Chevrolet Vega
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| Chevrolet Vega | |
|---|---|
| Chevrolet | |
| aka | Vega 2300 |
| Production | 1970-1977 1,966,157 including 3,507 Cosworth Vegas. |
| Class | Subcompact |
| Body Style | 2-Door Sedan 2-Door Hatchback 2-Door Wagon 2-Door Panel Delivery |
| Length | 169.7 in (4,310 mm) |
| Width | 65.4 in (1,661 mm) |
| Height | 51 in (1,295 mm) |
| Wheelbase | 97 in (2,464 mm) |
| Weight | 2181-2270 lb (1971) |
| Transmission | Rear Wheel Drive 3-Speed Manual 4-Speed Manual 5-Speed Manual O/D 2-Speed Automatic 3-Speed Automatic |
| Engine | 2.3 litre (140 CID) inline-4 2.0 litre (122 CID) inline-4 |
| Power | (2.3) 90 hp @ N/A rpm N/A lb-ft of torque @ N/A rpm (2.0) 110 hp @ N/A rpm N/A lb-ft of torque @ N/A rpm |
| Similar | Pontiac Astre |
| Designer | GM Design Team Chief Engineer, Ed Cole |
The Chevrolet Vega is a subcompact, four passenger automobile produced by the Chevrolet division of General Motors for the 1971–1977 model years. Designed from scratch by a GM corporate design team headed by Ed Cole, the car was brought to production by Chevrolet in only two years, offered in two-door body-styles: Notchback Sedan, Hatchback Coupe, Kammback Wagon, and Panel Express. The Vega engine is an aluminum-block 140 cubic inch (2.3 liter) inline-4. By 1974, the Vega was among the top 10 best selling American cars reaching its model-year sales peak of over 450,000. Its GM H platform expanded in 1975, with the Vega-based Monza and variants for three other GM divisions. With just 78,000 produced in its final year, Chevrolet trimmed the car and its aluminum engine from the lineup after the 1977 model run. The Monza and varients continued through 1980.
See Wikicars' comprehensive 'Chevrolet Vega Review
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History
Origin
In 1968 GM chairman James Roche announced that General Motors would bring out a new mini-car in two years. Vega's chief engineer Ed Cole wanted a world-beater, and he wanted it in showrooms in 24 months. This was an extremely short time to design and engineer a new car, especially one that borrowed almost nothing from any other. The Vega, like the Corvair, has long been referred to as Ed Cole's baby. Cole formed a GM corporate design team exclusively for the Vega headed by William Munser, who had worked on the Camaro and the Turbo-Hydramatic transmission . It was as GM president that Cole oversaw the genesis of the Chevrolet Vega. Code-named XP-887, Chevrolet "teaser" ads began in May 1970, not announcing its name at first, stating-"you'll see."
Design & Engineering
GM purpose-built an advanced $75 million plant, Lordstown Assembly in Lordstown, Ohio to produce the Vega where 90 percent of the necessary welding was performed by high-tech unimate robots. Due to its "Modular Construction Design", a Vega sedan with 578 body parts had 418 fewer parts than its full-size Chevrolet counterpart. Modular Construction Design reduced the number of joints and sealing operations resulting in stronger, tighter bodies, effectively contributed to vehicle quality and made possible a very high rate of production. Vega production at Lordstown was projected at 100 cars an hour from the beginning: one vehicle every 36 seconds. This was nearly twice the normal volume and by far was the fastest rate in the world.
The engine and its die-cast block technology were developed at GM Engineering Staff, long before the program was handed-off to Chevrolet to finish and bring it to production. Ed Cole, who had been very personally involved with the design of the 1955 Chevrolet V8 as Chief Engineer at Chevrolet, was equally involved with the Vega engine as GM president, and was a frequent visitor on Saturdays to the Engineering Staff Engine Drafting Room, reviewing the design and giving direction for changes. As the engine development progressed at Chevrolet, it became known (in closed offices) as “The World’s Tallest, Smallest Engine” due to the very tall cylinder head.
Opel was commissioned to tool up a new 3-speed derivative of their production 4-speed manual transmission . Opel did just that, and tooled up a new 3-speed from scratch, just for the Vega application, whose actual cost was higher than the (optional) Opel 4-speed due to the tooling investment and low production volume. Both transmissions came by ship from Germany 100 transmissions to a crate, and arrived in shipments of thousands of transmissions at a time.
The overall chassis suspension was to be tuned to a new A78 x 13 tire that was being developed concurrently with the vehicle. The front suspension is classic General Motors short-and long-arm. The lower control arm bushings were actually larger than those of the Camaro. The four-link rear suspension copied that of the Chevelle, and coil springs are used throughout. This was a significant departure from the leaf spring suspension used in the Camaro and Nova. The Vega's brake system copied an excellent Opel design including solid rotors and a lack of a proportioning valve.
The body surface was the first accomplished completely through use of computers. Body surface information recorded on tape derived from the clay styling model, allowed computers to improve the body surface mathematically. Tapes developed through the computer were also used to control drafting machines in producing master surface plates which were extremely accurate. The computer was also utilized in making the hundreds of necessary engineering calculations including vision angle, field of view, rear compartment lid and door counterbalance geometries, structural stresses, deflection calculations and tolerance studies. All Vega models share the same hood, fenders, floor pan, door lower panels, rocker panel, engine compartment, and front end. In a size comparison with a 1970 Nova, the Vega has 20 inches less overall length, 14 inches less wheelbase, 7 inches narrower width and 2 inches lower height.
The Vega was one of the first Chevrolet vehicles to have as standard equipment front disc brakes, an electric fuel pump, side guard door beams, a double paneled roof, and foam-filled, hi-back bucket seats with floor mounted controls.
Development History 1968-1975
The Chevy Vega was conceived in 1968 as a simple, low-cost transportation vehicle to utilize the newly-developed all-aluminum die-cast engine block technology. In October of 1968, there was only one body style (the “11” style notchback coupe), one engine, one transmission (the MB1 Torque-Drive manually-shifted 2-speed automatic), no headliner, one base trim level, a bench seat, molded rubber floor covering, no glove box, no air-conditioning option, ventilation only through the upper dash direct from the wiper plenum, and exterior paint on the interior. As the program progressed into development, the market changed, and so did the product:
December, 1968 – Hatchback, station wagon, and panel delivery styles added. Kickpad floor-level ventilation added. Optional performance engine (“L-11” 2-barrel) added; predicted at 20%, actually ran at 75%. Bucket seats replaced bench seat as standard equipment. Carpeting and headliners added for hatchback and station wagon. Air-conditioning option added; predicted at 10%, actually ran at 45%.
February, 1969 – Opel three- and four-speed transmissions added (3-speed standard, others optional), Powerglide added (now four transmissions), mechanical fuel pump replaced by in-tank electric pump, power steering option added, base “11” style notchback trim upgraded to match hatchback and wagon (carpet and headliner).
April, 1969 – Gauge-pack cluster option added, HD suspension and wide tire option added (ran at 40%), adjustable seat back option added (ran at 45%), bumpers restyled, lower valance panels added, swing-out quarter window option added (ran at 10%).
July, 1969 – Electrically-heated backlite option added (ran at 10%), “GT” package option added at $325.00 (ran at 35%), bright window-frame and roof drip moldings added to hatchback and wagon (instead of painted).
September, 1969 – Interior trim color painting now standard (previously only part of Deluxe Interior and “GT” – others were to get exterior color inside), D-88 Side Paint Stripe added (ran at 15%), “Mag-Style” steel wheels added to “GT” option, lower valance panels restyled again with big round front lamps and painted body color. Plastic front fender liners cancelled due to $2.28 cost per car.
This is essentially how the car launched as a 1971 model on June 26, 1970. After the National GM strike (9/70-11/70) ended, bright roof drip moldings were added to the base “11” style notchback; moldings were sent to dealers to update units already in the field in December. The car still had no glove box.
August, 1971 – 1972 model launched; glove box added, cloth custom trim option added, 3-speed automatic added (now five transmissions).
October, 1971 – Fisher Body and Chevrolet plants combined under GM Assembly Division management; major production losses through March, 1972 due to work stoppages, slowdowns, sabotage, and the politics of local union consolidation into one local. Much negative national publicity (“60 Minutes”, “20-20”, “blue-collar blues”, etc.), supervisors shot at and run off the road on the way home from work, company cars “keyed”, bashed, and flipped over leaving the plant gate by hooded pickets.
March 6-27, 1972 – Local strike over GMAD efficiency improvements, settled with no changes – effort begun to improve relations with local union. Production resumes with normal attainment of 100 per hour (1600/day).
August, 1972 – 1973 model launched.
September, 1972 – Vega production begins at Ste. Therese, Quebec, on one shift at 35 per hour (280/day); total Vega production now 1880/day.
January, 1973 – Wood-grain station wagon option introduced (ran at 8%).
March, 1973 – Deluxe “11” style option introduced – vinyl top, etc. (ran at 3%), Station wagon roof luggage rack added.
April, 1973 – First Cosworth Pilot Program conducted at Ste. Therese, Quebec Assembly Plant (Lordstown Assembly not operating due to adjacent Fisher Body Stamping Plant strike); seven silver cars built for Engineering.
May, 1973 – Ste. Therese adds a second shift to increase plant output to 480/day; total Vega production now 2080/day. “Millionth Vega” option added at $500, 6500 built at 10 per hour from 5/1 to 7/1. “Spring Stripe” package added.
August, 1973 – major change for 1974 model – new underbody welding system, major body structure changes for new bumpers, new front and rear end styling.
December, 1973 – Ste. Therese increases volume from 35 to 50 per hour for plant output of 800 per day; total Vega production now 2400/day.
January, 1974 – Plastic front fender liners added (after replacing thousands of sets of rusted-out fenders under warranty on 1971-74 models).
February, 1974 – “Spirit of America” package (white trim, vinyl top, side stripes, etc.) added – 7500 built through May.
April, 1974 – Cosworth emission certification car burns exhaust valves at 46,000 miles of 50,000-mile test; program delayed to 1975 model year – was to have launched in May, 1974.
August, 1974 – major 1975 model change – Pontiac Astre added, third luxury trim level added; “rolling model change” at 100 per hour with no downtime or lost units (GM’s first).
February, 1975 – Five Cosworth Pilot units built during the first week, both Cosworth emission certification cars successfully complete 50,000-mile test at the end of the same week.
March, 1975 – EPA indicates Certificate will be issued on the 25th, first salable production Cosworth is built on the 27th.
April 17, 1975 – Lordstown Media Event for Cosworth production launch.
- Development & Production History 1968-1975 written by John Hinckley GMAD-Lordstown Vega Launch Coordinator 1969-1975.
Body Styles and Major Options
The Hatchback was the most popular model with its lower roofline and useful hatchback with fold-down rear seat, and accounted for nearly half of Vega's total production. The Sedan, renamed Notchback in 1973, was the lowest priced Vega at $2090. It has more rear seat head room than the Hatchback and is the only Vega model with an enclosed trunk.
The Kammback Wagon has more cargo capacity, a fold-down rear seat, a swing-up liftgate, and retains Vega's handling capabilities. The Panel Express, a one passenger panel delivery based on the wagon body has steel panels in place of the rear side glass, and an additional enclosed storage area replacing the rear seat.
In mid-1971 a GT version for Hatchback and Kammback models was introduced. The GT package included the L11 2 barrel carburetor engine, F41 handling suspension, 6-inch wide GT wheels with trim rings and center caps, A70-13 raised white-letter tires, black-finished grill and lower body sills, clear parking lamp lenses, full instrumentation, adjustable driver's seat, passenger assist handle, and a hood/deck sport stripe option.
In 1973, new Notchback and Kammback packages were introduced. The LX Notchback included a vinyl top, custom exterior and interior. It was offered through 1975, replaced by the Cabriolet Notchback, featuring a half vinyl top and opera styled rear side windows similar to the Monza Towne Coupe. The Kammback Estate wagon featured wood-grained vinyl side trim with outline moldings and the custom interior.
Limited Editions
Yenko Chevrolet sold a specially modified Vega called the Yenko Stinger II through 1973. Based on the GT, its 140 CID L11 engine featured a turbocharger, high compression pistons and was rated 155 hp. Included were front and rear spoilers and side striping with "Yenko Stinger II" identification.
Special limited edition Millionth Vega
On May 17, 1973 the millionth Vega was produced at the Lordstown, Ohio assembly plant-a bright orange GT Hatchback with white sport stripes and Millionth Vega door handle accents. It featured power steering and a neutral custom vinyl interior with orange accent color carpeting. A special limited edition Millionth Vega replicated the milestone car. 6500 were produced.
The 1974 Vega Spirit of America Hatchback limited edition featured a white exterior, white vinyl roof, blue and red striping on body-sides, hood and rear-end panel, Spirit of America I.D. on front fenders and rear panel, white "GT" wheels, trim rings and Chevy center caps with A70-13 raised white-letter tires, and a white custom vinyl interior with red accent color carpeting. 7800 were produced.
In March, 1975 the Cosworth Twin-Cam Vega was introduced after a year and a half delay. Chevrolet's single color ad stated, "Cosworth Twin Cam-one Vega for the price of two." The engine was an all-aluminum 122 cubic inch (2.0L) double overhead cam DOHC 16-valve inline-4 with stainless steel headers and Bendix electronic fuel injection. Power output - 110 bhp. All 1975 Cosworth Vegas were black w/gold accent stripping, gold-colored aluminum wheels and a black custom vinyl, black custom cloth, or white custom vinyl interior with a gold "engine turned" dash bezel and gold plated plaque with Cosworth ID and build number. In 1976, eight additional exterior, and two additional interior colors were offered. 5000 units per year were intially projected. Only 3,508 were produced through 1976. 1500 Cosworth Vega engines were scrapped for lack of demand.
Production & Changes
1,966,157 Chevrolet Vegas were produced from 1970 through 1977, including 3,507 Cosworth Vegas. The majority were built in the United States at the GM Lordstown Assembly plant in Lordstown, Ohio. Starting In 1973 through 1974, Vegas were also built at the GM of Canada plant Saint Therese Assembly in Quebec.
1971 Production - 277,700
1972 models were essentially carried over from the first 1971 models with a few refinements including revised rear shocks. Vibration and noise levels were reduced with a redesigned exhaust and better driveline damping. A glove box was added and replaced dash storage bin. 1972 Production - 395,592
The 1973 Vega had over 300 changes including new colors and new standard interior trim. Vega's front bumper was extended three inches on stronger brackets with a steel color keyed filler panel to meet the 1973 5-mph front bumper standards. Two new models were introduced- The LX Notchback included a vinyl roof and the Estate (Woody) Kammback featured vinyl wood side trim. Both models include the custom exterior and interior options. New Saginaw manual transmissions replaced the imported Opel designed units and the Turbo-hydramatic transmission replaced the Powerglide. 1973 Production - 395,792
The 1974 model year brought the only major exterior design changes, due to the revised, Federal front and rear 5 mph bumper standards-A slanted header panel with a steel louvered grill (replacing the plastic egg-crate grill) and recessed headlamp bezels complement the larger, front 5 mph aluminum bumper. Front and rear license plate brackets were relocated and a larger rear 5 mph aluminum bumper was used. A revised rear panel on Notchback and Hatchback had larger single unit tailights and ventilation extractor grills were eliminated on trunk and hatch lids. Due to the 5 mph bumpers, overall length was increased six inches compared to the 1971-1972 models. 1974 Production - 452,886
The 1975 Vega had 264 changes including High-energy Electronic ignition and Catalytic converter. Power brakes and Tilt steering wheel were new options. A new special custom cloth interior option was offered with interior trim and carpeting upgrades similar to the Monza 2+2. The Cosworth Vega was introduced in March. The Vega Panel Express was discontinued at the end of the 1975 model year. Never a big seller, Panel sales peaked in the Vega's first year, in 1971 at 7,800 units. After leveling off to an average of 4,000 units per year, only 1,525 1975 Panels were sold. 1975 Production - 206,239 (includes 2061 Cosworth Vegas)
1976 Vegas were refined with extensive engine, chassis, and body integrity improvements. Chevrolet advertised the 1976 Vega as "Built to take it." A facelift included a revised header panel, wider grill, revised headlamp bezels-all made of corrosion resistant material-and tri-color tailights for Notchback and Hatchback. The 2.3L engine, named Dura-built 140, received improved cooling and durability refinements. The chassis was now the same as the Monza including a box section front crossmember, larger rear brakes and torque-arm rear suspension, replacing the four-link design, effectively eliminating wheel-hop on rough roads. The body received extensive anti-rust improvements. New models introduced were the GT Estate wagon and Cabriolet package for the Notchback, replacing the LX. It featured a half vinyl roof and opera windows similar to the Monza Towne Coupe. The Cosworth Vega was quietly discontinued. 1976 Production - 160,523 (includes 1442 Cosworth Vegas)
1977 was the final year for the Vega, carried over from 1976 with a few revisions and additions. The Notchback was re-named Coupe. Vega's Dura-built 140 engine received a pulse-air system to meet the more strict 1977 Federal emission standards. A full console was a new option, and the GT received blacked-out trim and a revised side stripping option. 1977 Production - 78,402
Vert-a-pac
The Vega was designed to be shipped vertically, nose down. Special rail cars known as Vert-A-Pac cars held 30 Vegas versus 18 in normal tri-level autoracks. Each Vega was fitted with four removable, cast-steel sockets inserted into the undercarriage.
Chevrolet conducted vibration and low-speed crash tests to make sure nose-down Vegas wouldn't shift or be damaged in railcar collisions. Chevrolet's goal was to deliver Vegas topped with fluids and ready to drive to the dealership. To do this Vega engineers had to design a special engine oil baffle to prevent oil from entering the No. 1 cylinder, batteries had filler caps located high up on the rear edge of the case to prevent acid spilling, the carburetor float bowl had a special tube that drained gasoline into the vapor canister during shipment, and the windshield washer bottle stood at a 45 degree angle. Plastic spacers were wedged in beside the powertrain to prevent damage to engine and transmission mounts. The wedges were removed when cars were unloaded.
Engine
Sports Car Graphic magazine said in August 1970: "The new die cast aluminum Vega 2300 (engine) is a masterpiece of simplicity. There are many innovations made to reduce the number of pieces and improve repairabilaty. One belt drives cam and water pump. The movable water pump is also the belt tensioner. The oil pump is on the crankshaft and is also the front engine cover."
Collectible Automobile magazine said in April 2000, 30 years later: "The Vega engine was, without a doubt, the most extraordinary part of the car."
140 CID OHC
The Vega engine is a 140 cubic inch (2.3 liter) inline-4 featuring a die-cast aluminum cylinder and case assembly and a cast-iron cylinder head with a single overhead camshaft (SOHC). The cylinder block is an open deck design with siamesed free-standing cylinder bores. Outer case walls form the water jacket and are sealed off by the head and the head gasket. The block has cast iron main caps and a cast iron crankshaft. The cast iron cylinder head was chosen for low cost and structural integrity. The overhead valvetrain is a direct acting design of extreme simplicity. Only three components activate the valve rather than the usual seven of a typical push rod system. The camshaft is supported by five conventional pressed-in bearings. The camshaft is driven from the crankshaft by an externally mounted continuous cogged belt and sprocket system. Six v-grooves on the outside of the belt drive the water pump and fan. The large bore and long stroke design provide good torque and lower rpm operation for reduced wear. Compression ratio for the standard and optional engine is 8.5:1 as engine was designed to operate on low-lead and no-lead fuels. A single-barrel carburetor version produced 90 gross hp. The two-barrel version (RPO L11) 110 gross hp. From 1972 on, rating was listed as net hp. The one-barrel engine produced 80 hp. The two-barrel option boosted output to 90 hp. The 1972 Rochester 2bbl carburetor required an air pump for emission certification and was replaced in 1973 with a Holley-built 5210C staged 2bbl carburetor. Emission control revisions made in 1973 reduced power output by 3 hp, although the engine's cruising noise levels were reduced. High energy electronic ignition and catalytic converter were additions for 1975. The 1976 2.3 engine, named "Dura-built 140", featured improved coolant pathways for the aluminum-block, a redesigned cylinder head incorporating hydraulic valve lifters, longer life valve stem seals which reduced oil consumption by 50%, a redesigned water pump, head gasket, and thermostat. With a 5 year/60,000 mile engine warranty, the 1976-77 Vega was marketed as a durable and reliable car. The 1977 Dura-built 140 engine, added a pulse-air emission control system adopted from the Cosworth engine, needed to meet the more strict for 1977, US Environmental Protection Agency (EPA) emission standards.
The Chevy Monza's standard engine was the 140 inline-4 its first year in 1975, and the Dura-Built 140 for 1976-77. The Pontiac Astre used 140 engine for 1973-74 (Canadian), 1975, and the Dura-Built 140 engine in 1976 only, in both the Astre and Sunbird. Oldsmobile's first four-cylinder offering was the Dura-built 140, standard in the 1977 Olds Starfire.
Aluminum Engine Block
GM Research Labs had been working on a sleeveless aluminum block since the late 50's. The incentive was cost. Getting rid of those liners on a four-cylinder block would save $8 per unit, which was a substantial amount of money back then. Reynolds Metal Corp. came up with an alloy called A-390, composed of 77 percent aluminum, 17 percent silicon, 4 percent copper, 1 percent iron, and traces of phosphorus, zinc, manganese, and titanium. The A-390 alloy was suitable for faster production diecasting which made the Vega block less expensive to manufacture than other aluminum engines. Sealed Power Corp. developed special chrome-plated piston rings for the engine that were blunted to prevent scuffing. Basic work had been done under Eudell Jackobson of GM engineering, not at Chevrolet. But then, suddenly, Chevrolet got handed the job of putting this ohc sleeveless, aluminum block into production-a feat never before attempted. According to Jackobson, "The aluminum blocks were inpregnated with sodium silicate before shipping to Tonawanda (engine plant). Machining through the outer skin exposed areas that had not previously leaked, so various leak tests were required as the block progressed through the machining line. As I recall, if a part still leaked after three tries, it was scrapped."
The Vega engine block was cast in Massena, New York, at the same factory that produced the Corvair engine. Molten aluminum was transported from Reynolds and Alcoa smelting plants to the foundry, inside thermos tank trucks. The block was cast using the Accurad process. The casting process provided a uniform distribution of fine primary silicon particles approximately 0.001 inches in size. Pure silicon provides a hard scuff and wear resistant surface, having a rating of 7 on the mohs scale of hardness as compared to diamond which is 10. The blocks were aged 8 hours at 450 °F to achieve dimensional stability. The technical breakthroughs of the block lay in the precision die-casting method used to produce it, and in the silicon alloying which provide a compatible bore surface without liners.
From Massena, the cast engine blocks were shipped as raw castings to Chevy's engine plant in Tonawanda, New York. Here they underwent the messy etch and machining operations. The cylinder bores were rough and finished honed conventionally to a 7 micro-inch finish then etched by an electro-chemical process. The etching removed approximately 0.00015-inch of aluminum leaving the pure silicon particles prominent to form the bore surface. At a machined weight of 36 pounds, this block is 51 pounds less than the cast-iron block in the Chevy II 153 CID inline-4. Plating the piston skirts was necessary to put a hard iron skirt surface opposite the silicon of the block to prevent scuffing. The plating was a four layer electo-plating process. The first plate was a flash of zinc followed by a very thin flash of copper. The third and primary coating was hard iron, 0.0007 in thick. The final layer was a flash of tin. The zinc and copper were necessary to adhere the iron while the tin prevented corrosion before assembly of the piston into the engine. Piston plating was done on a 46 operation automatic line. From Tonawanda, the engines went to the Chevrolet assembly plant in Lordstown, Ohio.
Cosworth Twin-Cam
The 1975-76 Cosworth Twin-Cam is a limited production, performance version of the Vega. Its purpose was to "create excitement" for the entire Vega line. Only 3,508 were built from March 1975 through 1976.
Development
The racing version was known internally at Cosworth as Project EA. It was not a successful racing engine due to engine block structural failures. Chevrolet later offered a special heavy-duty block with thicker case walls for racing applications, but by that time Cosworth had moved on.
The Vega production version was developed and built by Chevrolet at its Tonawanda engine plant. The first 1971 development engines delivered an impressive 180 bhp (130 kW). Chevrolet had originally planned to introduce the car 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 emission control system durability test. This delayed the car's introduction a year and a half while Chevrolet revised the Cosworth engine's emission control system, adding the pulse-air tubes, and revised its Bendix Electronic fuel injection and timing specs. It passed the EPA test the second time, and the Cosworth Vega was introduced in March, 1975. Final rating is 110 bhp.
122 CID DOHC
The Cosworth Vega engine is a 122 cubic inch (2.0 liter) inline-4 and features a die cast aluminum cylinder and case assembly and an aluminum, 16 valve cylinder head with double overhead camshafts (DOHC). The head design was assisted by Cosworth Engineering in England. The camshafts are held in a removable cam-carrier which also serves as a guide for the valve lifters. Each camshaft is supported by five bearings and is turned by individual cam gears on the front end. The two overhead camshafts are driven, along with the water pump and fan, by a fiberglass cord reinforced neoprene rubber belt, much like the Vega 140 (2.3 liter) L-4 engine. Below the cam carrier is a 16 valve cylinder head constructed of an aluminum alloy and using sintered iron valve seats and iron cast valve guides for added durability. Forged aluminum pistons are used because of their added strength, and results in improved durability under severe operating conditions. The engine features an electronic fuel injection system, and a stainless steel exhaust header. Each engine was hand-built and includes a cam cover sticker with the engine builder's signature. The engine develops its maximum power at 5,600 rpm and is redlined at 6,500, where the SOHC Vega engine peaks at 4,400, and all is done at 5,000.[49] Car and Driver reported, "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 (97 km/h) times of 8.7 seconds. [50]
Features
Chevrolet general manager, John DeLorean chose black over Cosworth silver, the original choice, as the car's exclusive color. 1974 pre-production cars released to the press, and all 2,062 1975 Cosworth Vegas were indeed, black with gold "Cosworth Twin Cam" lettering on the front fenders and rear cove panel and gold pinstriping on hood bulge, body sides, wheel openings, and rear cove. Black exterior color wasn't available on lesser Vegas until the following year. The black or white custom vinyl, or black custom cloth interior, includes a gold engine-turned dash bezel and gold-plated dash plaque with build sequence number, a specific 8000 RPM tachometer and Cosworth Twin-Cam Vega steering wheel emblem. At $5,916, it cost double a normal hatchback, and only $900 less than a Corvette. The Cosworth package includes a 'torque arm' rear suspension which provides optimum rear axle power control. This unit compares to the assembly used on the Monza 2+2. The Monza 2+2 axle is also used and provides a 3.73:1 gear ratio from a 7-1/2" ring gear. No other gear ratios were available, but a limited slip differential was optional. GT special springs, shocks, and stabilizer bars are included as are exclusive BR70-13 BSW radial tires on British-made 6 inch, gold-painted cast aluminum wheels with Chevy center caps. The Vega engine overheat protection system is used on the Cosworth package. This adds add coolant and temp/press warning lights to the instrument cluster. If the radiator coolant level becomes one quart or more low, a sensor, located in the radiator, activates the add coolant light. If the coolant temperature reaches 260 °F or greater or if the engine oil pressure drops below 6 psi, then the temp/press light is activated. 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. Power steering and power brakes were also not offered.
1976 Changes
For 1976, the Cosworth, like all Vegas, received a facelift including a wider grill and tri-color tail lamps and the extensive body anti-rust improvements. A new Borg-Warner 5-speed manual overdrive transmission with 4.10 axle was optional in addition to the std. Saginaw 4-speed manual. The exhaust system featured a single outlet tailpipe as opposed to the dual outlet pipe on the '75. Eight additional exterior colors were offered in addition to black and two additional interior colors were offered. Still, only 1,446 were built for 1976. The Cosworth Vega, although meeting the more strict 1977 emission standards in advance, would not be offered in the Vega's final year. Production fell well short of projected sales of 5,000 per year, which was figured before the Vega's early model troubles became well known. Introduced a year earlier in 1974, as planned, the car might have met its sales goal. As it stood though, 1,500 unused Cosworth engines were simply scrapped for lack of demand.
Performance
Motor Trend in its August 1970 issue said: "In summary, the Vega GT comes close to what a racing GT car should be, in handling, performance and comfort. Because it's basically a low-priced compact, the results are all the more surprising and rewarding."
Road & Track in their 1970 road test of "Vegas Plain and Fancy" said: "The engine proved a let down. It's extremely rough and noisy..on the positive side, freeway cruising is relaxed and quiet, the slow-running engine's noise covered by wind and road noise, and it was economical not withstanding our overall mileage figures which include some very hard driving." "Ride and handling were departments in which we also expected good things and here we weren't disappointed. The Vega in standard form rides and handles very well indeed."
Car and Driver in January 1971 gave the Vega top rating in their small-car comparison test with the Ford Pinto, AMC Gremlin, VW Beetle, Toyota Corolla and Chrysler Simca "because of Vega's particular suitability to American driving conditions." It was the only car besides the shortened compact Gremlin that could cruise at 70 miles per hour or above. Its long 2.53:1 axle ratio allowed a low 3,000 rpm at 80 mph. The Vega's ride and handling were highly rated. It was the quickest of the cars tested, taking 12.2 seconds to reach 60 mph. C&D stated: "It provides an excellent combination of performance and economy."
Road & Track in a Vega GT road test, began: "The 1973 Vega is still the stylish, somewhat sporting economy car it was when new, but improved. The Vega's engine is much improved, with cruising speed noise levels lower than most economy cars." Closing the test article, R&T stated: "After what we've said about earlier Vegas, it's a pleasure to report the current Vega is attractive, respectably quick, and frugal-and it's the best highway car in class. Well done Chevrolet."
Road Test magazine, in a July 1974 Test report on a Vega LX Notchback said: "Vega engineers have tamed the low-speed characteristics of the engine. It's wonderfully torquey and flexible at drive-away speeds, and you can shift early into fourth and chug around town all day if you like...in normal driving low and mid-range torque is what counts and this engine has plenty of it." "The Vega ride is not like that of a Caprice, but neither is it a choppy "little-car" ride thanks to the big car rear suspension (coil springs and control arms), ample suspension travel and reasonably good damping..." "The standard manual steering is on the heavy side and is too slow to permit fancy maneuvering..." "Braking performance is right in there too, which is credited to the brakes themselves and the big (radial) tires." "In summary, the 1974 Vega is a vastly improved car over the original and even over last year's model. All of the important gripes have been taken care of and it can now face up to its competition, domestic and imported, on a feature for feature basis.
Road & Track, in a March 1976 Cosworth Vega road test noted: "The reduction in displacement adds an important degree of smoothness..." a result of the shorter stroke. "We can't resist saying that with the Cosworth Vega engine, the Vega now runs the way it should have run all the time-easy, smooth, good response, good handling: a nice balance between performance and economy."; "For all its exotic features, however, the Cosworth Vega engine is not a high performance unit with a specfic output of only 55 bhp per liter, modest indeed when compared to engines of equal sophistication." "The Cosworth Vega's handling is very good..."; "All our drivers agreed that it is a far better handling car than those Vega derivatives that have been fitted out with V6 or V8 engines."
Unique Attributes
High tech assembly
At the Lordstown Assemby plant 90 percent of the welding was performed by high-tech unimate robots. The car's Modular Construction contributed to vehicle quality resulting in stronger, tighter bodies. The body surface was the first accomplished completely through use of computers. Body surface information from the clay styling model, allowed computers to improve the body surface. Tapes developed through computers were also used to control engineering drafting machines in producing accurate master surface plates.
Handling
The suspension and live rear axle design, near ideal weight distribution, low center of gravity and neutral steering gave the Vega world-class handling characteristics that were praised by the automotive press. The car's handling was top rated to its competition foreign and domestic.
Road & Track stated in September 1970: "Vega is the best handling car ever sold in America."
Styling
The Vega's styling was judged conservative, clean-lined and timeless. The GM styling studio's main influence was the 1967-1969 Fiat 124 Sport Coupe AC. The Chevrolet Camaro/Corvette studio completed the design and grafted a 1970 Camaro-like grill, and Chevy-style dual tailights.
Road & Track in November 1970 test - Vegas plain and fancy, said: "The plain Vega sedan is as good-looking a car as you'll find in its class...with the Vega they've turned out one of the finest-looking compact sedans in the world."
Car and Driver in December 1971 Super Coupes test including the Vega GT, Pinto Runabout, Opel 1900 Rallye, Mazda RX-2, Capri 2000 and Toyota Celica said: "..If looks alone determined the best Super coupe, the Vega GT would win hands down without ever turning a wheel."
Owner friendly
Many service operations were intentionally designed so that they were able to be performed by Vega owners. To further that end, the "Do-It-Yourself" service manual was made available with each new Vega.
Awards
Motor Trend included the Vega as one of the Ten Best Cars of 1971.
Motor Trend chose the Vega as Car of the Year for 1971 stating: "We choose the Vega as the Car of the Year because of Vega's engineering excellence, timeliness, styling, and overall value...for the money, no other American car can deliver more."
Motor Trend selected the Vega GT 1973 Car of the Year in the economy class stating, "The Vega was judged solid, warm and comfortable, with a good finish."
Car and Driver Reader's Choice Poll voted the Vega Best Economy Sedan three years in a row (1971-1973) In 1971, Vega's first year on the market, it managed to unseat the incumbent import, breaking its eight year winning streak.
Car and Driver included the 1974 Cosworth Vega as one the Top 25 Acceleration Champs stating: "Each year one car emerges as the winner. The Cosworth Vega was the quickest 0-60 mph car of 1974."
Car and Driver included the Cosworth Vega as one of the 10 Best Collectable Cars in its fourth annual "Ten Best" issue stating, "We're talking about historical significance here."
Reliability
New York International Auto Show 1976
The Vega's reliability within the Chevrolet line was second only to the Nova but early engine troubles hurt the car's durability record.
"August 1, 1975. 8 a.m. Outside the southern edge of Las Vegas. Three medium orange Vegas start their engines. They won't be turning them off much during the next 58 days except for rest and food stops, refueling and maintenance. They have a job to do."
Chevrolet conducted an advertized 60,000 miles in 60 days Durability Run of the 1976 Vega and its Dura-built 140 engine. Three new Vega hatchback coupes equipped with manual transmissions and air conditioning were driven non-stop for 60,000 miles in 60 days through a Nevada Death Valley test loop with air temperatures seldom under 100 degrees. Fuel stops and oil changes were supervised by the US Auto Club. All three 1976 Vegas completed a total of 180,000 miles with no failures. (One car needed a timing belt replacement and twenty four ounces of coolant)
Criticisms
GMAD-Fisher Body
In October 1971, General Motors ordered Chevrolet and Fisher Body to turn over Lordstown to the General Motors Assembly Division (GMAD) One of its missions was to cut costs. GMAD ran a much tighter ship and discipline became more rigorous. The United Auto Workers (UAW) claimed that 800 workers were laid off at Lordstown within the first year of GMAD's arrival and the line speed didn't slow. Feelings got worse with management accusing workers of intentionally slowing the line and sabotaging cars by leaving parts off and doing shoddy work. Quality did suffer, and in March 1972, the plant's 7,700 workers called a wildcat strike that lasted a month and cost GM 150 million dollars.
Fisher Body was very proud of its Elpo primering process, which should have prevented rust, but didn't. The Elpo process involved submerging the assembled Vega body in a huge vat. The Elpo vats at Lordstown each contained reddish-brown paint-primer particles in 65,000 gallons of water. In the Elpo dip, the metal body received a positive electrical charge, the primer particles carried a negative charge, and by leaving the body in the vat for two minutes even the most remote recesses get coated-theoretically. The body was then dried, sprayed with acrylic lacquer and baked in a 300 degree oven. The Elpo dip, however, did not flow to every surface. According to Vega expert, Gary Derian, the design of the front end caused air to be trapped at the tops of the fenders, so they never got coated Early cars had no inner fenders or fender liners, so the tops of the front fenders got blasted by sand and salt thrown up by the tires, and they quickly rusted. Chevrolet installed plastic deflectors in late 1973, and full plastic inner fenders in 1974. A rust-prone gap existed between the front fenders and the cowl vent. Moist debris and salt would pack into this area, and rust through the metal in a couple of years. Chevrolet did replace rusted-out fenders for many owners free of charge. But rust damage also affected the rocker panels, the door bottoms, the area beneath the windshield, and the primary body structure above the rockers. Starting in 1976, Chevrolet began spraying the inner doors with an aluminized wax, and making front fenders and rocker panels out of galvanized Zincrometal.
Early 140 CID Engine
L11 engine option with Rochester 2bbl. carburator
GM engineer Eudell "Jake" Jacobson confirmed a problem involving the early two-barrel Rochester carburetor. "...the Vega engine sometimes shook to the extent that it would loosen the screws that bolted the top cover to the carburetor body. The top cover would then jump up and down, which activated the accelerator pump, which shot raw gasoline through the cylinders and into the exhaust system. Fuel would puddle inside the muffler and eventually explode; backfire. The early mufflers would blow out towards the fuel tank, so later ones were engineered so they'd blow away from the tank. We also started using Loc-Tite on the carburetor bolts." Starting in 1973, the Rochester carb was replaced with a Holly-Weber design.
Jackobsen continued: "After the engine had been in production for a while, customers would go back to the dealer complaining about oil consumption... The mechanic would peer down the bore scope and see a little scuffing. We eventually found out that the problem had never been the scuffing of the (cylinder) bore. The real problem was the valve stem seals. They'd harden, split, fall off, and oil would leak down past the valves and into the combustion chamber. We did some experiments. When we got an oil burner, we simply replaced the valve-stem seals, and that cured it." 1976-77 Dura-built engines had redesigned seals that reduced oil consumption by fifty percent.
The Vega's cooling system came in for criticism. Although it held only 6 quarts and had a tiny two-tube 1 foot square radiator, when topped off, the Vega cooling system was adequate. But most owners tended not to check the coolant level often enough, and in combination with leaking valve-stem seals, the engine would often be low on oil and coolant simultaneously. This caused overheating, which distorted the open deck block, allowing antifreeze to seep past the head gasket, causing piston scuffing inside the cylinders. GM engineer Fred Kneisler stated: "Too much emphasis had been put on overheating problems versus the real culprits: brittle valve stem seals and too-thin piston plating." In response, Chevrolet added a coolant overflow bottle and an electronic low-coolant indicator in 1974 that could be retrofitted to earlier models at no cost. Regardless of the cause, damaged cylinder walls were common. Under a revised 50,000 mile engine warranty for 1971-1975 Vegas, owners had a choice to have the short block replaced with a brand new unit or a rebuilt steel-sleeved unit. This proved costly for Chevrolet. The 1976-77 Dura-Built 140 engine had improved engine block coolant pathways, redesigned head gaskit, water pump and thermostat and a 5 year/60,000 mile warranty.
Pontiac Astre
The Pontiac Astre was introduced in Canada September, 1972. Pontiac's version of the Vega was sold there exclusively for the 1973–1974 model years. Pontiac's trademark split grill, emblems, steering wheel, and Firebird styled tailights (notchback and hatchback) differentiate it from the Vega. Astre was introduced in the US two years later, September 1974 as a 1975 model and gave Pontiac dealers a needed fuel efficient subcompact.
Notchback, Hatchback, Safari Wagon, and Panel Delivery body styles were offered. The Astre used the Vega 140 cu in (2.3 L) engine through 1976. Transmissions are the 3 and 4-speed manual, 5-speed manual with overdrive (for 1976–77) and the 3-speed automatic. SJ models, optional on hatchback and wagon, feature soft nylon upholstery, cut pile carpeting, padded and cloth covered door panels, and a fabric headliner, plus rally instruments, the two barrel engine, four-speed or automatic (over a 3-speed manual) gearbox and radial tires. A GT package was optional for the hatchback and wagon.
A unique Lil Wide Track package was offered in 1975. It included a front air dam, rear spoiler, appliance wire mag rims, window louvers, a chrome exhaust tip, and bright stripe decals for the hood, body sides, rear spoiler, door handles, and wheel centers. The package added a little over $400 to the price of the Astre but dealers felt the difference in looks was worth the price. Production was switched from a warehouse in suburban Detroit to a factory beside the GM Lordstown Assembly plant. An estimated 3000 Lil Wide track Astres were ordered by dealerships. Eventually the components were offered as a dealer installed kit.
Pontiac introduced the 151 CID (2.5 L) OHV inline-4 engine for the 1977 model year. An updated version of Chevy's Nova engine last offered in 1970, the Astre used the engine for its final year. A new vertical design grill was used and Aluminum wheels (13") were a new option. Astre Formula was introduced, which included the handling package, chrome valve cover, three-piece spoiler, Formula T/A steering wheel and special decals. 1975-1977 (US) Astre Production 147,773
Car and Driver in a 1975 Astre road test, said, "For $180 over the price of a Vega, the Astre features upgraded interior trim-primarily the items for which Chevrolet charges $134 in their custom interior. You also have the opportunity to go one big step up in luxury if you choose the SJ line which is available in hatchback and wagon body styles."
Hot Rodding & Racing
V8 Vegas
Because of the Vega's design, light weight and low cost, it is often modified. A small-block Chevy V8 engine fits in the engine compartment; and a big-block will fit with modifications.
In 1972, Hot Rod magazine tested a Chevrolet prototype Vega featuring an all-aluminum V8. The fitted engine was the last of several 283 cu in units used in Chevrolet's Corvette research and development in the late 1950s, bored out to 302 cu in for the Vega application. Hot Rod's road test of the prototype with Turbo Hydramatic, stock Vega differential, and street tires yielded quarter mile times under 14 seconds. The Vega was not offered with a factory V8 option, however the Vega-based Monza did from 1975-79.
Motion Performance of Baldwin NY and Scuncio Chevrolet sold new, converted V8 small and big block Vegas. Heavy duty engine mounts and front springs were fitted to support the increased engine weight, a larger radiator for the increased cooling demand and modified driveshaft were required. For engines over 300 hp, or with a manual transmission, a narrowed 12-bolt differential replaced the stock Vega unit.
Drag racer Bill "Grumpy" Jenkins in the 1972 season, won six of eight National Pro-Stock division events with his '72 Vega Grumpy's Toy X small block. In its first entered event, the untested Vega ran low 9.6 second runs and won the 1972 Winternationals. Jenkins built and raced Pro-stock '74 Vega and '75 Monza drag cars. His Grumpy's Toy XI '74 Vega (pictured) sold for $550,000 in 2007.
Car and Driver's Showroom Stock #0
Car and Driver magazine challenged its readers to an SCCA sanctioned series of Showroom Stock races in the 70's at Lime Rock Park, Lime Rock Conn. In 1975, Patrick Bedard, Car and Driver writer and race car driver, piloted their 1973 Vega GT #0 in the Car and Driver Showroom Stock Challenge III and had just edged out an Opel to win the event.
Bedard recalls, "The lone Vega outran every single Opel, Colt, Pinto, Datsun, Toyota and Subaru on the starting grid. A 25 lap sprint into racing's hall of fame. From the summit of the winner's platform I could see the car over in the impound area, a metallic bronze coupe with a big yellow zero on its battle-scarred flank. I'd driven it there after the victory lap, water boiling out of the coolant tank, an anguished moan broadcasting from the cam drive, its left front tire chunked and rough. The tech inspectors had pushed it off the scales and were now probing under the hood, looking for the secrets of its speed. It had done the job, this Vega GT, faced off against 31 other well-driven showroom stockers and it had finished first. I was beginning to feel some warmth towards it..."
"It was clearly a car nobody cared about. The ad in the paper asked $2100. Average retail bluebook for a 1973 Vega GT was $2300. I thought about offering $2000 but I thought they'd jump at it. So I asked what they had to have for it. The old man said $1900..." "I talked to Doug Roe, an ex-Chevrolet engineer with a reputation as a Vega specialist. I mentioned our Vega showroom stocker. He grimaced. "Better overfill it about a quart," he said. "When you run them over 5,000 rpm, all the oil stays up in the head and you'll wipe the bearings. And something has to be done with the crankcase vents. If you don't it'll pump all that oil into the intake." "I hoped he was wrong but he wasn't. On its very first lap around Lime Rock our Vega blew its air cleaner full of oil. And it also ran 215 °F on the water temperature gauge. When I called Roe about the overheating, he said all Vegas run about that hot and it would be OK to about 230 degrees. Then it would probably start to detonate...I wasn't even convinced that it could finish. And I didn't even know all of its bad habits yet. Five laps from the end I discovered that once the tank drops below a quarter full, the fuel won't pick up in the right turns. Twice per lap the carburator would momentarily run dry. And if that wasn't bad enough, the temperature gauge read exactly 230 degrees and a white Opel was on my tail as unshakably as a heat seeking missle. But it was clear that no matter how good a driver Don Knowles was and no matter how quick his Opel, he wasn't going to get by if the Vega simply stayed alive. Which it did. You have to admire a car like that. If it wins, it must be the best, never mind all of the horror stories you hear, some of them from me."
See also
External Links
News and References
- Supercar Registry: Yenko Stinger II Vega
- Supercar Registry: Motion Phase III Vega
- How stuff works: Chevrolet Vega
- Car Survey.org: Reviews-Chevrolet Vega
- Car Domain Blog: Millionth Vega
- Car Domain: Chevrolet Vega
Enthusiast Sites and Discussion Forums
