Chevrolet Vega

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Chevrolet Vega
Chevrolet Cosworth Vega
ManufacturerGeneral Motors
Also calledPontiac Astre
AssemblyLordstown, Ohio, United States
Sainte-Thérèse, Quebec, Canada
PredecessorChevrolet Corvair
SuccessorChevrolet Monza
Chevrolet Chevette
Pontiac Acadian (For the Astre.)
Pontiac Sunbird (For the Astre.)
Body style(s)2-door coupe
2-door station wagon
3-door hatchback
LayoutFR layout
Engine(s)122 CID Cosworth I4
140 CID 2300 I4
151 CID Iron Duke I4
Transmission(s)3-speed manual
4-speed manual
5-speed manual
2-speed automatic
3-speed automatic
Wheelbase97.0 in (2464 mm)
Length169.7 in (4310 mm)
ManualsService Manual
Pontiac Astre

The Chevrolet Vega was a subcompact car sold from 1971 through 1977. Available in sedan, coupe, station wagon, and sedan delivery body styles (officially referred to as the Notchback, Hatchback, Kammback, and Panel Express, respectively), it was based on the GM H platform. The 1975 to 1980 Chevrolet Monza coupe was based on the Vega, as was the restyled Monza wagon. The similar Pontiac Astre was available in Canada from 1973 through 1977, and in the U.S. from 1975 through 1977. The Vega was Motor Trend's Car of the Year for 1971. Production of the Vega totaled over 2.9 million vehicles, all built at the Lordstown, Ohio GM Assembly Plant.


Detroit's first attempt at confronting the entry-level imports and domestic small cars such as the Studebaker Lark and Rambler American in the fall of 1959 produced the compact class of cars, including the Ford Falcon, Plymouth Valiant and the ill-fated Chevrolet Corvair, each introduced as 1960 models. By the 1970s, while cars like the Maverick, Nova, Hornet, and Valiant had evolved into the smallest versions of the traditional 6 passenger American family cars, they were much larger than the subcompacts, and many were delivered with optional V8 engines. See also Nash Rambler and AMC Metropolitan (introduced in 1954).

The Vega was introduced as part of "Big Three" (GM, Ford, Chrysler) automakers entering a new subcompact car class in order to compete directly with the successful, but aging Volkswagen Beetle, as well as Japanese imports from Honda, Toyota, and Datsun. Its conventional four-cylinder rear wheel drive layout and unibody was similar to Japanese subcompacts, but somewhat larger for U.S. buyers. It used stamped upper and lower A-arms for the front suspension, along with a solid axle with coil springs, and stamped steel lower control arms in the rear. For 1976, a Panhard rod was added to the rear suspension, along with a torque arm which connected the differential housing to the transmission's tailshaft housing. GT and Cosworth Twin-Cam models added front and rear anti-roll bars, along with stiffer springs. The Vega's 97-inch (2,500 mm) wheelbase and 169.7-inch (4,310 mm) overall length was somewhat larger than the Toyota Corolla's 161.4-inch (4,100 mm) length and 91.9-inch (2,330 mm) wheelbase. See 1970 Honda automobile.

One innovation of the original Vega was that it was designed to be shipped vertically with its nose down. For example, the battery had fill caps at the back to prevent leakage during transit. Special rail cars known as "Vert-A-Pac" cars were built with hangers to carry the first Vegas to market in this vertical arrangement. One of the notable locations where these cars were unloaded was at the now defunct Sawtell Auto Ramps in Atlanta, Georgia, located on the former Southern, now Norfolk Southern mainline to Macon.

While in-tank fuel pumps had been used in some earlier Cadillac and Buick models, the H-Body platform (Vega, Monza) were the first high-volume GM vehicles to use an in-tank fuel pump, common with present-day fuel-injected vehicles. The car was also the first to use a "ventless" cabin ventilation system, dispensing with the then-common operable vent windows for a series of built-in exhaust vents on the trunk lid and low flow forced air through the climate control system.


Though often today dismissed as a failure, the Vega was initially a strong seller. Although outsold most years by the Pinto, Chevrolet sold over two million Vegas during its lifetime. Consumer Reports rated a 1971 Vega above the Pinto and the Gremlin, but had reservations about the Vega's workmanship with similar reviews for subsequent Vega tests through 1974 and a subsequent test of a similar Pontiac Astre in 1975.

Car and Driver awarded top pick to the Vega above five other cars including the Corolla, Pinto, Gremlin, Volkswagen, and an obscure Simca "because of its particular suitability to American driving conditions." It was the only car besides the shortened compact Gremlin that could cruise at 70 or above. Its long 2.53:1 axle ratio allowed a low 3,000 rpm at 80 mph (130 km/h). Its ride was judged to be plush with a comfortable seating position, though it lacked a traditional glovebox. The Vega was the fastest of the cars tested, taking 12.2 seconds to reach 60 mph (97 km/h), similar to a modern Toyota Prius.

Years later, Forbes, Popular Hot Rodding, The Truth About Cars, and other automobile magazines would name the Vega among the worst cars of all time.


Most Vegas were equipped with a new lightweight aluminum block 2.3 L "2300" SOHC I4. The standard engine used either a single-barrel carburetor which for 1971 produced 80 net or 90 gross horsepower. The two-barrel version of the 1971 engine produced 90 net or 110 gross horsepower. Starting in 1972, the manufacturers no longer published gross (on a test stand) figures. Also, from 1972 on, tightening emissions regulations meant that the one-barrel engine produced about 70 net horsepower. The two-barrel option boosted output to around 85 hp (63 kW). Early two-barrel engines used a Rochester carburetor, which was later replaced by a Holley-built 5210C staged two-barrel (one primary and one secondary), based on a Weber design.

Vega engines become infamous for their lack of durability which was often associated with their use of weight-saving aluminum cylinder blocks with cast iron heads. These blocks did not have traditional iron cylinder sleeves as a cost-saving measure[1], instead, a wear surface was created on the aluminum cylinder bores using the Nikasil coating process. This approach was not generally successful, the harder iron cylinders slowly wore away the aluminum block allowing hot combustion gases to bypass the piston seals, leading to premature engine failure. The block itself was designed in partnership with Lotus, who planned to use it as the basis for a inexpensive racing engine. However, Lotus never used the Vega block or anything similar. The high tech aluminum block had cast iron main caps, a cast iron crank, and an enormous cast iron cylinder head that weighed almost as much as the whole short block. The tall, top heavy, long-stroke Vega motor had major vibration problems, "cured" with huge rubber motor mounts. With the hood open and the engine idling, "it would be rocking and bouncing around like it was trying to escape." [2] Early models overheated due to poor cooling passage design. Overheating was a serious concern for Vega engines, since the lightweight engine block was of an open-deck design, and severe overheating would cause the cylinder barrels to warp and pull away from the head gasket, causing coolant leaks into the cylinders. The 2300 engine typically burned oil due to both heavy cylinder wear[3] [4], and poorly designed valve stem seals, and was both rough and noisy in operation. To try to counter low oil pressure-related failures, Chevrolet designed the Vega with an in-tank electric fuel pump which was wired through the oil pressure sender, so that low oil pressure would cause the fuel pump to shut off, stopping the engine. Also, for 1975, Chevrolet added a coolant level sensor in the right-hand radiator tank, which turned on a warning light if the coolant level dropped below a quart below full. The engine only lasted a few years, with a horrible service record, while Chevrolet claimed the service problems (scored cylinders, scored walls) were mostly due to improper maintenance.

The 1976-77 2300 engine received a new cylinder head design incorporating hydraulic lifters to replace the unusual taper-screw valve adjusters, factory iron cylinder liners, and better valve stem seals in the hopes of improving sales, along with a new five-year, 60,000-mile (97,000 km) engine warranty (these engines were christened the "Dura-Built 140"). It also benefited from greatly improved engine cooling. But the new-for-1976 Chevette, along with the Monza, began replacing the Vega with some product overlap. To use up existing, but slow-selling Vega parts, the 1977 model Pontiac Astre was equipped with the more reliable 2.5 L Iron Duke engine. Also, some 1978 Monza station wagons were built, using Vega sheet metal with Monza styled front ends.

The Vega was one of the first automobiles that GM produced that made extensive use of robotic welding equipment.

Cosworth Vega

The limited-edition 1975 to 1976 Cosworth Vega (see main picture) was a special performance version of the subcompact introduced long before cars like the Golf GTI or Mitsubishi Lancer Evolution. Only 2,062 were built the first year. It was fitted with a fuel-injected DOHC 2.0L 16-valve version of the engine designed by Cosworth Engineering in England, which was famous for its racing engines. This engine was known internally at Cosworth as Project EA. Built by Chevrolet at its Tonawanda engine plant, the engine was fed by Bendix electronic fuel injection controlled by a computer in the glove box. First planned in 1969, the first 1971 development engines delivered an impressive 180 bhp (130 kW). But when finally put into production, the 1975 engines produced only 120 bhp (89 kW). Chevrolet had originally planned to release the Cosworth Vega for the 1974 model year, but a burnt exhaust valve in a test engine caused the engine to fail the U.S. Environmental Protection Agency's 50,000-mile (80,000 km) emission control system durability test. This delayed the car's introduction until 1975.

The Cosworth Vega's exterior had special gold stripes and "COSWORTH TWIN CAM" lettering on the front fenders and rear cove panel. Interior changes included a gold engine-turned applique' on the instrument panel, a specific tachometer, and a plaque with the car's build sequence number. Also included were wide radial tires on gold-colored alloy wheels, anti-roll bars, and special exhaust with a dual-outlet tip. Air conditioning was not offered on the Cosworth Vega, due to interference between the induction system (specifically the air cleaner) and the air conditioner's evaporator case. At $5,916, it cost double a normal hatchback, and only $900 less than a Corvette. Car and Driver magazine would report "The 3.11 first gear matched to a 3.73 axle ratio makes the Cosworth Vega tough to launch from a stop". They measured 0-60 mph times of 8.7 seconds. In 2006 Inside Line wrote "Fat and strangled by emissions regulations and GM's own noise concerns, the Cosworth Vega was a disappointing car in every sense". This is decidedly misleading since all cars in 1975 and 1976 were similarly "fat and strangled by emissions regulations." Only 3,508 were sold over two years. This fell so short of projected sales of 5,000 that 1,500 unused exotic Cosworth engines were simply scrapped for lack of demand. Though sales would be disappointing, it is today the Vega most sought by collectors.


The Vega ultimately would be doomed by poor reliability and several highly publicized design problems including carburetor fires, engine overheating problems, and premature body rust, which began to affect sales after 1974 even though most of those problems had been resolved by that time. The aluminum engine block was grounded directly to the Vega's frame, accelerating body rust via Galvanic corrosion, eventually garnering it a reputation as "the car that began rusting on the showroom floor".[5]

Labor and management strife - including a three-week strike in early 1972 - also added to the car's woes. The Vegas were built at the GM Lordstown, Ohio plant, at a line whose line speed greatly exceeded that of older plants, and eventually Lordstown came to symbolize the worker discontent and worker alienation of the auto-industrial age.[6]

The Vega's engine, body corrosion, and other problems became well known. To dispel the Vega's sagging sales and reputation, Chevrolet made many internal improvements to the 140 cu in (2.3 L) four-cylinder engine for the 1976 model year, and backed this engine (now billed as the Dura-Built engine) with an unprecedented "5-year, 60,000-mile (97,000 km) warranty" at a time when most new cars and their drivelines were backed by one-year, 12,000-mile (19,000 km) warranties. By that time, the Vega's sales were sagging further due to new competition from two new small Chevrolet models, including the sportier Vega-derived Monza. The later Chevette was a world design adapted to the U.S. market. It would eventually replace the Vega as Chevy's entry-level import-fighter. The Chevettes also acquired a reputation for low quality. Chevrolet's first front wheel drive domestic compact, the Chevrolet Citation, debuted in 1979 and suffered from defects and recalls as well.

In a book (On A Clear Day You Can See General Motors) published by John DeLorean in 1979, who was president of Chevrolet at the time of development the Vega, he indicated that the prototype car literally fell apart just eight miles (13 km) into its first road test. DeLorean criticized the Vega as a poor design developed by central corporate GM engineers rather than Chevrolet engineers and said that the car had been forced upon a disgruntled Chevrolet by GM management. He also criticized the engine saying that it was "a relatively large, noisy, top-heavy combination of aluminum and iron which cost far too much to build, (and) looked like it had been taken off a 1920 farm tractor..." and "Chevy engineers were ashamed of the engine." [7]

All these well-publicized problems combined with a string of recalls hurt public perception and sales. Forbes Magazine included the Vega on its list of the worst cars of all time [8]. There are collector clubs for Vegas and derivative Monzas.


Vegas sold very well despite their problems, many of which were eventually corrected. In total, 2,154,434 Vegas and Astres were built from 1971 through 1977. A large majority of these were produced at the Lordstown Assembly plant, but Pontiac Astres were also built at Saint Therese Assembly in Quebec.

Year Vega Cosworth Astre Total Notes
1971 277,700 - - 277,700[9] All 1971 models known as "Vega 2300"
1972 394,592 - - 394,592 Glovebox added. Three-speed Turbo-Hydra-matic automatic transmission becomes new option and horsepower measurement changes from "gross" to "net" figures.
1973 395,792 - - 395,792 New front bumper and emissions equipment along with American-built three- and four-speed manual transmissions replacing the German Opel-built units of 1971-72 models. "2300" portion of name dropped with nameplates on front and rear now reading "Vega by Chevrolet". Pontiac Astre introduced for Canadian market.
1974 452,887 - - 452,887 New nose (similar to the one used on the 1974 Camaro), taillights and aluminum bumpers mounted on energy-absorbing springs. Powerglide transmission dropped from option list. "LX" option with vinyl roof and upgraded interior trim introduced for notchback coupe.
1975 204,178 2,062 64,601 270,841 First year for the U.S. version of the Pontiac Astre, and the Cosworth Vega; Chevrolet Monza introduced.
1976 159,077 1,446 50,384 210,907 Pontiac Sunbird and Chevrolet Chevette introduced. New grille and taillights. New cylinder head design with hydraulic valve lifters. Four-speed manual transmission now standard equipment on all models, and a new Borg-Warner five-speed manual transmission offered.
1977 78,402 - 32,788 111,190 Last year for Vega and Astre. Cosworth Vega discontinued. Astre gets new Pontiac-built 2.5 liter (151 cid) cast-iron block four-cylinder engine as standard equipment while Vega continues with 2.3-liter (140 cid) Dura-Built four.
Total 1,962,628 3,508 147,773 2,113,909

The Vega wagon body continued through 1978 and 1979 under the Monza nameplate. About 29,000 additional vehicles were sold under this name. The hatchback body continued briefly in 1978 as the "Monza S", presumably to use up surplus supply of 1977 bodies.


Because of the Vega's design, light weight, low cost, and poor durability of the stock four-cylinder engine, the car was a popular choice for performance modification. A small-block and big block Chevy V8 engine fit surprisingly well in the engine compartment; it was speculated at the time that GM had planned to offer a V8 Vega option -- the Vega-based Monza did so later with a first a 262 and then a 305 cubic inch small block V8. In modifying the Vega, the remainder of the drivetrain was also replaced typically with a Muncie 4 speed, a shortened V8 driveshaft, and a narrowed 12-bolt Chevy rearend. Heavy duty front coil springs were also required to support the increased engine weight, as well as a larger radiator for cooling. This conversion was so popular that parts and kits were readily available on the aftermarket from several manufacturers. For example, Don Hardy Race Cars of Floydada, TX and Doug Thorley sold many tube exhaust headers for the V8 conversion. The unit body of the Vega wasn't particularly strong, so high-performance conversions required modifications up to frame rails and full roll cages, for example.

One of the most famous Vega models used in drag racing appeared in 2005 when Speed Channel's Pinks featured a 1977 Vega wagon, known as the "Wooly Mammoth," in races which it won.

The hatchback on the Vega, for all years and models, is similar to the rear window plug used on 1969 Dodge Charger 500 and 1969 Dodge Charger Daytona. This has led to a large demand for hatchback doors for the cloning community.

See also


External links