1954 Chevrolet Corvair


The 1954 Corvair’s fastback styling with chopped off tail was influenced by European designs. In Europe, designers were more conceirned about aerodynamics than American designers were. Note the hood vents and front fender “gills”, wich were both scrapped on the production Corvette. Like its siblings, the Corvair used the same front design, though it also sported ribbed air intakes on the hood that routed fresh air to the interior and fender vents that allowed heat to escape the engine compartment. In typical Corvette fashion, the Corvair also had a wraparound windshield, with nearly vertical A-pillars like the Nomad, but without the wing windows. The roof was aircraft-inspired, sweeping back and tapering gracefully, eventually ending at the chrome-trimmed license plate housing, which resembled a jet-fighter exhaust port.

The roof was also interesting in a couple of other ways. First, it gave a glimpse of the quarter window and C-pillar treatment of the 1958 Chevrolet line, much like the Biscayne did a year later. Secondly, the addition of a fastback roof did not alter the Corvair’s interior layout. One would have expected that it would have had a finished-off cargo area, perhaps even equipped with fitted luggage, as was a common practice with sports cars at the time. Instead, the body appeared to have the roof grafted right on to a production Corvette, as there is no storage area behind the seats. The stock trunk area is used with a decklid contoured to the new roofline. The seats had the production fiberglass divider between them, just like a stock Corvette roadster. The area is even body-colored, which actually makes for a very attractive, albeit unusual interior layout for a closed coupe. The remainder of the interior is largely stock, with custom white seat covers and chromed interior C-pillar trim pieces.

Unfortunately for this particular machine, it was the only one of the three that did not reach production in some form. With Corvette sales becoming sluggish during the 1954 model year, it was seen by product planners as too high a gamble. The time for a Corvette fastback eventually did come, though nearly a decade later and on a new-generation machine.

The Chevrolet Corvair is a automobile produced by the Chevrolet division of General Motors from 1959 to 1969, for the 1960–1969 model years. The Corvair was offered in a wide range of body styles, including four-door sedans, two-door coupes, convertibles, and station wagons. In addition, it was built as a compact van similar to the Volkswagen bus, with styles including a pickup, panel van, and a passenger van called the Greenbrier. The cargo floor was raised above the rear engine, and some pickups featured an unusual side-loading ramp.

The Corvair — like the Ford Falcon, Studebaker Lark, Nash Rambler, and the Plymouth Valiant— was one of the first of a new compact class. These were offered in response to the small, sporty and fuel-efficient automobiles being imported from Europe by Volkswagen, Renault and others.

But the Corvair stood out with its significantly different engineering approach from other American offerings. The Corvair was part of GM’s innovative Y-body (“Z”-Body from 1965-on) line of cars, but this was by far the most unusual, due to the location and design of its engine. It was an air-cooled flat / opposed rear-engined vehicle inspired by the Volkswagen Beetle and the Porsche 356. The 1948 Tucker Torpedo had also used this layout to mixed reviews. Most other compacts such as the Chevy II / Nova, and later, the subcompact Vega, were smaller versions of conventional automobiles with in-line water-cooled front-mounted iron 4 or 6 cylinder engines. In contrast, the Corvair’s powerplant was an aluminum, air-cooled 140 in³ (2.3 L) flat-6 engine. The first Chevrolet Corvair engine produced as little as 80 hp (60 kW). Later versions developed as much as 180 hp (134 kW), comparable to V6 engines of the 1980s.

Although the Corvair was initially marketed as an economy sedan, with the development of a coupe, it was offered as a sporty sedan before the Mustang became popular in the compact segment. Its final design evoked the later Camaro, and is considered by many[weasel words] to still look contemporary in the 21st century.

History
Corvair convertible
The Corvair’s innovative flat-6 engine left room for the spare tire, creating even more room in the forward trunk.

The Corvair name originated as a fastback show car in 1954, which, like many Chevrolet concept cars of the period, including the Chevrolet Nomad and Chevrolet Impala, was based on the Corvette. The design was championed by Ed Cole, Chevrolet’s chief engineer in the early 1950s and general manager in the late 1950s, as an answer to the growing popularity of small, lightweight imported cars.

Design began in 1956 under the auspices of Ed Cole; the first vehicles rolled off the assembly line in late 1959 as part of the 1960 model year. For 24 hours, two Corvairs were tested at the Riverside International Raceway in Riverside, California. One car rolled over, but the other completed the drive, only losing a quart (0.946 L) of oil.The Corvair was introduced to the public early in 1960, as actress Shirley Bonne unveiled the first model.

The Corvair represented a major breakthrough in unibody construction for mass-produced Detroit vehicles, the most successful automobile of this type up to that time, with 1,786,243 cars being produced between 1960 and 1969. Among its many other forward-thinking and breakthrough technologies for its day, the Corvair was built from uniform molds and relied on the shaping of the glass and doors for help with structural integrity[4]. Convertible versions needed special supports welded underneath to compensate for the missing shape on the top.

The Corvair enjoyed a ten model year run, and was finally discontinued in May 1969 due to plummeting sales. A variety of factors contributed to the model’s 96-percent drop in sales from 1965 to the last 1969 models. The Corvair faced increasing competition from the Ford Mustang and other “pony cars” — ironically, a market pioneered by the 1960 Corvair Monza. Safety issues were raised, especially by Ralph Nader’s 1965 book Unsafe at Any Speed. The car’s design was costly to produce and did not command a premium price on the showroom floor. Engineers experienced difficulties adapting the basic engine design to the tighter emissions standards proposed for 1972. Lastly, a general lack of interest at General Motors, including an almost complete lack of advertising from 1967 onwards (the company’s “by-request-only” 1969 Corvair brochure was a mere four pages long, and the 500 Sport Coupe wasn’t even illustrated) contributed to the model’s demise.

The Corvair was a successful model for Chevrolet, with annual unit sales exceeding 200,000 for many years. Chevrolet deliberately designed the Corvair as a radical departure from the conventional Chevrolet. The rear engine offered enormous packaging and economy advantages, providing the car with a lower silhouette, flattening passenger compartment floor, obviating the need for power assists, reducing the need for air conditioning (due to the absence of engine heat blowing over the passenger compartment), and offering dramatic improvements in ride comfort, traction and braking balance. The radically different design also attracted customers from other makes, primarily imports. This was an important, and often under-emphasized, cause of the Corvair’s success.

Unlike the Falcon and Valiant nameplates, whose conventional designs tended to poach customers from the cheaper but profit-driving full-size models from their respective manufacturers, the Corvair siphoned customers from makes such as Volvo or VW. Because such customers had not been likely to contemplate a larger Chevrolet Biscayne (which cost only slightly more), each Corvair sold did not translate into a Biscayne that was lost. This was in direct contrast to the situation at Ford, where the Falcon nearly ate its maker alive by stealing sales from the basic large Ford sedan. Corvair sales were almost entirely “extra business” for Chevrolet.

Corvair was named Motor Trend magazine’s Car of the Year for 1960.

The early four door 1960 models, the 500 and the 700, were conceived as economy cars offering few amenities in order to keep sticker prices down for Chevrolet customers. Powered by an 80 hp (60 kW) engine and unsynchronized three speed manual or two speed Powerglide automatic transmission, the Corvair was less powerful than other cars in its class; however, the horsepower and torque fit the size of the car rather well. Despite the relatively expensive and unique power train, the car sold for around $1,500 for a base model 500.

Introduced in January 1960, two-door models boasted a fold-down rear seat for added storage capacity, which was greatly needed as the spare tire was stowed in the forward trunk compartment. The passenger compartment was heated by a gasoline heater mounted next to the spare tire in the luggage compartment. While it offered immediate hot air, customers complained of what they thought might be decreased gas milage on cold days and through long winters. Chevrolet redesigned the heating system for the 1961 model year, yet left it up to customers to choose the gas heater until the end of the 1964 model year.

Monza

The line quickly grew from utilitarian bench seat sedans and coupes to the more plushly appointed bucket seat interiors of the 900 line now called Monza. It hit showroom floors in the Spring 1960. Two available options on Monza were a more powerful engine, rated at 95 horsepower (71 kW) thanks to a more radical camshaft paired with low-restriction exhaust, and the introduction of a fully synchronized four speed transmission.

Despite its late introduction, the Monza sold 12,000 units, making it one of the most popular Corvairs.

1961 Chevrolet added an optional four-speed manual transmission (late in 1960, few produced prior to 1961 introduction) to augment the standard three-speed manual and optional two-speed Powerglide automatic. The Corvair engine received its first size increase to 145 in³ courtesy of a slight increase in bore size. The base engine was still rated at 80 hp (60 kW) when paired with the manual transmissions and 84 hp (63 kW) when mated to the optional automatic transmission in Monza models. The high-performance engine was rated at 98 hp (73 kW). To increase luggage capacity in the front the spare tire was relocated to the engine compartment in cars not ordered with All Weather air conditioning and the gasoline heater was replaced by a system of ducts that redirected warmed air from the cylinder heads to the passenger compartment. The gasoline heater remained available as an option through 1964.

Corvair was the first of the compacts to offer factory air conditioning, as a mid 1961 option introduction. The large condenser lay flat atop the horizontal engine fan. A large, green painted reverse rotation version of the standard GM Frigidaire air conditioning compressor was used, and an evaporator housing was added under the dash with integrated outlets surrounding the radio housing. All Weather Air Conditioning was not available on wagons, Greenbrier/Corvair 95, or the turbocharged models introduced later due to space conflicts in those body styles.

A station wagon, the Lakewood, was also added to the lineup in 1961. This was similar in layout to the Volkswagen Squareback also introduced that year which placed a flat engine under the cargo floor. It contained a total of 68 ft³ (1.9 m³) of cargo room — 58 in the main passenger compartment, and another 10 in the “trunk” under the hood.

That same year, Chevrolet also introduced the Corvair 95 line of light-duty truck, which used the Corvair driveline and were forward-control, with the driver sitting over the front wheels, as in the Volkswagen Type 2. The Corvan model was available in myriad configurations as both a panel van and a window van. There were also two models of pickup available. The Loadside was a fairly typical pickup of the era, except for the rear engine, forward controls, and a strange pit in the middle of the bed, The more popular pickup was the Rampside model, which, as its name implies, had a large fold-down ramp on the side of the pickup bed. Rampsides were used by the Bell System because of the ease with which cable reels could be rolled in and out of the bed. Fleet sales of Corvair commercial vehicles were poor due to an approximately $100 premium over competitive Ford products: If you bought 25 trucks, you essentially got one extra Ford for free. This disadvantage would seriously affect Corvair 95 sales, and ultimately cause the line to be discontinued in favor of a basic Chevy II-based panel truck in 1964.

The Greenbrier Sportswagon used the same body as the Corvan with window option, but was marketed as a station wagon like the Lakewood, and was available with trim and paint options similar to the cars, arguably making it the first American minivan.

Continuing from the end of the previous year was the Monza, heavily promoted and sometimes considered “the poor man’s Porsche.” The Monza was expanded to a four-door as well as a two-door coupe and garnered around 144,000 sales.

1962 – 1963
The Corvair’s innovative turbocharged engine

In 1962, Chevrolet introduced the 150 hp (112 kW) turbocharged Monza Spyder option for Monza coupes and convertibles mid year, making the Corvair one of the first two production automobiles to come with a turbocharger as a factory option, with the Oldsmobile F-85 Turbo Jetfire of the same year. The 500 station wagon was dropped in favor of the Monza wagon at introduction, however all station wagons were discontinued mid year to create more capacity for new models like the convertible and Chevy II. Metallic brake linings and a heavy duty suspension consisting of a front anti roll bar, rear axle limit straps, revised spring rates and recalibrated shock absorbers were introduced as optional equipment and recommended for Spyders. Monza Spyder featured a multi-gauge instrument cluster which included a tachometer, cylinder head temperature gauge and intake manifold pressure gauge in addition to the turbocharged high performance engine.

The 1963 model year saw the end of the Loadside pickup, and the availability of a long 3.08 gear for improved fuel economy, but the Corvair otherwise remained largely carryover with minor trim and engineering changes (self adjusting brakes) from 1962.

Significant engineering and safety changes occurred in 1964, while the bodies and models available remained the same.

The lineup remained relatively unchanged for the 1964 model year, with the exception of the engine growing from 145 to 164 in³ (2.3 to 2.7 L) due to an increase in stroke; the base power growing from 80 to 95 hp (60 to 70 kW), and the high performance engine growing from 95 to 110 hp (70 to 80 kW). The Spyder engine remained rated at 150 hp (112 kW) despite the displacement increase of the engine. The Rampside pickup was discontinued at the end of the model year.

1964 also saw a critical improvement in the Corvair’s suspension; the car’s swing axle rear suspension was tamed by use of an additional transverse leaf spring carrying a high proportion of the rear weight in an effort to diminish rear roll stiffness and foster more neutral handling attributes. Spring rates were much softer at both ends of the car in 1964 compared to previous models, and the heavy duty suspension was no longer optional although all models now had an (even larger) front anti roll bar standard. Brakes were mildly improved by finned rear drums.

However, a young lawyer named Ralph Nader had written a book called Unsafe at Any Speed in which the 1960-63 Corvair (accused by Nader of a greater tendency to cause loss of driver control, spin out or even roll over in many situations) was used as a dramatic case study. The Nader book, which was published in 1965, came as a blow to sales of the Corvair line. The sporty, inexpensive Ford Mustang, based on the conventionally designed Ford Falcon and introduced in April 1964 in response to the market pioneered by the Corvair Monza, also hurt Corvair sales.

1966 Chevrolet Corvair

A dramatic redesign of the Corvair body and suspension and two powerful new engines came in 1965. The new body style showed influence from Chevrolet Corvette Stingray and the 1963 Buick Riviera, with ‘coke bottle styling’ that set the trend for GM cars for the next fifteen years- foreshadowing the 1967 Chevrolet Camaro that eventually replaced the Corvair. Many consider the second generation to still look contemporary in contrast to the first generation body. A new fully independent suspension similar to that used on the Corvette replaced the original swing axle rear suspension. Car and Driver magazine’s David E. Davis Jr. showed wild enthusiasm for the 1965 Corvair in their October 1964 issue. For the first time, none of the passenger cars had a “B” pillar, making all closed models true hardtops.

“And it is here too, that we have to go on record and say that the Corvair is – in our opinion – the most important new car of the entire crop of ’65 models, and the most beautiful car to appear in this country since before World War II.”

“When the pictures of the ’65 Corvair arrived in our offices, the man who opened the envelope actually let out a great shout of delight and amazement on first seeing the car, and in thirty seconds the whole staff was charging around, each wanting to be the first to show somebody else, each wanting the vicarious kick of hearing that characteristic war-whoop from the first-time viewer.”

“Our ardor had cooled a little by the time we got to drive the cars – then we went nuts all over again. The new rear suspension, the new softer spring rates in front, the bigger brakes, the addition of some more power, all these factors had us driving around like idiots – zooming around the handling loop dragging with each other, standing on the brakes – until we had to reluctantly turn the car over to some other impatient journalist. We were actually annoyed about having to drive the new Sting Ray and the new Impala SS with a great, storming 409 to propel it”

“The ’65 Corvair is an outstanding car. It doesn’t go fast enough, but we love it.”

Many new options and refinements appeared in the beautiful[7] new 1965 redesign. Fully integrated in-dash All Weather Air Conditioning, a much better heater system, larger brakes borrowed from the Chevelle, a stronger differential ring gear, a Delcotron alternator and significant carburetor and small chassis refinements all occurred. AM/FM radio, FM stereo, telescopically adjustable steering column, and a Special Purpose Chassis Equipment (“Z17″) handling package, consisting of a special performance suspension and quick ratio steering box, were significant new options that became available for 1965.

The previous 150 hp (112 kW) Monza Spyder was replaced by the normally-aspirated 140 hp (104 kW) Corsa and the 180 hp (134 kW) Turbocharged engine. The Corsa came standard with an instrument panel featuring a 140 mph (230 km/h) speedometer with resettable trip odometer, a 6,000 rpm tachometer, cylinder head temperature gauge, analog clock with a sweeping second hand, a manifold vacuum/pressure gauge and fuel gauge. Powerglide automatic transmission was not offered on the Corsa, however the Corsa’s standard 140 hp (100 kW) four-carburetor engine was available for $79 in the 500 and Monza series Corvairs with Powerglide, if so desired by a customer. The standard equipment Corsa 140 hp (104 kW) engine was notable for the fact that the engine used 4 single-throat carburetors, larger valves, and dual exhaust — the factory’s response to a modification hot-rodders had been making since the car first appeared; it was available as an option on other Corvair trim levels. The base 95 hp (71 kW) and 110 hp (82 kW) high performance engines were carried forward from 1964 for the 500 and Monza models.

By this point, the more utilitarian station wagon, panel van, and pickup body styles had all been dropped in favor of the sportier coupe, hardtop sedan and convertible styles. 1965 would be the last year for the Greenbrier window van, which was retained only because of a few fleet orders, with 1528 being built. Chevrolet replaced the Corvair-based vans with the Chevrolet Sportvan/GMC Handi-Van, which used a traditional front engine/rear drive axle borrowed from the Chevy II.

1966 – 1969

The 1966 lineup remained essentially unchanged from 1965, and sales began to decline as a result of Nader’s book, the very popular new Mustang that offered V8s up to 271 hp (202 kW) compared to Corvair’s 180 hp (130 kW) top powertrain, and rumors of the upcoming “Panther’- the code name for the forthcoming 1967 Camaro slated as the replacement for the Corvair in the sporty car market. The sales decline was also accelerated by a decision at GM to discontinue further development of the Corvair. One change of note was a more robust 4 speed synchromesh transmission for 1966, using the standard Saginaw gear set with 3.11:1 first gear ratio used by other GM 6 cylinder vehicles. The new 3 and 4 speed transmission was capable of handling more stress, though generally much more truck-like in operation than the prior 4 speed transmission which was modeled more along the lines of a Warner, but also a Saginaw product. It was a great improvement over the older 3 speed transmission, having a synchronized first gear. Also, the gear ratios were carried over from other GM cars, and were not optimal for a street-driven Corvair. A small flexible plastic air dam (“spoiler”) was installed below the front apron to conceal the front suspension and underbody, and lessen crosswind sensitivity to virtually nil. It is a popular retrofit to the 1965 models both for functional and aesthetic reasons. Corvair fans can easily tell the difference between the 1965 and ’66 models by the taillights; the ’66-’69 lenses protrude further from the bezels, and the backup light is less obvious, located inside the inboard lens. In front, the Chevy emblem is painted red on the ’65s; ’66-’69s are blue. ’65 models carried “Corvair” script on the right side of the hood; for 1966, the script was moved further down to the “grille” area, just to the left of the right headlight bezel. The Monza emblem featured a thinner vertical bar.
1967 Corvair Monza

In 1967 the Camaro was introduced and the Corvair line was trimmed to the base 500 sedan and coupe, and the Monza sedan, coupe and convertible. The 140 hp (104 kW) and 180 hp (134 kW) engine options were deleted as well, although the 140 hp (100 kW) option would be later reintroduced as a regular production option and would remain available until Corvair production ended. This model year was the first equipped (along with all other domestic GM lines) with true collapsible steering columns, a final response to one of the most valid safety criticisms. GM introduced a 50,000-mile (80,000 km) engine warranty on all 1967 models, including the Corvair. Dual circuit master cylinder with warning light, nylon reinforced brake hoses, stronger steel (instead of aluminum) door hinges and soft contoured instrument panel knobs and a vinyl edged day/night mirror were all made standard equipment as well.

In 1968 the line was trimmed even further by discontinuing the four door hardtop models, leaving just three models; 500 Sport Coupe, and Monza Sport Coupe and Convertible. Sales were down to 15,400. All Weather air conditioning was dropped as an option, due to concerns about thermal loading added by the now-standard air injection reactor (“smog pump”) which probably hurt sales as factory air became more popular generally in automobiles. Additional safety features, including side marker lights, and shoulder belts for closed models, were fitted per the Federal government’s requirements.

According to researchers such as noted GM historian Dave Newell, GM had already planned on ceasing Corvair production after the 1966 model year to make way for the Camaro. But the timing of Nader’s book turned out to be an inconvenience. Not wanting to appear as though they were buckling to Nader’s pressure, GM kept the Corvair in production for another three years. The only developmental changes made were to keep in line with government safety and emissions requirements. Another indication of the Corvair’s imminent demise was when the 1969 models were introduced: GM equipped its 1969 models one year ahead of Government requirements, with a steering column-mounted, anti-theft ignition switch, and a new, square-shaped ignition key. In 1969, Corvairs got the new key but were the only GM cars to retain the ignition switch on the dashboard, no doubt due to the lack of interest by GM engineering to adapt the Corvair steering column accordingly. How those last 1969 Corvairs were assembled (and the press event held by Chevrolet when car number 6000 rolled off the assembly line) is an interesting part of the Corvair story.

1969 Corvairs and Novas were being assembled at the same facility in the Chevrolet/Fisher plant complex in Willow Run, Michigan. However, demand for Novas was high and almost nonexistent for Corvairs, so a decision was made in November, 1968, to move Corvair assembly to a special area in the plant, dubbed the “Corvair Room,” making Corvairs built between that time and May 14, 1969 essentially hand-built (once the bodies were delivered from Fisher Body). A number of well-known Chevy collectors and GM executives expressed interest in purchasing the last Corvair, number 6000, but GM management decided that the Olympic Gold Monza hardtop would not be sold. Most accounts relate that GM scrapped it shortly after it was built. Representatives from the press, along with corporate bigwigs, were present at the small ceremony when car number 6000 got its final fittings and drove off the line to where railroad cars full of new ’69 Novas were ready to be shipped to dealers. Reaction to the death of this sporty car was mixed, and extended to both ends of the spectrum, from sadness and regret that such a fine car couldn’t make it in the marketplace, to sharp criticism of Chevrolet’s decision to continue building the car at all. It should be noted that GM’s policy has always been to forbid non-employees from visiting their assembly plants, and certainly, photographing the area. It was the Corvair that again, proved to be the exception.

General Motors did have plans for a 1970-on model Corvair, essentially a re-skin of the 1965-69 body with new exterior sheetmetal. The car likely would have debuted as a “1970 1/2″ model, much as Corvette and Camaro did for 1970. The overall appearance of this third generation Corvair was very similar to the 1973 GM A Body intermediates– particularly the 1973 Pontiac Grand Am. It retained Corvair proportions, with a rounded sweeping body, terminating in a tapered tail with a glassy roof, featuring fixed quarter windows. This program progressed past the point of full scale clay models before being dropped in early 1968. One interesting project at GM was the Turbo Hydramatic 350 transmission, introduced in the 1968 Camaro and later adopted by most Chevrolet models. It was laid out in a manner that would permit its use in the Corvair, unlike the Turbo Hydramatic 400 and most other designs. Had the 1970-on Corvair been built, it is clear this transmission would have been adapted for the Corvair. The last word on the 1970+ “third generation” Corvair was, “Mr. Cole (GM President Ed Cole, ex-Chevrolet General Manager during Corvair development) is not enthused about this program…”

In what may be the automotive industry’s greatest irony, NHTSA, the federal agency created from Nader’s consumer advocacy, investigated the Corvair and issued a report in 1971 clearing the car’s design, two years after the car went out of production.

Part of Nader’s evidence against the Corvair was a promotional film created by Ford Motor Company, in which a Ford test driver purposely turned the Corvair in a way to make it spin around. Such films were not uncommon. GM also had films showing the Ford Econoline pickups standing on their noses under heavy braking.

Engineering
This article or section is written in an informal style and with a personally invested tone. It reads more like a story than an encyclopedia entry. To meet Wikipedia’s quality standards and conform with our Neutral Point of View policy, this article or section may require cleanup. The talk page may have more details. Editing help is available. (December 2007)

The Chevrolet Corvair engine, unique for an American car, presented a different set of requirements for mechanics, many of whom treated the engine in the same way as they would an engine of normal design, leading to problems.

An engineering weakness not generally highlighted related to fumes and gases entering the passenger area via the heater system, a problem endemic to an air-cooled engine that uses heat radiated from the engine directly to heat air for the passenger compartment. Carbon monoxide and other noxious or deadly gases could enter the passenger areas if exhaust system gaskets aged or failed using this system, since the gaskets were inside the heater box air intakes and air for engine cooling was used for passenger–compartment heating when the heater was on (or leaking). The 1960 model Corvairs used a GM Harrison division gasoline heater located in the front trunk area as its standard heater, similar to the Eberspächer heater offered as an auxiliary heater by Volkswagen as a dealer-installed option. This feature became optional in 1961 and was dropped in 1965 due to weak consumer demand.

Chronic oil leakage from the pushrod tubes, caused by GM’s poor choice of pushrod tube seal material, also contaminated the passenger heating air. That air might also become noxious if a 6-inch (152 mm) wide rubber seal almost 16 feet (5 m) long, located between the engine assembly and the body, was not maintained in like-new condition. Another common problem in the earlier years was oil leakage caused by dissimilar metal thermal expansion on the aluminum–and–steel engine. Chevrolet wrestled with several problems of this nature the entire time the Corvair was in production with varying degrees of success. Sandwiching cast iron cylinders between an aluminium case and alloy heads is highly magnified by putting another cylinder on each bank.

The interior air would also be contaminated if the voltage regulator allowed an over-voltage condition and the original battery vent hoses were not attached. The battery, which was mounted in the engine compartment, could emit hydrogen if overcharged. Chevrolet installed special battery caps and hoses that vented the battery to air outside the engine compartment, but these were often discarded by owners during the car’s life.

The Volkswagen Beetle (Type I), another automobile with an air cooled engine, had a heater system which better isolated fresh air from engine cooling air fumes, and was only susceptible to carbon monoxide contamination from the two heat exchanger to muffler seals at the rear of the engine, as opposed to the eight exhaust joints in the Corvair system. This air contamination problem is illustrated by the fact that many American cities’ taxi regulations had prohibited air-cooled engine cars from being used as taxicabs when they derived their heated air from engine exhaust heat, decades before the Corvair and VW Beetle entered the market.

Another problem that the Corvair did not share with Type I Beetles was the fan on top of the engine. The fan and generator were operated by a belt on the rear of the crankshaft. It had to turn around two ninety degree pulleys (each twisting it sideways) to get to the fan pulley, and was described, at the time, as the worlds longest belt.

A criticism in Lawyer Ralph Nader’s 1965 book concerned the steering column design. Like most cars of its era, the Corvair’s steering column was rigid and could impale the driver in a front-end collision. While the Corvair’s steering box was mounted ahead of the front cross-member, it was well behind the frame horns, in what would later be called a “crumple zone,” and could, in a severe front-end collision, push the steering column and steering wheel toward the driver. In practice, most driver chest injuries were sustained due to the lack of a shoulder belt, rather than steering column intrusion. Any increase in risk of injury due to steering column intrusion in a front-end collision was, however, more than offset by the absence of an incompressible engine and transmission in the front of the vehicle, which commonly intruded into passenger compartments on vehicles of the era. Chevrolet, aware of Nader’s criticism, changed the steering shaft to a two-part design with a frangible joint late in the 1965 model year, and a collapsible steering column was provided in 1967, towards the end of the model’s life span.

The criticism of the 1960-’63 Corvair handling was not entirely groundless. Although it was a competent handling vehicle as delivered from the factory, with characteristics quite similar to many imported cars, such as Mercedes and Volkswagen, which also used swing axle suspensions with similar handling attributes, there was room for improvement. Advertising in 1960 from domestic competitors showing the results of shooting an arrow weighted at the rear end missing its target widely did little to foster confidence in many minds about the stability of the car.

Chevrolet had tailored the handling of the Corvair by using very wide tires for such a light car (6.50-13, considered wide at the time, even contemporary Corvette used only a 6.70) to bear the weight of the rear and reduced front pressures by about 11 psi to increase front slip angles to balance traction and maintain confident control. If this pressure difference was not maintained, the handling could become dangerous. In very hard cornering, the rear slip angles would exceed the front slip angles, and could lead to oversteer at high speeds.

Swing axles were a common suspension design during the Corvair era. The advantages of swing axles are numerous, good handling not being one of them ; very compact packaging, tremendous strength and durability on rough surfaces, very good isolation of road harshness and a very smooth ride due to the camber changes forcing the tire carcass to absorb blows sideways as well as radially on severe bumps.

The primary deficiency of swing axle suspensions is they create a high “roll center;” the theoretical point that the cars center of mass pivots around- as it leans in cornering. A high roll center increases body roll in cornering; however, it reduces sensitivity to uneven roads and crosswinds. Having a high “roll center” transfers a large amount of weight to the outboard tire during cornering. Pre-1965 Corvair has a rear roll center approximately 13″ above the road surface and front roll center just slightly below the road surface. This concentration of roll loading on the rear wheels means that as the cornering force increased, the weight was transferred to the already heavily loaded rear tire. The cornering force combined with the already heavily loaded rear tires (from the weight of the engine) increased its slip angle, and could eventually pushing the car into lift-off oversteer

Chevrolet had considered adding a front anti-roll bar for the original 1960 car, which would have shifted a significant part of this weight transfer to the front outboard tire and reduced the rear slip angles considerably in severe cornering. Unfortunately, GM decided that the extra cost ($6 per car is often cited), with the confidence in tire pressures adequately compensating for the inclination for oversteer- led GM to delete the front anti–roll bar from production models (GM used different low front and high rear tire pressures to combat the oversteer). This decision would come back to haunt GM later. The anti–roll bar did become available as an option in 1962, and was made standard finally in 1964. The 1964 rear suspension was modified considerably with a transverse leaf spring carrying much of the rear weight and vastly softer coil springs. The redesigned 1965 suspension was a total solution, cutting the rear roll center down to half its previous height, using fully articulated half-axles that offered constant camber on the rear tires in all driving situations. Although much is said about ‘jacking’ (tendency for swing axle suspensions to go into very severe positive camber in extreme corners), the bias ply tires used at the time were very insensitive to camber and did not have severely reduce cornering grip (unlike radial tires which later became commonplace). Due to the swing axle design, the rear tires would undergo large camber changes during fast cornering, and the improvements in 1965 only improved this design element.

Contemporary Mercedes W120 Ponton sedans along with rear-engined Volkswagens, Renaults, Porsches and other cars used swing axles, with mixed results. As Corvair was designed to avoid terminal oversteer by using very low air pressure in the front tires, typically 15 to 19 pounds-force (85 N) per square inch, so that they would begin to understeer (increase slip angles faster than the rear) before the swing axle oversteer would come into play, this pressure was quite adequate for the very lightweight Corvair front end on the already quite wide tire. Owners and mechanics, either through ignorance of the necessity for this pressure differential between front and rear or thinking that the pressure was too low for the front, would frequently inflate the front tires to current “average” pressures. It should be mentioned that the Corvair is by no means unique in requiring dissimilar front and rear tire pressures for normal controllability; even the front–wheel–drive Cadillac Eldorado years later used very low rear pressures (16 psi) to balance handling. This may seem contrary to many ideas about a tires contact patch, but it’s important to remember how tires of different materials and sizes will be affected in dissimilar ways.

Wheel camber change on the early models created a “tuck under” and “air out” condition in one or both of the rear tires during hard cornering. According to Nader, a son of a member of the GM Board of Directors died in an early Corvair as a result of this characteristic. In this regard, Nader’s book, along with On a Clear Day You Can See General Motors by John Z. DeLorean and J. Patrick Wright, was highly critical of Ed Cole’s obsession with building and marketing a rear-engined, air-cooled car to sell at a low price.

Although Nader arguably overstated the severity of these handling problems, as was later claimed by U.S. National Highway Traffic Safety Administration investigators, DeLorean ultimately backed Nader’s findings in his book. Whatever the reason, Chevrolet did make changes to the suspension for 1964 models. GM added as standard what had previously been an option, namely, a transverse leaf spring extending between the rear wheels, to limit rear wheel camber change.

In 1965 the Corvair got a state–of–the–art fully independent rear suspension closely resembling that of the contemporary Corvette, and even sharing some components. Motor Trend referred to the 1965 model as “the first American production automobile on the road with fully-independent rear suspension, (the Corvette considered limited production).” These changes were, however, viewed by critics as an admission by Chevrolet of problems with the original design.

Scribbled on November 25th 2008 in Chevrolet, Chevrolet Corvair, robson.m3Rlin.org
Very Popular Posts Most Popular Posts Read This
  1. Dodge General Lee
  2. Ferrari Enzo
  3. Nike One Concept
  4. Audi A8 Racing
  5. Different Brand CDN
  6. BMW X6
  1. Tuning Car Different Brand
  2. Mustang Gt500
  3. Aube Concept
  4. Koenigsegg CCR
  5. Jeep RRenegade
  6. Porsche Mirage
  1. RIF
Copyright © 2006-2014 PC Mail Service. All rights reserved.PC Mail Service Contact: webmaster
Partner sites: Super Cool Bikes / Tuning / Szybkie i Grozne / www.jacobdybala.com / Robson Blog / Delphi Tips & Tricks /
Professional Chicago SEO, Web Design and Web Hosting / Professional Chicago Wedding Photographer / CNC Plasma Cutting Machines and Equipment