth were known collectively as "The Low-Priced Three." That did not, however, mean their cars were particularly small, at least by European standards. In 1934, for example, a Chevrolet Master Six was 175 inches (4,445 mm) long on a 112-inch (2,845 mm) wheelbase; the contemporary Ford and Plymouth were very similar. The Chevy weighed perhaps 3,200 lb (1,450 kg) at the curb, and was powered by a 207 cu. in. (3.4 L) six, which would have made it a very expensive proposition in England, France, or Italy. Furthermore, it kept getting bigger. Thanks to the pressures of the annual model change and the constant one-upmanship of its key rivals, the 1942 Chevrolets -- the last available before America entered World War 2 -- were more than a foot and a half (527 mm) longer than their 1934 ancestors. With the greater size came greater weight, a somewhat larger engine, and a steady erosion of fuel economy.
Deploring that trend, some Chevrolet engineers had pushed for a smaller compact model as early as the mid-1930s, with very little success. The primary obstacle was profit. Small cars cost almost as much to build as large ones, but larger models could be sold for higher prices. As a result, the division's management and salesmen had little enthusiasm for compact cars. During the war, however, Chevrolet general manager Marvin E. Coyne became concerned about the prospects of a postwar recession, like the one that had followed the Great War. As a potential stopgap, he asked engineer Earle S. MacPherson, head of Chevy's Experimental engineering unit, to devise an inexpensive compact car to supplement the division's full-size models. In early 1945, MacPherson's group started work on a compact "Light Car," subsequently christened "Cadet." The Cadet was a smallish four-door sedan, riding a 108-inch (2,743 mm) wheelbase. Its target curb weight was about 2,400 lb (1,085 kg), and it was powered by a 133 cu. in. (2.2 L) OHV six, making about 65 hp (48 kW). It was modestly sized, frugal, and reasonably nimble, with an early version of what is now known as MacPherson strut suspension. Its target price was just under $1,000, or about 10% cheaper than the least-expensive full-size Chevy. GM announced its intention to build the Cadet in May 1945, but the car's internal support was limited. Corporate chairman Alfred P. Sloan opposed it, as did Chevy chief engineer James Crawford and much of the Chevrolet sales organization. To make matters worse, the Cadet was running well over its cost targets, crushing Coyne's hopes of a sub-$1,000 price tag. When Coyne departed to become vice president of the car and truck group in June 1946, the project began to lose momentum. In September, GM announced that production plans for the Cadet had been suspended. The program was finally canceled in May 1947; in September, MacPherson resigned and went to Ford. Compact projects at Ford and Chrysler met a similar fate, for many of the same reasons. Ford's own Light Car became the 1949 French Ford Vedette, while Chrysler's four-cylinder A-106 was simply canceled. Earle MacPherson's ideas for the Cadet found their way into the English Ford Consul and Zephyr in 1950, but Ford's first postwar U.S. designs were standard-size cars.  The first production car to use MacPherson strut front suspension was the Mk. I Ford Consul, sold from 1950-1956; this is a 1955 fordor sedan. (Photo © 2010 mick / Lumix; used under a Creative Commons Attribution 2.0 Generic license) As the 1950s dawned, only American's smaller independent automakers still seemed interested in compacts. As we have previously seen, Nash unveiled its compact Rambler in April 1950, followed that fall by Kaiser-Frazer's Henry J. Initial sales were promising, and the Rambler and Henry J were soon joined by the Willys Aero and the Hudson Jet. Unfortunately, the U.S. market was not yet prepared to absorb more than about 150,000 compacts a year, not enough to sustain so many competitors. By the 1956 model year, the Rambler and the tiny Nash Metropolitan were the only survivors, and their volume was trivial by Ford or Chevy standards. The swift collapse of the domestic compacts validated the prejudices of Big Three executives, most of whom disdained the very idea of smaller cars. It would take both passion and desperation to convince the big Detroit automakers to enter that market. THE PASSIONS OF ED COLEEdward Nicholas Cole was born in the tiny Michigan farming village of Marne on September 17, 1909. From an early age, he displayed a fascination with machinery, and by the time he was 16, he owned two cars -- wrecks that he bought and rebuilt himself, with money he earned building and repairing radios. Although he studied pre-law at Grand Rapids Junior College, Cole enrolled in the General Motors Institute (GMI, now Kettering University) in 1930, spending half his time in class, the other half working for Cadillac. He secured a permanent position at Cadillac in 1933.
 Cadillac's pioneering OHV V8, introduced for the 1949 model year, was developed by Ed Cole and Cadillac staff engineer Harry F. Barr. Although it was physically smaller and 188 lb (85 kg) lighter than its L-head predecessor, with a smaller displacement, it was more powerful, and had lower specific fuel consumption. Cadillac used variations of this engine through the 1962 model year, and a revamped, second-generation version survived through 1967. In 1941, Cole adapted Cadillac's L-head V8 engine for use in the Army's M-5 Stuart light tank, a project that earned him a promotion to chief industrial designer in 1943. He became chief engineer of Cadillac in 1946, and subsequently led the development of Cadillac's pioneering OHV V8, which, along with the contemporary Oldsmobile Rocket V8, set the standard for almost all American engines of the fifties and sixties. Shortly after the start of the Korean War, Cole was reassigned to run Cadillac's Cleveland Tank Plant, a demanding and politically sensitive position. In June 1952, Chevrolet general manager Tom Keating brought him back to Detroit to become that Chevy's chief engineer, one of GM's most important engineering jobs. Charged with breathing new life into Chevrolet's conservative product line, Cole shepherded the development of the first Corvette, the small-block V8, and the much-beloved '55 Chevy. Cole dramatically increased the size and power of Chevrolet's engineering staff, expanding it from 851 employees to more than 2,900. He also brought in several of his old colleagues from Cadillac, including Kai Hansen and Harry Barr, who had managed the development of the Cadillac OHV V8.  One of the principal products of the Cleveland Tank Plant during Ed Cole's tenure there was the M41 Walker Bulldog Light Tank, powered by a rear-mounted air-cooled flat six -- a supercharged 895 cu. in. (14.7 L) Continental engine. It made 500 gross horsepower (373 kW), giving the 25-ton Walker Bulldog a top road speed of about 45 mph (72 km/h). (Photo © 2007 Stan Shebs; used under a Creative Commons Attribution ShareAlike 3.0 Unported license) Emboldened by the tremendous success of the '55 Chevy, Cole began pondering the idea of a smaller companion model for Chevrolet, along the lines of the old Cadet. The business case for such a car was still not strong, but despite the failure of the Kaiser, Willys, and Hudson compacts, the small car market was showing signs of life. Volkswagen, which had sold fewer than 300 cars in America in 1950, was beginning a period of spectacular growth. Its sales increased by a factor of ten from 1954 to 1955, and expanded almost five-fold for 1956. Moreover, sales of AMC's Rambler, which now had the domestic compact market almost to itself, were beginning to rebound. Beyond the marketing considerations, Cole was fascinated with the engineering possibilities of an all-new small car. Even while they were building tanks in Cleveland, Cole, Barr, and Hansen had spent their spare time brainstorming ideas for radical new cars. At the time, such talk had been only an intellectual exercise, but they now had the opportunity to explore those ideas more fully.  Among the novelties of the all-new 1955 Chevrolet line was the sporty two-door Nomad wagon, part of the top-of-the-line Bel Air series. It was the most expensive '55 Chevy, over $300 more than a standard four-door wagon, so sales were limited, but it's coveted by modern collectors. The old Stovebolt Six was standard, but most buyers opted for the new 265 cu. in. (4.3 L) V8, which had 162 gross horsepower (121 kW); 180 hp (134 kW) with the optional four-barrel carburetor and dual exhausts. In 1955, Cole asked Maurice Olley, Chevrolet's director of research, to examine various powertrain configurations, including front-engine/rear-drive (FR), front-engine/front-wheel-drive (FF), and rear-engine/rear-drive (RR) layouts. The FR configuration was never seriously considered, mainly for packaging reasons; a conventional prop shaft and rear axle would have taken up too much space. Front-wheel drive was quickly discarded, as well, in part because most FWD cars of the time had abominably heavy steering without power assistance. The rear-engine, rear-drive (RR) layout, used by Volkswagen, Renault, and Fiat, among others, offered packaging, weight, and traction advantages, with the prospect of much easier steering. That dovetailed with Cole's thinking: he had been interested in rear engines since at least 1941, and he had even developed an experimental rear-engine Cadillac shortly after the war. With that decision, other parameters for the new car began to take shape. Cole's team quickly decided that water cooling was impractical with an RR layout, requiring a new air-cooled engine. The rear-engine layout, in turn, required the use of independent rear suspension, while weight and space considerations called for monocoque construction, a real departure for Chevrolet; although GM's European Vauxhall and Opel subsidiaries had adopted unitary construction in 1937, all of the corporation's North American cars were body on frame. The upshot was that the new car would be truly all new -- the closest Chevrolet had come to a clean sheet of paper in over 20 years. DOWN UNDER AND TO THE REARIn July 1956, Ed Cole took Tom Keating's place as vice president and general manager of Chevrolet, promoting Harry Barr to chief engineer. He could have taken that opportunity to propose the rear-engine compact idea to senior management, but Cole probably recognized that at that point, the corporation was unlikely to approve any compact car proposal, much less one as radical as Cole had in mind.
To keep senior management from learning of the rear-engine car before he was ready to make a formal presentation, Cole disguised it as a development program for Holden, GM's Australian subsidiary; in the fifties, Chevrolet regularly did R&D work for both Holden and Opel, so it was a plausible cover story. Cole went so far as to order Holden stationery and purchase order forms, and components developed for the project carried Holden parts numbers. Even the styling development was assigned to Ned Nickles' Experimental group, rather than the Chevrolet studio.  In an era of phony vents and faux scoops, the slots on the Corvair's decklid were functional, playing a vital role in engine cooling. Even so, their placement was dictated by styling, not engineering -- the fact that they happened to be positioned correctly for cooling purposes was a happy accident. Perhaps the most challenging aspect of the new car's design was the engine. Project engineers Al Kolbe and Robert Benzinger briefly considered a four-cylinder engine, but concluded that it would not be smooth enough for American tastes. For packaging reasons, they eschewed inline sixes in favor of a horizontally opposed engine, which also offered good balance without the need for counterweights. This was not Chevrolet's first venture into air cooling. Back in the early 1920s, research boss Charles Kettering had developed a unique "copper-cooled" four, which was launched -- against the advice and better judgment of Alfred P. Sloan, then on GM's advisory committee -- in early 1923. The engine was both difficult to assemble and disastrously unreliable, and fewer than 800 cars were built. Only about 100 of those were actually sold, all of them soon recalled. According to legend, many were dumped into Lake Erie, although a small handful survived; one is at The Henry Ford in Dearborn, Michigan, another is at the National Automobile Museum in Reno, Nevada, while the engine of another is part of GM's Heritage Collection and the body of a fourth car is displayed in the Buick Gallery and Research Center at the Sloan Museum in Flint.  The Corvair's engine, which Chevy dubbed "Turbo-Air," initially had a displacement of 140 cu. in. (2,287 cc), making 80 gross horsepower (60 kW) and 125 lb-ft (169 N-m) of torque with two single-throat carburetors. For 1961, it was bored 1/16th of an inch (1.59 mm), bringing displacement to 145 cu. in. (2,373 cc), presumably to give it nominal superiority over the 144 cu. in. (2,365 cc) engine in Ford's Falcon; its rated output did not change. Note the "mule-drive" V-belt. Early cars tended to throw their fan belts above 4,000 rpm, but this was resolved midway through the 1960 model year by the use of deeper pulleys. With an air-cooled flat six, however, Chevrolet was in largely uncharted territory. Although air-cooled twos and fours were common enough in motorcycles and European cars, flat sixes were very rare; Porsche's 911 was still years away. Kolbe and Benzinger soon found that an air-cooled flat six was a very different proposition than a flat four, with unique cooling and exhaust requirements. They studied contemporary six-cylinder aviation engines, but they found few useful precedents for mass-production automobiles. To keep the engine's weight under control, Ed Cole wanted it to be all aluminum, cast in two mirrored halves, with a high-silicon alloy (akin to the A390 alloy later used in the Chevrolet Vega) that would obviate the need for cylinder liners. That proved beyond Chevy's manufacturing capabilities, so the final design had detachable, cast-iron cylinder barrels, with an aluminum crankcase and aluminum heads with cast-in intake manifolds. Unlike most European engines of the time, it had hydraulic lifters. To keep overall height as low as possible, the engine used a big horizontal cooling fan, driven by a 'mule-drive' fan belt. In production form, the complete engine weighed 294 lb (133 kg) with automatic transmission flex plate and torque converter housing, 332 lb (151 kg) with clutch and flywheel -- light compared to contemporary inline sixes, but 78 lb (35 kg) over its original design target.  Originally, all Corvairs were to have Powerglide as standard equipment, but the sales organization balked at the expense, requiring the hasty development of a manual clutch and flywheel and a three-speed manual transaxle. Surprisingly, Powerglide was no particular handicap to performance -- Road & Track found that an automatic Corvair was slightly quicker than a three-speed car to 60 mph (97 km/h) -- and it was more pleasant to drive than the standard stick shift. The Corvair Powerglide had no Park position, however; automatic Corvairs had to rely on the handbrake. The engine's position precluded the use of a live axle rear suspension, common to all fifties Chevrolets, including the Corvette. Robert Schilling, who replaced Maurice Olley as director of research in early 1956, developed a modified swing-axle suspension, adding semi-trailing arms to counteract some of the swing axles' inherent oversteer. The goal was to preserve the advantages of a swing-axle suspension (simplicity and low cost), while mitigating some of its drawbacks. As we'll see, it was not entirely successful.
Comments (35)
Please do not post copyrighted content or images you don't own!
User comments do not necessarily reflect the opinions of Ate Up With Motor, and we accept no responsibility for their content. Publication of a comment does not constitute Ate Up With Motor's endorsement of any opinion, product, or service. Please click here to read our Comment Policy. Joomla components by Compojoom
|
Yeah, to all intents and purposes the prototype Chev Cadet became our beloved Holden 48/215 or sometimes referred to as the "FX".