Falling Star: The Checkered History of the Chevrolet Vega

It sounded so promising at the time. After years of dismissing imported compacts as cars for kooks, GM was finally going to build an attractive, sophisticated subcompact featuring the latest advances in manufacturing technology. To follow that, Chevrolet was going to offer a sporty version with a racy twin-cam engine built by the legendary English firm Cosworth. It was the car that was going to save America for American cars — that is, until it all went wrong. This is the story of the 1971-1977 Chevrolet Vega and 1975-1976 Cosworth Vega.

1971 Chevrolet Vega badge


It all had to sound very familiar. Back in the late 1950s, the Eisenhower recession had provoked a sudden flurry of interest in economical compact cars, of which American manufacturers of the time then offered very few. The market for imported cars, previously negligible, suddenly climbed to a worrisome 5% or so of the U.S. market. Each of the domestic automakers (except AMC, which already had compacts in the form of the Rambler and Rambler American) hastened to develop their own homegrown compact cars in hopes of driving the foreign invaders from American soil.

These not-terribly-small domestic compacts sold well, but they failed to reduce the growth of imported cars, which by the late sixties included Datsun and Toyota as well as the ubiquitous Volkswagen. By the middle of the decade, Detroit appeared to have given up and ceded the low end of the market to foreign competitors.

By Detroit standards, that was an eminently logical decision. In America, goodness was synonymous with bigness, particularly in the collective minds of the Big Three. They had considered compacts back in the forties, but abandoned the idea when they realized that they couldn’t build small cars any cheaper than they could full-size models. Other than AMC’s George Romney, most auto executives couldn’t imagine why anyone would want a smaller car if they could afford a big one. Even when Detroit finally, reluctantly introduced smaller cars, the resultant products tended to have a distinct loss-leader vibe. That too was customary Detroit logic; each step up the ladder meant a substantial increase in per-car profits, so anything you could do to convince a customer to choose a bigger car meant more money in your pockets. Who needed small cars, except perhaps to entice young buyers who might be enticed to later buy an Impala or a Caprice?

The flaw in that reasoning was that the fringe market kept getting bigger. By 1969, small cars accounted for 29% of the U.S. market and the total market share of the imports had risen to more than 11%. Volkswagen alone was now selling more than 500,000 cars a year in the U.S. Like it or not, the Big Three were going to have to respond — and soon.

In October 1968, GM chairman James Roche announced to the press that in two years, GM would build an new subcompact car codenamed XP-887, which he promised would feature new advances in engineering and manufacturing, but be priced to compete directly with the Volkswagen Beetle. The XP-887 would weigh about 2,000 lb (907 kg) and be powered by a small (by American standards — less than 150 cu. in./2.5 liters) OHC four. The XP-887, Roche declared, would show the world what General Motors could do.


To put this announcement in context, we need to step back about a decade to the development of what had previously been GM’s most complex and sophisticated small car: the Chevrolet Corvair. Shepherded by then Chevrolet general manager Edward N. Cole, the Corvair was a radically engineered compact featuring an air-cooled, rear-mounted aluminum engine; swing-axle independent rear suspension; and unit construction.

Some of the Corvair’s original technological ambitions had proved infeasible, but even in final form, the rear-engine compact was complex and expensive to build, which had prompted a last-minute cost-cutting program to bring the list price closer to more conventional rivals’. Despite those cuts, the Corvair didn’t sell as well as expected and some of the cost-reduction measures had exacerbated the design’s inherent tendency toward final oversteer. A series of accidents involving Corvairs resulted in lawsuits against GM, attracting unwelcome attention from consumer advocates like Ralph Nader.

Later iterations of the Corvair, although much improved, were overshadowed by Ford’s less-innovative but far more popular Mustang and the cheaper Chevy II, hastily rolled out in 1962 as a more conventional alternative to the Corvair. The second-generation Corvair was ultimately left to languish, finally expiring in 1969. Although it had sold almost 1.8 million units in 10 years, GM considered the Corvair something of an embarrassment and for several years it became the corporate equivalent of an Orwellian “unperson,” officially forgotten.

The Corvair’s woes did not hamper the career of Ed Cole, who also had many other achievements to his credit, including the development of GM’s two most successful modern V8 engines. Cole was promoted to group VP of car and truck operations in November 1961, executive vice president in July 1965, and president and chief operating officer in October 1967.

Cole still had strong ideas about small car design and as executive vice president and then as president, he had continued to pay close attention to compact car ideas being developed by the central Engineering Staff. Some of those had involved rear engines and appear to have been conceived as at least nominal successors to the Corvair, although by early 1967, development and styling work was also being done on front-engine designs. (Work on the last rear-engine concept, coded XP-892, continued until mid-1968, probably ending around the time the XP-887 project began.) It seems safe to assume, therefore, that the XP-887 was developed with a great deal of Cole’s direct input.

Like the XP-892 and the earlier front-engine XP-873, the XP-887 was not born as a Chevrolet. Its initial engineering package was developed by the Central Staff while the initial styling direction was set by the corporate Advanced studio, then led by Clare MacKichan (a former Chevrolet chief stylist who had previously led the development of the Opel GT as chief designer for Opel in Germany) and directly supervised by Styling VP Bill Mitchell. We don’t know to what extent Chevrolet engineers and designers were even aware of the XP-887 project prior to Roche’s announcement; during the tenure of general manager Pete Estes, Chevrolet had been pursuing its own plans for a subcompact, a smaller counterpart to the Chevy II/Nova powered by an all-new cast iron four.

According to John DeLorean, who took over as Chevrolet’s general manager in February 1969, the XP-887 was at a very nascent stage at the time of Roche’s speech. Most of the specifications, both technical and financial, were still essentially theoretical, created by extrapolating from various foreign-made subcompacts. This was more or less customary for corporate engineering projects in those days; the role of the Central Staff was not to develop production cars, but rather to come up with ideas and inventions that the divisions could then adapt for production. A variety of other, very successful products had originated in precisely that way, including the original Chevrolet Powerglide and Buick Dynaflow automatic transmissions.

However, in previous cases, the decision of whether or not to adopt a particular idea had usually rested with the division, subject to the ultimate financial oversight of GM corporate management. (The corporation would occasionally order multiple divisions to collaborate on a single project, but in this era, that was still the exception rather than the rule.) Furthermore, each division generally had a great deal of leeway when it came to adapting a particular concept to its own needs, facilities, and requirements, which is why different divisions’ versions of a particular invention or concept often differed significantly.

In this case, the corporation ordered Chevrolet to discard its own project — and canceled outright a similar one at Pontiac — in favor of the XP-887. Unsurprisingly, that order was greeted with considerable resentment from Chevrolet’s own engineering department, which was effectively being told — by their former boss, no less — that their own work wasn’t good enough. Moreover, Roche’s announcement had publicly committed the division to building what had been conceived as basically a pie-in-the-sky advanced engineering project, the promised specifications of which would not be easily achieved.


As they struggled to come to grips with the XP-887, DeLorean and his disgruntled staff quickly recognized that much of what the central Engineering Staff had just handed them was more wishful thinking than realistic proposal. Some of the estimates were outdated while others were off-target or simply inaccurate. Worse, the corporate design specifications didn’t necessarily even reflect GM’s own current policies; for example, there was no provision for the new corporately mandated side-guard door beams.

While Chevrolet chief design engineer Jim Musser (succeeded in early 1970 by Lloyd Reuss) worked to correct these shortcomings, Henry Haga’s Chevrolet Advanced styling studio revamped the exterior design to reduce the (coincidental) resemblance to Ford’s new Maverick and provide a stronger styling link to other Chevrolet models — particularly the new second-generation Chevrolet Camaro. Styling ended up being the Chevrolet subcompact’s most successful feature; if it didn’t quite qualify as sexy, it was certainly pleasant enough to look at, with overtones of both the Camaro and the Fiat 124 coupe.

The styling changes did not alter the fact that the XP-887 was now more than 10% over its original design and cost targets. Since that would be hard to fix without a major redesign that the corporation was not about to permit, Chevrolet’s marketing staff recommended positioning the XP-887 as an upscale subcompact in the manner of the early Nash Rambler, adding more features to help to justify a higher price.

The corporate Engineering Policy Committee recognized the logic of this proposal and gave their tentative approval. The plan was consistent with Chevrolet’s past experience; buyers of previous domestic compacts had shown a definite preference for plusher trim levels and the pricier Corvair Monza had consistently outsold the price-leader 500 by a substantial margin. However, shortly before launch, the Pricing Review Committee ordered Chevrolet to delete most of the additional features in hopes of bolstering the XP-887’s profit margins — an unwelcome echo of the launch of the Corvair.

1971 Chevrolet Vega panel front © 2008 Vegavairbob at English Wikipedia (Robert Spinello) (CC BY-SA 3.0 Unported)
The 1971 Chevrolet Vega’s resemblance to the 1970½ Chevy Camaro is most apparent from head on, particularly in the eggcrate grille and the shape of the bumper. (Photo: “1971 Chevrolet Vega” © 2008 Vegavairbob at English Wikipedia (Robert Spinello); resized and used under a Creative Commons Attribution-ShareAlike 3.0 Unported license)

The crowning indignity, so far as Chevrolet was concerned, was that the division was not even allowed to select its own name for the XP-887. As is customary, the Chevrolet marketing department had considered an assortment of names. One possibility that popped up in early press reports was “Chevette,” which Chevrolet would adopt a few years later, but the internal and consumer favorite was “Gemini,” which evoked NASA’s successful Project Gemini space missions of a few years earlier. Cole, however, would hear none of this and insisted on the name “Vega,” after a large white star in the constellation Lyra, although DeLorean said that name had tested poorly with consumers. Again, Cole got his way despite the division’s objections.

To build the Vega, Chevrolet invested heavily in expanding and modernizing its factory in Lordstown, Ohio. As Roche had promised, the modernization included a high level of automation, with Unimate robots performing most of the welding for the Vega’s unit body. The plant update revealed the corporation’s ambitious expectations for Vega sales: Lordstown now had an annual capacity of 400,000 units.


In size, the original Chevrolet Vega was about halfway between the Ford Maverick and a Volkswagen Super Beetle, stretching 169.7 inches (4,310 mm) on a 97-inch (2,464mm) wheelbase. In contrast to most import rivals, the Vega was quite low-slung; the two-door sedan had an overall height of 51.9 inches (1,318 mm), only half an inch (13 mm) taller than a 1969 Camaro, and the coupe was a mere 50 inches (1,270 mm) high.

The Vega had unitized construction and a conventional front-engine/rear-drive layout with rather slow recirculating ball steering (22.8:1, 4.4 turns lock to lock in standard form). Suspension was a conventional double wishbone layout in front and a live axle on coil springs in back, located by four trailing arms — essentially a scaled-down version of the Chevelle’s rear end. Front disc brakes survived the last-minute de-contenting (both the Volkswagen and Ford’s new Pinto had four-wheel drums), but the Vega’s standard transmission had three speeds rather than four; a four-speed manual was an extra-cost option, as was two-speed Powerglide automatic.

With a full tank of fuel, an early Vega weighed a bit under 2,300 lb (around 1,030 kg), which was about 210 lb (95 kg) more than a Pinto and over 300 lb (say, 140 kg) more than a Super Beetle. The Vega’s weight reflected Chevrolet engineers’ efforts to beef up the body structure as compared to the original XP-887 design, prototypes of which had continually broken during durability testing. Nonetheless, the Vega’s body was still not terribly robust and its corrosion resistance left much to be desired, in part because the cost-cutting spree had left the Vega with unlined fenders that were easily damaged by road salt.

1971 Chevrolet Vega front © 2005 Barnstarbob at English Wikipedia (Robert Spinello) (CC BY-SA 3.0 Unported)
The first 1971 Chevrolet Vega off the assembly line. (Photo: “1st Vega built” © 2005 Barnstarbob at English Wikipedia (Robert Spinello); resized and used under a Creative Commons Attribution-ShareAlike 3.0 Unported license)

In most respects, however, the Vega was a perfectly conventional small Chevy, not terribly different from its larger Nova and Chevelle cousins in design or mechanical. Its most unique feature — and its real Achilles heel — was its engine.


The Chevrolet Vega’s engine, known as the 2300, was an all-new inline-four with a single overhead camshaft — a first for Chevrolet and a rarity for American engines of the period. With a displacement of 140 cu. in. (2,286 cc), the 2300 was big for the economy-car class, with undersquare dimensions for strong low-end torque. More significantly, as GM had promised and Cole had insisted, the new engine, which was made on the Massena, New York, line that had previous produced Corvair engines, featured an aluminum cylinder block, something GM hadn’t offered since it sold its all-aluminum V8 to Rover in 1964.

While aluminum cylinder heads were relatively common on non-U.S. engines — the press initially expected Chevrolet to use an aluminum head on an iron block — aluminum blocks were still very rare. The main reason was cost; although aluminum is significantly lighter than iron (a very attractive quality for passenger vehicles, in which the engine is usually the largest single mass), it is also substantially more expensive than iron to produce, buy, and machine. Furthermore, cast aluminum is significantly softer than cast iron, creating problems with premature wear of the cylinder bores. Adding iron or steel cylinder liners mitigates the wear issues, but raises costs even further.

Since the late fifties, GM’s Engineering Staff had been looking for ways to avoid that extra cost with aluminum cylinder blocks that would not require cylinder liners. To that end, GM and Reynolds Aluminum had devised a new aluminum alloy called A390 that, when properly finished, provided a much harder bore surface durable enough to make cylinder liners unnecessary. Cole had been interested in this process since the late fifties, drawn by its potential cost and labor savings; he had actually wanted to use it for the Corvair’s engine, although at the time, that had proved impossible. On the Vega, GM claimed the elimination of pressed-in or cast-in iron liners saved a useful $8 per engine, although each block still cost more than an equivalent cast iron one.

1971 Chevrolet Vega engine © 2009 Vegavairbob at English Wikipedia (Robert Spinello) (CC BY-SA 3.0 Unported)
The Chevrolet Vega’s engine had a 3.50-inch (89mm) bore and 3.63-inch (92.1mm) stroke, giving a total displacement of 140 cu. in. (2,286 cc). At introduction, the engine’s rated output was 90 gross horsepower (67 kW) with a single-throat carburetor and 110 hp (82 kW) in optional L11 two-barrel form. Net ratings were 80 hp (60 kW) and 93 hp (69 kW) respectively, revised to 80 and 90 hp (60 and 67 kW) for 1972 and 72 and 85 hp (54 and 63 kW) for 1973. (Photo: “Vega 140 Engine” © 2009 Vegavairbob at English Wikipedia (Robert Spinello); resized and used under a Creative Commons Attribution-ShareAlike 3.0 Unported license)

There was nothing conceptually wrong with the Vega’s linerless cylinder block; Cosworth later found that it wasn’t strong enough for serious racing use, but it was adequate for street use and except for some early casting problems, bore wear was normally very low. Indeed, linerless aluminum blocks are very common today and generally experience few problems. However, the aluminum block made the Vega’s engine more sensitive to overheating, particularly in combination with the cast iron cylinder head, specified for cost reasons. (Curiously, the Vega’s iron head actually weighed more than the engine block, making the engine somewhat top-heavy.)

Among their differences, iron and aluminum have very different heat-conduction and expansion rates. If an aluminum/iron engine overheats, the aluminum side will expand faster than the iron side, putting considerable stress on the head gasket (which mates the head to the block) and eventually causing it to fail. Since aluminum is softer than iron, severe overheating can also cause the aluminum to warp, resulting in permanent damage.

That issue was by no means unique to the Vega — engines with aluminum heads and iron blocks run the same risk — but the Vega’s aluminum cylinder block was also vulnerable in another way: Severe overheating would break down the silicon content of the A390 alloy, leaving soft areas in the cylinder bores that would be quickly scuffed and scored by the pistons.

As long as the engine remained within normal operating temperatures, none of this was likely to occur. However, the cost-cutting binge had left the Vega with an undersized radiator and no coolant overflow tank. Coolant temperatures would climb quickly in strenuous conditions, such as pulling a heavily laden car up a long mountain grade on a hot summer day. If the engine did begin to boil over, it would also lose coolant, eventually running itself dry. As a result, any serious cooling system problem, like a failed thermostat, was a recipe for serious engine damage.

This problem was compounded on early engines by excessive oil consumption. The thirst for oil usually had little to do with the aluminum block per se; the main culprits were the valve stem seals, which would crack with age or wear and leak oil into the cylinders. Since engine oil is partly responsible for engine cooling as well as lubrication, the resulting tendency to run a quart low only exacerbated the 2300 engine’s vulnerability to overheating.

Beyond that, the Vega engine simply was not a very pleasant companion. It had adequate power, but it was disturbingly noisy when revved and quite rough. Four-cylinder inline engines have an unbalanced coupling force that causes the engine to rock up and down; the bigger the displacement (in particular, the longer the piston stroke), the greater the shake. Modern fours generally quell these forces with twin counter-rotating balance shafts, but that technology was not well-developed when the Vega was designed. (Although English inventor Frederick Lanchester had first patented the balance shaft concept back in 1912, Mitsubishi’s well-known “Silent Shaft” system wasn’t patented until 1973). Even if it had been available, Chevrolet would probably have deemed it too expensive, particularly if it involved patent license fees. Instead, Chevrolet used very soft engine mounts, hoping to isolate the shaking from the passenger compartment.

The soft engine mounts may have contributed to another early Vega problem: loose carburetor mounting bolts that could allow raw fuel to leak into the cylinders, potentially resulting in either dramatic backfiring or an engine fire. In April 1972, Chevrolet recalled about 130,000 Vegas to correct that problem, which cost the division both money and credibility. So too did a larger recall of 350,000 early Vegas to fix another, unrelated carburetor problem that could lead to the throttle linkage jamming in the part-throttle position.

1971 Chevrolet Vega rear 3q © Aaron Severson
This battered, primer-gray 1971 Chevrolet Vega GT is missing one of its taillights, but gives a good sense of the original rear profile. Slots on the hatch are the exhaust vents for the flow-through ventilation system. The Vega GT included a heavy-duty suspension, front and rear anti-roll bars, bigger tires (although not as big as the fat boots on this heavily modified example), and a new instrument cluster with a tachometer. A four-speed manual transmission, Positraction limited-slip differential with 3.36 axle ratio, and the up-rated L11 engine completed the package.


Thanks to the cost and weight overruns, the Chevrolet Vega was introduced to the public in September 1970 with base prices starting at $2,091, about 10% more than the Volkswagen Super Beetle that had been its original target. The Vega was also $101 more than a two-door Datsun 510, $173 more than a Toyota Corolla 1600, and $172 more than the new Ford Pinto. Despite its high price, the Vega was also one of the most Spartan cars in it class, sacrificing many of the minor amenities that were standard on its import foes, like carpeting and even a glove box.

In other quantitative respects, the Vega made a decent case for itself. Even in base form, it was capable of 0-60 mph (0-97 km/h) in less than 14 seconds, quicker than most direct rivals other than the bigger and considerably thirstier AMC Gremlin; top speed was around 90 mph (145 k/h). The Vega was also capable of a respectable 25–27 mpg (8.7–9.4 L/100 km), handled quite well despite its slow steering, and had a reasonably civilized highway ride.

1971 Chevrolet Vega panel truck side
In addition to the two-door sedan and the three-door hatchback coupe, the Chevrolet Vega was offered either as a Kammback two-door wagon or as this two-door Panel Express (essentially the Kammback wagon without side glass). The wagon was more than $200 more expensive than the sedan, so it accounted for relatively few sales. (Photo: “1971 Chevrolet Vega Panel” © 2008 Vegavairbob [Robert Spinello] at en.wikipedia; resized and used under a Creative Commons Attribution-ShareAlike 3.0 Unported license)

All that sounded great on paper, but the Vega was less impressive in the real world. The admirable economy was achieved by combining widely spaced gears with a yawning 2.53:1 rear axle that left the engine easily overtaxed by steep hills and the comfortable ride was achieved at some cost in axle control, particularly in panic stops. The interior ambiance was rather dreary in standard form and not all that roomy considering the Vega’s size and weight. You could mitigate some of these complaints with the options list — a GT with the available four-speed transmission and 3.36 axle was a good deal quicker than the base car, if less economical — but that pushed the price even further above the subcompact pack.

Motor Trend inevitably named the Vega its 1971 Car of the Year, but Chevrolet soon found that capitalizing on that praise — and the Vega’s multimillion-dollar ad campaign — would not be easy. Shortly after the Vega’s public debut, GM was hit by a lengthy UAW strike, provoked in part by internal union conflicts following the death of UAW leader Walter Reuther in a plane crash earlier that year. As a result, production halted for weeks and Chevrolet dealers had fewer than 25,000 Vegas to sell until mid-January 1971. The strike limited first-year Vega sales to 277,705 units, which was well below the 400,000-unit target. Sales for 1972 climbed to 394,592, which was more what Chevrolet had in mind.

Whatever their design flaws and engine-casting issues, early Vegas were reasonably well assembled by American standards, but quality took an ugly turn in 1972. The Lordstown plant had previously been run by Fisher Body, but in the fall of 1971, GM turned over control to the GM Assembly Division (GMAD), looking to reduce costs. GMAD immediately laid off some 700 workers — including the quality-control inspectors DeLorean had added — while upping production from 60 cars an hour to 100 an hour.

Predictably, assembly quality began to drop. Workers protested that they no longer had time to do a good job, but it was to little avail. Accusations of deliberate sabotage and GMAD managers’ heavy-handed approach to discipline (which allegedly included sending workers home for minor infractions like unauthorized bathroom breaks) led workers to call another strike in early 1972, but it ultimately earned them nothing. The Vega soon became one of the worst-built models in the Chevy line-up and owners complained that Chevrolet dealers often seemed unprepared to fix the cars if something went wrong.

1973 Chevrolet Vega GT front 3q © 2008 Vegavairbob at en.wikipedia (Robert Spinello) (CC BY-SA 3.0 Unported)
The Chevrolet Vega sold well for much of its lifespan; this is the millionth Vega, a 1973 Vega GT coupe. If you look closely, you can see that the front bumper is stouter than that of the 1971 above. In 1973, the front bumper was beefed up to meet federal crash standards, adding 179 lb (81 kg) to the Vega’s weight. The 1973 models also had various detail improvements, including revised gearing, improved shift linkage, and a certain reduction in engine noise and thrash. The 1974 models had even stouter bumpers, a new slanted grille, and a bigger fuel tank, raising curb weight an additional 150 lb (68 kg). (Photo: “1973 Chevrolet Vega GT-Millionth Vega” © 2008 Vegavairbob at en.wikipedia (Robert Spinello); resized and used under a Creative Commons Attribution-ShareAlike 3.0 license)

Still, once production was up to speed, neither these woes nor customer complaints about rust, overheating, and backfiring seemed to affect sales. Chevrolet sold 427,300 Vegas for 1973 and an impressive 460,374 for 1974, bolstered by the OPEC oil embargo that began in late 1973.


Whatever its other foibles, the Chevrolet Vega coupe was a fairly sporty piece, particularly with the optional L11 engine, four-speed transmission, F41 handling suspension, bigger tires, and Positraction limited-slip differential. It was clear that the basic package could handle more power than the standard engine provided.

In March 1970, John DeLorean and Chevrolet assistant chief engineer Lloyd Reuss (who as mentioned above had previously been Vega’s chief project engineer) contacted Britain’s Cosworth Engineering about the possibility of developing a special racing version of the Vega engine. Established in 1958 by Mike Costin and Keith Duckworth, Cosworth was one of the world’s preeminent builders of racing engines, prominent in Formula One and other forms of motorsport. Up until that time, Cosworth had been most closely associated with Ford, which offered the DOHC Cosworth BDA engine in some British and European models for homologation purposes, but Duckworth was amenable to the Chevrolet proposal, seeing it as a way of broadening Cosworth’s options.

1976 Chevrolet Cosworth Vega name © Aaron Severson
The 1975-1976 Chevrolet Cosworth Vega carried its identification on the tail, inboard of the taillights.

Reuss assigned the project to veteran Chevrolet performance engineer Cal Wade, who worked closely with Cosworth engineer Mike Hall to develop a dual overhead cam 16-valve version of the Vega 2300 engine that could be reduced to less than 2,000 cc (122 cu. in.) displacement for Formula Two. Although the project was originally intended strictly for competition, Wade suggested to DeLorean that a street version of the new engine would turn the standard Vega — which at that point had not yet been released — into a formidable sports coupe. Chevrolet chief engineer Don McPherson was extremely skeptical, but DeLorean was intrigued and authorized Wade to keep working on the idea.

The first running prototype of the 16V DOHC Cosworth Vega engine, completed in June 1970, used dual carburetors, but Wade wanted to substitute electronic fuel injection, which would provide greater flexibility and better emissions performance than either carburetors or mechanical injection systems while offering Chevrolet additional technological bragging rights. To that end, Wade approached Bendix, which had briefly introduced and then hastily dropped its advanced “Electrojector” system about 15 years earlier. Bendix in turn pitched the idea to DeLorean.

Both DeLorean and Bendix were enthusiastic about the idea of a fuel-injected Vega engine, which they saw as a stepping stone to offering the electronic injection system on other Vegas and eventually other Chevrolets — big business for Bendix. Thus inspired, DeLorean ordered a marketing study of the potential viability of a performance Vega powered by the fuel-injected twin-cam engine. Marketing consultant Gertrude “Jimmy” McWilliams (former advertising manager of Triumph’s U.S. organization and wife of British-Leyland executive Bruce McWilliams) studied the problem and concluded that if the performance was up to snuff, there would be a potential market of at least 30,000 units a year.

In the spring of 1972, DeLorean got Ed Cole and Corvette chief engineer Zora Arkus-Duntov to drive a prototype of Wade’s super-Vega and secured approval for an initial run of 5,000 cars. DeLorean also got permission for a license agreement with Cosworth Engineering that would allow the production cars to carry the Cosworth name.

It was about then that the trouble began. Cosworth hit the wall in its efforts to produce a viable racing version of the Vega. The standard aluminum block castings turned out to have a safe limit of 270 hp (201 kW), 20–30 hp (15–22 kW) shy of what a Formula 2 version of the Chevrolet engine would need. (By this time, Cosworth’s Ford-based BDA twin-cam engine was making around 240 hp (179 kW) in Group 2 rally tune.) The only solution was to make extensive changes to the Chevrolet’s block casting process, which the Massena engine plant was neither able nor willing to undertake; Cosworth finally gave up in the spring of 1973.

Meanwhile, Chevrolet’s street version, originally slated for a mid-1973 introduction, was running behind schedule. Wade had hoped for 185 hp (138 kW) in street form, but noise and emissions regulations made that impossible and even at 130–140 net horsepower (97–104 kW), he and McPherson still not sure the twin-cam engine could pass the EPA’s 50,000-mile (80,000-km) durability test. (McPherson, for his part, maintained that the whole project was a hopeless boondoggle.) They finally opted to delay emissions certification rather than risk failing the time-consuming durability test and having to start over.

1976 Chevrolet Cosworth Vega engine © Aaron Severson
The Chevrolet Cosworth Vega Z09 twin-cam engine. The production engine was ultimately far more Chevrolet than Cosworth, although it was very sophisticated for its time, offering dual overhead cams, four valves per cylinder, electronic fuel injection, and electronic ignition. GM would not offer another 16-valve DOHC fuel-injected four-cylinder engine until the ill-fated Quad 4, launched more than 20 years later.

Eager to bring the Vega some positive publicity, Chevrolet general manager Jim McDonald (who had replaced DeLorean in October 1972) decided to announce the Cosworth engine anyway, even allowing some magazine editors to drive the preproduction prototypes. The announcement generated great excitement in the enthusiast press and drew interest from GM’s Australian and German subsidiaries, Holden and Opel, and Jensen’s Kvell Qvale. Dealers started taking customer deposits for Cosworth Vegas and waiting lists began to form in anticipation of McDonald’s claimed mid-1974 launch date.

Unfortunately, the 1974 model year came and went and the car was still not ready. As Wade and McPherson had feared, the twin-cam engine failed its EPA durability test. Not only did that mean starting over, the engine would now have to meet the more stringent 1975 standards, which would require adding air injection (something Wade had hoped to avoid), a catalytic converter, and changes to support the use of unleaded gasoline. The revised engine didn’t complete its durability testing until January 1975 and didn’t receive its EPA certification until March. As a result, the Cosworth Vega’s public debut was delayed until April 17, late in the model year and almost two years after the original announcement.

The Cosworth engine’s technical specifications were impressive. It retained the standard Vega’s aluminum block, but had a forged, hardened crankshaft with a shorter throw that reduced stroke to 3.16 inches (80 mm) and total displacement to 122 cu. in. (1,995 cc). The entirely new head was aluminum, with pentroof combustion chambers and dual camshafts in a detachable aluminum carrier. The valves, which were smaller in diameter but more numerous than those of the standard eight-valve Vega 2300 engine, were actuated via inverted bucket-type tappets and had sintered iron seats to allow the use of the unleaded fuel the catalytic converter demanded. The breathing improvements provided by the greater total valve area allowed a milder cam profile than that of the regular Vega GT engine, which, combined with the shorter stroke and smaller displacement, made the Cosworth engine both more powerful and significantly smoother than its 2.3-liter sibling.

In addition to Bendix electronic fuel injection, the twin-cam Cosworth engine featured high-energy electronic ignition and special low-restriction stainless steel headers with a novel “Pulse Air” air-injection system that consumed less power than did a conventional air pump. Even with those changes, the complete engine had a dry weight of only 305 lb (138 kg), compared to about 345 lb (157 kg) for the iron-head Vega engine.

For all its technological credentials, the Cosworth Vega engine’s output was disappointing. Chevrolet initially claimed 120 hp (90 kW), but that was hastily revised to 111 and finally 110 net horsepower (82 kW) at 5,600 rpm with 107 lb-ft of torque at 4,800 rpm. (On paper, the Z09 Cosworth sounded no more powerful than the Vega GT’s carbureted L11 engine of 1971, but the latter’s 110 hp was an SAE gross rating; by 1975, the L11 was advertised at a more realistic 87 net horsepower (65 kW).) The Cosworth’s 110 hp was certainly not bad — in fact, it was almost spot on the similarly sized engine in the BMW 320i, which appeared the following year — but it was not the junior Supercar Chevrolet had been promising.

1976 Chevrolet Cosworth Vega dash © Aaron Severson
An “engine-turned” dash appliqué was standard on the Chevrolet Cosworth Vega, as were a tachometer and voltmeter; for some reason, the stock Vega still only had an oil-pressure warning light. (The accessory gauges to the right of the main cluster are not stock.) This 1976 Cosworth has the Borg-Warner five-speed manual, which was added to the options list in 1976. The five-speed included a shorter final drive ratio (4.10, versus 3.73 with the four-speed) for better acceleration. Only about half of the 1976 Cosworths were so equipped.


Despite the mediocre output and a hefty curb weight of 2,760 lb (1,252 kg), the Cosworth Vega was reasonably quick, capable of 0-60 mph (0-97 km/h) in around 9 seconds and a top speed of up to 112 mph (180 km/h). Those were not muscle car figures, but they were quite good for the performance-challenged mid-seventies. Thanks to a new rear suspension with three trailing links and a Panhard rod (borrowed from the new H-body Chevrolet Monza and added to other Vegas for 1976), the Cosworth’s handling was even better than the standard Vega’s and a match for almost any sporty coupe of its time.

Unfortunately, the Cosworth Vega was not priced like other sporty coupes. With a starting price of $5,979, it cost twice as much as a regular Vega coupe, over $2,000 more than a V8 Camaro, and $300 more than a Datsun 260Z. Chevrolet twisted the knife by advertising the Cosworth Vega as “One Vega for the Price of Two” — not exactly an enticing or politic tag line for owners of early Vegas that had ended up needing warranty engine replacements.

1976 Chevrolet Cosworth Vega front 3q © Aaron Severson
By 1975, federal 5 mph (8 km/h) bumpers had added 5.7 inches (170 mm) to the Chevrolet Vega’s overall length, bringing it to 175.4 inches (4,455 mm). Curb weight had also swelled considerably; the Cosworth Vega weighed 2,760 lb (1,252 kg), about 320 lb (145 kg) more than an early Vega GT coupe.

Chevrolet built a total of 2,061 Cosworth Vegas for 1975. At first, dealers found them to be effective showroom traffic builders, but interest evaporated quickly when customers learned that the list price was almost $6,000. Many early Cosworths ended up being sold at steep discounts and dealers were more cautious about ordering cars for 1976. Total ’76 orders amounted to only 1,446, about half what Chevrolet had expected. At that point, Chevrolet general manager Bob Lund (who had replaced McDonald in December 1974) decided that enough was enough. The Cosworth Vega was discontinued in July 1976 and many unused engines were scrapped.

All Vega sales were on the decline by 1975, partly because of the car’s increasingly spotty reputation and partly because of internal competition from the Monza and its H-body siblings, the Buick Skyhawk, Oldsmobile Starfire and Pontiac Astre. The H-bodies shared the Vega’s basic body shell, but had fresher styling and could ordered with V6 or V8 engines, which were less economical but more reliable than the Vega’s four. Overall Vega sales slumped to 207,764 for 1975, falling to 160,524 the following year, when Chevrolet introduced the new subcompact Chevette.

By that time, Chevrolet had at least mitigated many of the Vega’s more serious problems. By 1974, the major recall campaigns were over and rust protection had progressively improved. The four-speed manual transmission belatedly became standard for 1976 along with an updated “Dura-Built 140” engine featuring improved cooling and oil circulation, a new coolant expansion tank with low-coolant warning light, a stronger head gasket, new valve stem seals, hydraulic valve lash adjusters, and iron-coated aluminum pistons. Chevrolet even offered a five-year, 60,000-mile (96,600-km) engine warranty in an expensive attempt to regain consumer confidence.

Still, sales fell to 78,402 for 1977, the Vega’s final year. The derivative H-bodies survived through 1980, but in their last three years, the previously standard Vega four was replaced by Pontiac’s 151 cu. in. (2,471 cc) “Iron Duke” engine.

1976 Chevrolet Cosworth Vega front © Aaron Severson
The 1975 Chevrolet Cosworth Vega was available only in this black-and-gold livery (although this car lacks the original gold-painted aluminum wheels), although there was a choice of black or white vinyl upholstery. In 1976, Cosworth Vegas were available in any standard Vega color. The three-slat grille, added in 1974, was one of the only notable styling changes during the Vega’s lifespan; it was revised a bit in 1976. Either way, we find it decidedly less attractive than the original eggcrate grille.

Stillborn — perhaps mercifully so — was Ed Cole’s last great ambition: the GM Rotary Combustion Engine. The two-rotor RC2-206 version of the rotary engine, developed at staggering expense (including at least $50 million in patent licensing fees), was intended as the sole engine for the H-body cars and by some accounts was originally supposed to debut on the 1974 Vega. However, the GM RCE program had an extremely troubled development and in September 1974, Cole announced that the rotary engine had been shelved, essentially admitting defeat.


As with the Corvair, any statements about the Vega’s failure have to be carefully qualified. Chevrolet sold more than 2 million Vegas during its seven-year lifespan, which is excellent by any standards. During the difficult period of the OPEC embargo — which briefly made big cars almost unsaleable — Chevrolet sold all the Vegas they could build. We’re not sure if the division actually made a profit on the Vega itself, particularly considering its high warranty costs, but if we factor in the sales of the derivative H-body Monza, they probably came out ahead. What it cost the division in customer good will is harder to measure.

The Chevrolet Vega story is eerily reminiscent of the Corvair’s history in many respects. Like the Corvair, it walked an uneasy line between high-tech sophistication and cheap-and-cheerful basic transportation. Like the Corvair, it embodied a number of perfectly sound concepts that were tarnished by clumsy execution. And like the Corvair, it had significant flaws that probably wouldn’t have been insurmountable had it not been for short-sighted, last-minute cost-cutting.

1976 Chevrolet Cosworth Vega rear 3q © Aaron Severson
The 1975 Chevrolet Cosworth Vega introduced a new rear suspension that was subsequently adopted for all 1976-77 Vegas. Instead of four trailing links, it located the live axle with two trailing arms, a single torque arm, and a Panhard rod. All Vegas had front-disc/rear-drum brakes, although Cosworths had heavy-duty semi-metallic pads. Note the simpler one-piece tail lamps, added for 1976. In contrast to the front end, we find them more attractive than the original shape, looking more European and less like a Ford Maverick.

As of this writing, GM is preparing to launch the Chevrolet Volt, a plug-in hybrid intended to demonstrate GM’s engineering mojo and trump the Toyota Prius and Honda Insight. If you’ve followed the Volt’s somewhat torturous development, there are disconcerting echoes of the Corvair and Vega: cutting-edge technology, grand promises, and significant cost and weight overruns, all married with a curious sense of executive ambivalence. (Product czar Bob Lutz, at whose behest the Volt show car is being transformed into a production vehicle, has made no secret of his preference for thirsty V8 muscle cars and has publicly declared his disbelief in global warming.) The Volt is of undoubted technical interest, but given GM’s track record in this area, we only hope that its story has a happier ending.

# # #


Our sources for the story of Vega’s troubled development history included “A reminder on auto recalls,” Kiplinger’s Personal Finance Vol. 26, No. 8 (August 1972), pp. 14–16; the Auto Editors of Consumer Guide, Encyclopedia of American Cars: Over 65 Years of Automotive History (Lincolnwood, IL: Publications International, 1996); “Bye-Bye, Rotary Vega — Hello, V-8,” Motor Trend Vol. 26, No. 4 (April 1974), p. 24; Chevrolet Motor Division of General Motors Corporation, “Chevy’s New Little Car Is Open for Business” [brochure 1102], ca. September 1970; “1976 Vega: Built to take it” [brochure 3317], September 1975; “’74 Vega” [brochure 2677-Rev], January 1974; “The Little Car That Does Everything Well” [brochure 1619], September 1971; “The Little Car That Does Everything Well” [brochure 2229], September 1972; and “Vega 2300: Why and How It Came About” [dealer brochure], 1970; “Comparison Test Super Coupes ’74: Mazda RX-2, Open Manta Rallye, Toyota Celica GT, Capri 2800, Vega GT, Mustang II Mach I,” Car and Driver Vol. 19, No. 11 (May 1974), pp. 58–69, 86; Robert Cumberford, “Who Killed the Corvair?” Car and Driver Vol. 15, No. 2 (August 1969) pp. 34-35, 73; “Cole, Edward N.” (n.d., GM Heritage Center, history. gmheritagecenter. com, accessed 27 August 2009); Corvette Museum, “2011 Corvette Hall of Fame Clare MacKichan,” YouTube, https://youtu.be/KNkDFmTzUBo, uploaded 17 November 2011, accessed 8 April 2012; Mike Covello, Standard Catalog of Imported Cars 1946-2002, Second Ed. (Iola, WI: Krause Publications, 2001); Jim Dunne, “Detroit Report…” Popular Science Vol. 193, No. 6 (December 1968), p. 30; “Detroit Report…” Popular Science Vol. 194, No. 2 (February 1969), p. 48; “Detroit Report…” Popular Science Vol. 194, No. 5 (May 1969), p. 48; “Detroit Report…” Popular Science Vol. 195, No. 4 (October 1969), p. 26; and “Detroit Report…” Popular Science Vol. 196, No. 1 (January 1970), p. 36; Robert F. Freeland, The Struggle for the Control of the Modern Corporation: Organizational Change at General Motors, 1924–1970 (Cambridge: Cambridge University Press, 2001); John Gunnell, ed., Standard Catalog of American Cars 1946-1975 Revised 4th Edition (Iola, WI: Krause Publications, 2002); David Halberstam, The Reckoning (New York: William Morrow and Company, 1986); H-Body FAQ, n.d., h-body. org/library/hbodyfaq/hbodyfaq-1.html, accessed 27-28 August 2009; John B. Hege, The Wankel Rotary Engine: A History (Jefferson, NC: McFarland & Company, Inc., 2001); “Inside Detroit,” Motor Trend Vol. 21, No. 5 (May 1969), pp. 11-12; Michael Lamm, “Martyr,” Special Interest Autos #22 (May 1974), reprinted in Corvair Performance Portfolio 1959-1969, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1998), pp. 132-140; Richard Langworth, “Corvairs for the ’70s: What Chevy Might Have Built,” Special Interest Autos #68 (April 1982), pp. 20-27; Karl Ludvigsen, “GM’s Wankel: The $700 Million Miscalculation,” Motor Trend Vol. 27, No. 3 (March 1975), p. 53; Hirokazu Nakamura, Hikoichi Motoyama, Tadahiko Ito, and Seizo Iwasa, assignors to Mitsubishi Jidosha Kogyo Kabushiki Kaisha (Mitsubishi Motors Corporation), U.S. Patent No. 3,995,610A, “Four Cylinder Straight-Type Engine with Secondary Balancer System,” filed 27 September 1974, issued 7 December 1976; Jan P. Norbye and Jim Dunne, Pontiac 1946-1978: The Classic Postwar Years (Osceola, WI: Motorbooks International, 1979); the Old Car Manual Project Old Car Brochures website, oldcarbrochures.org; Ken Polsson, “Chronology of Chevrolet Corvettes,” 4 April 2012, kpolsson. com/vettehis/, accessed 18 April 2012; Arthur Pound, The Turning Wheel: The Story of General Motors Through Twenty-Five Years 1908–1933 (Garden City, NY: Doubleday, Doran & Co., Inc., 1934); Joe Sherman, In the Rings of Saturn (New York: Oxford University Press, 1994); Alfred P. Sloan with John McDonald, My Years with General Motors (Garden City, NY: Doubleday, 1964); Robert Spinello, “Complete Vega History 1970-1977,” H-body.org, n.d., www.h-body. org/library/ vegabob/vega-history-complete.html, accessed 27 August 2009; Daniel Strohl, “Might Mouse: The diminutive, but sporty, 1969 Opel GT 1.1L,” Hemmings Sports & Exotic Car #7 (March 2006); “Vega,” Sol Station, 2012, www.solstation. com/ stars/ vega.htm, accessed 14 June 2015; Mark Wan, “AutoZine Technical School: Engine Smoothness,” AutoZine.org, 1998–2000, www.autozine. org/technical_school/ engine/smooth1.htm; Joseph White and Paul Ingrassia, Comeback: The Fall & Rise of the American Automobile Industry (New York: Simon & Schuster: 1995); J. Patrick Wright, On a Clear Day You Can See General Motors: John Z. DeLorean’s Look Inside the Automotive Giant (Chicago, IL: Avon Books, 1980); and Wally Wyss, “Vega Rotary: Ford’s New Mustang II forces GM to debut its Wankel a year early,” Motor Trend Vol. 25, No. 7 (July 1973), pp. 50–52, 123.

We also consulted the following period articles: “Ford Pinto and Chevrolet Vega 2300: Detroit’s Compact Commitment,” Car and Driver Vol. 16, No. 3 (September 1970), pp. 25-30; “A Small World to Conquer: Six-Car Comparison Test: AM Gremlin, Chevrolet Vega 2300, Ford Pinto, Simca 1204, Toyota Corolla, Volkswagen Super Beetle,” Car and Driver Vol. 16, No. 7 (January 1971), pp. 20-29; “Road & Track Owner Survey: Vegas 2300,” Road & Track Vol. 24, No. 10 (June 1973), pp. 87-90; “Super Coupe Comparison Test,” Car and Driver Vol. 16, No. 6 (December 1971), pp. 25–32, 68–70; “1973 Chevrolet Vega,” Road & Track Vol. 24, No. 10 (June 1973), pp. 90-91; and John DeLorean, “Vega 2300”; Bill Sanders, “Vega: 2300”; Jim Brokaw, “Basic Sedan”; Bill Sanders, “GT Coupe”; and Jim Brokaw, “Wagon” all from Motor Trend Vol. 22, No. 8 (August 1970).

Additional information on the Cosworth Vega came from Arch Brown, “1975 Chevrolet Cosworth Vega: Twin-Cam, Quad-Valve Pace-Setter,” Special Interest Autos #129 (May-June 1992), pp. 38-45; Chevrolet Merchandising Department, Passenger Cars, “Chevrolet Introduces the Cosworth Twin Cam” [launch brochure], March 1975, and “Cosworth. One Vega for the Price of Two” [advertisement, ca. 1975]; Mike Cook, “Passing of a Pioneer,” Hemmings Sports & Exotic Car #20 (April 2007); John Dinkel, “Cosworth Vega for the Road,” Road & Track Vol. 24, No. 12 (August 1973), pp. 30–34; Don Sherman, “How to Hatch an Engine, Car and Driver Vol. 21, No. 4 (October 1975), pp. 73–83; Jeremy Walton, Escort Mk 1, 2 & 3: The Development & Competition History (Sparkford, England: Haynes Publishing Group, 1985); and “A Cosworth Vega History,” CosworthVega.com, n.d., www.cosworthvega. com/ cosworth_vega_history.html, accessed 28 August 2009.

The derogatory attitude of one Chevrolet executive toward import buyers — perhaps the most pointed expression we’ve ever heard of Detroit’s attitude towards imports during that period — was mentioned in Eric Dahlquist, “Declutching the BUG,” Motor Trend Vol. 20, No. 7 (July 1968), pp. 70-73. Bob Lutz’s comments about global warming were originally reported by Glenn Hunter, D Magazine 30 January 2008, frontburner.dmagazine. com; we originally read it in Frank Williams, “Lutz on Global Warming: ‘It’s a crock of shit,'” The Truth About Cars, 12 February 2008, www.thetruthaboutcars. com, accessed 12 February 2008.



Add a Comment
  1. [quote]Oh, the 1973 bumper was the same as the ’71-72, just with longer supports and a filler plate. I guess the thinking was to minimize sheet metal damage by moving it out a bit.[/quote]

    More to minimize intrusion into the unibody. The federal regulations said that there had to be no structural damage from a low-speed frontal hit, so the idea was to absorb the impact before it got to the body structure.

  2. I remember by 1977-78, there were used 1971 Vegas in classified ads asking for $50! By 1990, Vegas were ‘extinct’.

    1. Obviously you don’t know how many of those $50.00 Vegas are still in the 2000 years owned by enthusiast that can ignore the shortcomings of management and have built some of the sharpest flat track 10 second cars I happened to own a 1977 Vega wagon that now has a 1974 Corvette stingray frame. The only thing I had to do was move two body bushings,believe it or not the spindles and rear axles just loved it how it just melded like pea’s in a pod. And it’s so nice to own a ,1973 GT,a 1975 GT that I did a few modifications so it looks like someone shrunk a full size Camaro. Oh by the way they all have small block Chevy’s. You are not right to open your opinion against one of the coolest thing ever to roll off the GM line.

      1. Hey now, everybody’s entitled to their opinion. Also, the potential to be extensively modified (with new engines and new frames, yet) into a specialized racer, while obviously not negligible for people who like doing stuff like that, is rather far removed from a car’s virtues or faults as a stock passenger vehicle. The Henry J and the old Willys Americar also often found second lives as hot rods of various kinds.

  3. Its 2010 and we are still playing with Vegas. If you think they are extinct go check out EBAY.
    There are thousands and thousands of of these cars left and there are many of us who love them…I have 8 Vegas. two are Cosworths.
    They are fun and for alot of us 40 something year olds they bring back alot of memories.
    The important thing is this:
    What happens in Vegas,STAYS in Vegas….Ladies.

    1. Given the sheer number of Vegas built — 1.9 million or so — even a 1% survival rate would mean nearly 20,000 cars. How many of them survive in anything like original condition is another matter entirely (excepting Cosworths, where I think people have more motivation to leave them relatively unmolested).

    2. I’m looking for a Vega notchback..

      1. Hi Bob I absolutely love your 1 Millionth Vega. Is it for sale?

  4. Great history lesson and definitely one I’m adding to my Vega collection.

    My brother owned a 71 Vega which I had the occasion to drive. Liked it so much, that I decided that my first car would be a ’72 Vega GT (Turin Tan, actually more of a yellow mustard, with black hood and deck stripes, 4-speed and an AM radio.) At about 30,000 mi it had already blown the head gasket and was burning a quart of oil about every 200 miles, so I decided to rebuild the engine myself and included a few old school goodies along the way:

    Steel sleeves

    Ported and polished head with maximum size valves

    11.5 Compression High Dome Forged Pistons

    High lift Crane Cam

    Offenhauser Dual-Port Intake

    Holley 390 Carb

    Injectronic Methanol Injection

    Hooker Headers

    Weber Clutch Assembly
    …and more.

    This car has since seen an additional 60,000 mi on the road and spent a few years at the drag strip (a friend of mine at the time owned and ran a turbo/nitous Vega he called Plumbers Nightmare that ran 13s in the quarter – not too bad for a 4-cylinder in the mid-70s).

    The Vega, despite it many short comings was a fun and great handling car in its day. With the power plant upgrades I made back in 1975, its been and still is a blast to drive and will be in my collection for years to come.

  5. As an additional note about the peculuarities of the engine, another result of overheating the block was that the freestanding cylinder (unsupported at the deck)would draw down below the outer edge as the block distorted, resulting in the failure of the head gasket. Many backyarders discovered this the hard way when they tried to simply replace the failed gasket.

    Another odditiy was that the water pump was also the timing belt tensioner, which not only made timing belt replacement a headache (drain coolant, replace gasket and possibly the pump, all at the same time sliding the pump sideways to tension the belt) but resulted in the cooling fan rotating in a reverse direction of the crankshaft. This meant that the blade pitch was reverse of virtually every other fan on any other car. Attempts to improve the cooling with an aftermarket fan with more blades, deeper pitch, “flex fans”, etc. became comical. Unless the installer noted that the pitch was reversed, a scenario of “The car runs cool at idle and in slow traffic, but overheats at highway speeds” would result. The tip off was noting that air was coming out of the grille when the car was stopped at idle. As a tech, I saw this one more than once.

    Having said all that, I still liked the styling and handling of the car. One of my strongest competitors at autocrosses back in those days was a V8 powered Vega. A shame it fell victim to the corporate politics and infighting that was(is?)so prevelant at GM.

  6. It’s worth noting that whatever the quality of its execution, the Vega’s engine was ahead of its time in a lot of ways. Many modern engines are open deck, and running the water pump off the timing belt is very common. (The latter is one of those things that makes sense from a packaging and manufacturing standpoint more than the owner’s perspective, since it makes repair and belt replacement a hassle.) Both have their pros and cons, but they’re not inherently [i]problematic[/i], per se. The Vega suffered from poor execution and a sort of snowball effect of different inadequacies (like the limited cooling capacity).

  7. My mom’s first car was a 77 Monza Spyder, 305 auto,black with gold decals and red interior.
    My sisters first car was a 77 Vega GT hatch back, White with black stripes and black interior.
    They both looked and handled great, and to be honest, I don’t think there was anything out there factory that could touch the Spyder, unless it said Corvette on the side of it. My step dad was a lead footed driver and never turned down a chance to open it up on someone. So that’s where my love affair of the H-bodies came from.
    In 94 I score a cherry 76 Vega hatchback, brunt orange, with tan interior. 30K on the odometer. The car looked great with no rust. I had no care for how it ran. The Spyder was still in mom’s back yard, long abandoned and well rusted. In just a few months I had pulled the 4 banger out and using mom’s V8 Monza build up one mean little sleeper. Still sporting it’s original Orange paint, wimpy dish hubcaps at first, till I scored a set of aluminum slots. Only now powered by a hiddin mild 350, 350 turbo, with 373 posi, and riding on Spyder suspention. It looked like a plain old Vega. You had to look close to notice dual tips out the back. The muffler guy did a great job of tucking the pipes out of sight. I had a hottie in a 5.0 Mustang try to keep up with me once, only to have to wait until I stopped for gas to catch up and ask what it was, I was to pumped on whipping her ass to get her number. I parked the car in mom’s garage then robbed the motor for another project, and there it set for a few years. Met the girl I’m married to now and with a kid on the way I sold it to a cousin, with the intent to get it back. He sold it, refused to tell me to whom and it was gone. All he would tell me was that the guy was planning on cutting up a perfect Vega to make it a drag car. Why????? Ten years later a friend of mine spots an orange Vega on C.L., it was mine. The guy bought it from my cousin, towed it home and garaged it for ten years with plans that never came about. Now it’s in my garage, only a little faded. Now it’s getting another slightly built 350 only with vorted heads, Camaro world class T5 5-speed, changing to a 323 gear set, swapping to five lug axels front and back. Still plan on keeping it factory orange and already got a set of five lug aluminum slots.
    My boy’s ten, he’s seen the car in pictures and now that it’s here he thinks it’s his car. When it’s done and after he’s old enough to appreciate it. It will be. It was a part of me then and now. Hopfully it’ll be a part of him forever.

    1. AWESOME story. :D Almost makes me wish I could find a way to get my first car, a ’94 Grand Am GT back, and somehow make it fast. yeah, right…heh

  8. The Chevy Vega was one of the most popular TV game show prizes in the U.S. during its production run. The very first new car to be given away on “The Price Is Right” (Bob Barker version aired Sept. 4, 1972 on CBS) was a blue ’72 Vega Kammback wagon. It was won by a contestant who chose the correct numbers of the price (around $2,700) in the Any Number pricing game.

    Vegas were also popular “secret square” prizes on the original run of “The Hollywood Squares” (hosted by Peter Marshall with Paul Lynde in the center square) and Monty Hall gave away scores of Vegas on “Let’s Make A Deal” (considering the lousy quality of Vegas, some probably qualified as ‘zonks’).

  9. Got the 1971 in 1970 with the handling package, 4-speed, etc. I put Cyclone headers, Offy man. and the Holley 4bbl on it. Raced like a “herd of turtles” (from my girlfriend). I managed to get 80K mi. on the first engine. I got a second from a ’75 Vega that was wrecked at 500 mi. So with the ‘new’ motor, I left it stock. Mistake. They run those dead lean. The first trip of the rte 5 Grape Vine grade it ate the exhaust valves. It over-heated and required a large, full-width radiator. After it began to cut out on corners, I sold it. I have to say it was extremely comfy for my 1000 mi trip I had to take every three weeks. It was so noisy, though, at freeway speeds. Radio was useless! Had no other problems with it.

  10. Got the 1971 in 1970 with the handling package, 4-speed, etc. I put Cyclone headers, Offy man. and the Holley 4bbl on it. Raced like a “herd of turtles” (from my girlfriend). I managed to get 80K mi. on the first engine. I got a second from a ’75 Vega that was wrecked at 500 mi. So with the ‘new’ motor, I left it stock. Mistake. They run those dead lean. The first trip of the rte 5 Grape Vine grade it ate the exhaust valves. It over-heated and required a large, full-width radiator. After it began to cut out on corners, I sold it. I have to say it was extremely comfy for my 1000 mi trip I had to take every three weeks. It was so noisy, though, at freeway speeds. Radio was useless! Had no other problems with it.

  11. i had a 73 vega gt millionth and i wish i had it today i miss that car

    1. I had 3 of those over 35 years.

  12. That is a ’76 model Cosworth, the grill was changed from the ’75 model as were the taillights.

    1. Yes, if you look at the image titles (which will appear if you mouse over the photos in most browsers) identify it as a ’76, although the captions don’t really specify.

  13. My first car was a 1971 Vega coupe, Mediterranean Blue with a four speed. Dad bought it used in 1972, and by the time I got it in 1978, had already rebuilt the engine once and it was needing another rebuild at 80,000 miles or so.

    We had a second Vega (’73 GT Kammback) by this time which had been in an accident, so I swapped engines (the ’73 had steel sleeves already), and drove it all through college, getting up to 30 mpg on the highway at times. Rust around the windows was probably the biggest problem, and I got in the habit of pulling the front and rear glass out every three years to sandblast and repaint…

    By the time I traded the car in on a new Suzuki Samauri in the 1980s, it had 220,000+ miles on it and I had rebuilt or repaired every major subcomponent on the car at least once, including replacing the base trim dash with a GT trim one and dropping a Buick 3.8 liter V6 and 3 speed automatic in it. I also cut the coil springs to lower it a bit and cut the center out of the front bumper for that Camaro SS look.

    I always thought the car looked and handled great, and in hindsight, it was a great car to learn auto repair on (due to the frequent opportunities to practice). It was a great idea, poorly executed.

    Oh, the 1973 bumper was the same as the ’71-72, just with longer supports and a filler plate. I guess the thinking was to minimize sheet metal damage by moving it out a bit.

    Great article – thanks for the memory trip.


  14. I’m proud to say I owned a Vega GT, orange w/black stripes and black interior. Drove it 70,000 miles with no problems, should have bought a PowerBall ticket the same day, didn’t and also owned a Citation X11, same result, and again I did not buy a lottery ticket, damn!!!

    1. Wow — buy me one, too. ;)

  15. I love the Chevy Vega. I had a 1977 Vega, and it was my first car at 14, even though I couldn’t drive it legally yet. My step dad got it out of a trade and it needed some TLC but he let me pick out the new paint job for it and I stuck with its original baby blue color. We had a system put in it with subs and what not. I remember every day I would wash and polish it. Eventually I got my license and was able to drive it and man did I have a blast! being a girl and going to school in the two thousands with a Vega was amazing. I had that car all the way up till a few days after my 18th birthday…and then the April 27th tornado’s came into Hackleburg and completely destroyed it…bummer…

  16. My wife wanted a new car and settled on the Vega. She had and still has back problems and the seats were a good fit for her. We used it for 3 or 4 years as the family car. When we bought a new family car I started using it as a work car. By then the smoking had already started. I used it for 4 or 5 years and by that time it was using, burning or dripping a quart of oil every 250 miles or so. What brought it’s career to an end was the hinges on the lift back. I hadn’t noticed the area around them had rusted badly. I went to open the lift back, the hinges broke off the body and it knocked me down and pinned me to the driveway. That lift back is heavy because of the big piece of glass in it. I got some barn door hinges, punched holes and screwed them on with large metal screws. Lift back worked fine. Looked bad, but worked. After a while I bought a small truck and off she went to the crusher. That little car was a total piece of crap, but, It looked good and was a blast to drive. Would buy one today if the rust worms had left it alone.

  17. For someone who never owned one, & whose family never owned one, I rode in/was around several. High school algebra teacher gave me a ride in his; entering a freeway was SCARY, even for this 15-year old w/no common sense. The best mechanic in our tiny farming town refused to work on them; wouldn’t even tough one. When you mentionedd a Vega in the presence of the shop owner, he would let loose a string of profanity which would make you weak in the knees. Had a college friend who thought he was Mario Andretti; his GT left a trail of blue smoke wherever he went. Finally there was the friend of my brother-in-law who shoehorned a “built” Chevy 350 into a Vega. Seriously scary vehicle. Love your site – thanks for putting it together.

  18. Well researched and well written article. I really enjoyed it.

  19. yes the VEGA did have its problems,they are well documented ,I bought a SPIRIT of AMERICA,in September of 73.I ran it hard,showed it no mercy,my biggest problem with mine was in ate clutch cables,and loved to burn the oil.I didn’t have to change the oil ,it was always fresh ,just changed the filter every 5K miles.The engine was still going strong at 240K miles.had one cylinder that fouled a plug once a month,took it out cleaned it and good for 30 more days.I sold it in 1982,another clutch cable,snapped.after 4 of them I said good bye.It was a rust bucket by then ,the life on the tundra of central Illinois finally ,took its toll ,on the body.the transmission itself never gave me any problems,I tried to blow it but to no avail.never had to change the head gasket either,even had to start it with ETHER spray at -35 degrees a few times.Show the car a lil love they would get you from point A to point B.

  20. thanks for letting me share my experiences

  21. The cadillac HT4100 engine of the early 1980’s was also an open deck aluminum block engine with cast iron cylinder heads. Unfortunately they too also suffered many of the same problems as the Vega engine mainly the engine block warping when the engine was overheated and failed intake manifold gaskets due to different rates of thermal expansion. You would think that Cadillac would have learned from Chevrolets past experiences.

    1. I can’t say I’ve ever quite understood Cadillac’s motivation with that engine. Just about any other combination (all aluminum, iron block/aluminum heads, even a thinwall all-iron engine) would have seemed a more logical choice.

  22. Great article.lots of stuff I never knew! Had a gold 72 back in 77, burned so much oil that when I went to sell it the guy looking at it checked the oil level and it was empty,my father looked at me like I was some kind of moron. I simply told him if there was none in there,it would burn any!!! That thing never ticked or knocked,even without oil,yes,that same guy bought it!!! I’m now in the process of building a 76 v8 hatchback,yes,I do plan on keeping oil level up!!

  23. I still have a 1977 vega station wagon after 20 years nd in great condition

  24. I have had 35 Vegas over the years… Call it an illness, Just got ol #35 a few days ago. An unmolested 1976, Runs and drives with a modern day rating of 6 out of 10. Paint and minor repairs and 33 years later… Ill drive it! Some great stuff on this page! Cheers…

  25. Superb chronicle of a memorable misfit of an automobile. The Vega may have been a stinkeroo of a car, but boy, what a great drama its life story is! GM is really good at this stuff. :-)

  26. Great article, thank you very much for this. I knew that this was a very maligned car but, being a 80’s-90’s kid, I never really understood completely why.

    1. Every car with an aluminum engine had a shaky history including Porsche. 70s 911 s required rebuilding with mileage under 50k

  27. In 1977 my brother and I put enough money together to buy a Vega. Although warned by our friends that is was a lousy car, we couldnt afford a Nova and treated the Honda Civic as too small and perhaps unsafe.
    When we presented the car to our long life friend and Mechanic Cliff. He told us a special secret. Keep it clean and bring it in for a oil change ever 1500 miles. We did that and pampered the car driving it slowly thru our highway and college years. We had two breakdowns over its lifetime over and drove it for eight years until the engine finally gave up in the winter of 1984 with 93000 miles on it. Just as a afterthought, That the little vega had to push a Pontiac Firebird a mile when our friends car broke down on interstate 81 south of NY/Ontario Border. Loved it as our first car and wouldnt mind finding one just for old time sake. Brown 1977 Vega 2 door hatchback.

  28. Over the years I owned a 72 hatchback, a 73 wagon, and a brand new 74 GT Hatchback. The 72 rusted and burned a lot of oil. The 74 we got new off the showroom floor. It was fun to drive and a really good looking car. After my brother-in-law did some modifications it was a little quicker and even more fun. We got the 73 wagon as a second car and really liked both. As our family grew the vega’s went away and I pretty much forgot them. Recently I found a 72 on a farm near where I
    Live and talked the owner out of it. The car is complete with good chrome and all the windows intact. The body is in excellent condition and even the paint is still pretty good. It has the original engine and a 4 speed. It’s in my garage now and I’m preparing to turn it into a hot rod. 383 stroker motor, 9″ rear end, turbo 400 tranny, and new interior and paint job. I have always like the looks of these little cars and am looking forward to driving this for a long time. Thanks for the history of the car. I knew a few of these things, but didn’t know about all the things that happened behind the scenes. Really enjoyed the article. Thanks.

  29. With no new articles to read, I have been reading / re-reading some of your older articles. Near the beginning of the Vega article, you discuss the Corvair:

    “Unfortunately, the Corvair was expensive to build and Chevrolet initiated a last-minute cost-cutting program to bring down its list price….Later iterations, although much improved, were overshadowed by Ford’s popular far less innovative Mustang and the Corvair was left to languish, finally expiring in 1969.”

    I have never heard the Corvair compared to a Mustang – I think you meant Falcon. Is that correct?

    1. It’s correct as written — the key phrase there is “later iterations.” The second-generation Corvair was pretty much squashed by the Mustang, which took over the Corvair Monza’s role as compact sporty car.

  30. The original 140 cu. inch engine didn’t breathe very well as the intake and the exhaust were on the same side. The Cosworth solved that problem and it was a fun ride. I had a 75 and a 76. I remember being at a stop light next to some kids in a Camaro with a huge fiberglass air intake on the hood. When the light turned green I took the 76 Cosworth to red line on each throw. They almost broke their necks looking at me and wondering how I could keep even with them. I loved the sound of the engine it would just scream for more, I think the sound of the twin cam shocked other drivers more than anything else, it loved to be revved up.

    1. A lot of American engines of that era had the intake and exhaust valves next to each other, so it wasn’t necessarily terrible for breathing, although obviously a cross-flow head does have its advantages. The big issues were being saddled with early emissions gear and (on base cars) little single-throat carbs. The Cosworth obviously breathed a lot better, in part because it had something like 50% more total valve area. It was such a promising engine — it’s really too bad its development was so torturous that it ended up being a dead end.

  31. I think Chevrolet overcame the bad Corvair publicity better than the Vega bad publicity, the Vega undependability compared very poorly to Datsun and Toyota and even the hum-drum but dependable Pinto. The fender rust-thru problem was corrected, but that horrible engine had no quick fix. Think what a superb car the Vega would be if it were the beneficiary of the industrial improvement applied to execrable front-wheel drive autos.

    1. Well, the Dura-Built changes did finally resolve many of the engine’s major issues, albeit not until MY1976. It should be said that even the cast iron four Chevrolet had wanted to use would probably have suffered from the Vega’s under-specified cooling system, though — not a great place to economize! I don’t know that the Vega would have ever constituted a superb automobile, although with a better engine it would have made a decent junior Camaro. Realistically; I think it would have always suffered from the “cheap American car” syndrome.

      The negative reputations of the Vega and the Corvair were in some respects categorically different because one was reliability-related and the other safety-related. The Corvair had its mechanical foibles (some of which it took a surprisingly long time to live down after the problems were largely resolved), but its reliability wasn’t terrible all things considered; its controversy lay in the handling behavior of the early cars. The Vega, by contrast, had a pretty decent chassis, whatever the car’s reliability and durability problems.

      1. the engine was improved every year the car was in production. In 76 the cooling slots were improved in the block, a major change.

    2. You think so huh? read on my friend

      Car and Driver January 1971 awarded top pick to the Vega above the Ford Pinto, AMC Gremlin, VW Beetle, Toyota Corolla and Chrysler Simca. C&D said: “The Vega was the most expensive car in the test by almost $300 but the Vega’s virtues are nicely in proportion to its price and it was the unanimous favorite.” “The Vega pulls down the number one position because of its particular suitability to American driving conditions.

      Consumer Reports January 1971, “The Little Cars,” compared the Ford Pinto, Chevrolet Vega, AMC Gremlin, VW Super Beetle, Toyota Corona and Datsun PL510 declaring three winners—Datsun, Vega and Toyota.

      Car and Driver in a 1974 “On-the-Track Comparison Test: Twelve 1974 Showroom Stock Sedans” — Possible winners and possible losers from among the top contenders — Vega GT, Fiat 124TC, Mazda 808, Dodge Colt, Opel 1.9-Liter Sedan, Subaru 1400 GL, Datsun 710, Fiat 128, Honda Civic, Datsun 610, Datsun B-210, and Toyota Corolla 1600. In this track test of twelve top Showroom Stock contenders. the Vega GT had the quickest lap (Lime Rock Park: 1 minute, 17.4 seconds).

      Road Test October 1976, “The Great Supercoupe Shootout” — Alfa vs. Mazda vs. Lancia vs. Saab vs. Cosworth Vega “The results are in Figure 2. Read ’em and weep, all you foreign-is-better nuts, because right there at the top, and by a long way at that, is the Cosworth Vega. It had the fastest 0-60 time, the fastest quarter-mile time, and tied with the Saab for the shortest braking distance”.


  32. In 1980 my future wife had a 1975 Vega Estate with all the bells & whistles when we first met. It was a low mileage ( less than 40,00 ) car but I soon found out that it would break down no the average of once a week, mostly due to that engine. The exhaust manifold cracked & fell apart and I was forced to go to aftermarket headers as you could not find a good one in the salvage yards or even buy one through GM. One time she called me from the next town over to say the car wouldn’t start and when I looked at it I found all of the bellhousing bolts backed out and a one inch gap between the engine & transmission. The car its self was grossly underpowered. A on long grade hill we would have to climb regularly I would hit it 75mph going down one side and when I made up the other I would be doing maybe 45.

    later on I bought a 1979 Buick Skyhawk hatchback, same basic body as the Vega but with a much nicer interior and it had the 3.8 V6 and it turned out to be a great little car getting mid 20’s milage and would get rubber in all three gears with an automatic. It ran strong until it was totaled at 135,000 in a winter related accident.

    1. Which transmission did it have? The Vega’s feeling of being underpowered had a lot to do with the economy-oriented gearing — a 2.53:1 axle is not going to make a none-too-powerful engine happy going up grades.

      1. The 2.53 axle came with the 3 speed manual the auto came with the 2.92 or optional 3.36 axle

      2. The economy 2.53 axle was not available with the auto trans if you had read any of the vega road tests in the day. You would know the Vega was the only small car recommended with auto transmission because of the good torque of the 2300 engine and 2.92 or 3.36 axle ratios.

        1. I have indeed read the Vega road tests of the day. My previous remark was an off-the-cuff response to a comment, so I didn’t go delving back into my notes of six years earlier for axle availability chart, although I will bow to your knowledge in that regard. I will note that “performance” (good or bad) is a subjective quantity and depends a lot on what you’re comparing it to.

  33. My grandfather bought a new 72 Vega Kammback wagen on my recommendation (I was a well read 11 year-old car nut) having read all the car mags monthly for through my teen years. He got good service with none of the rust problems and the engine ran fine until it reached over 100k when it started using oil. New valve seals would have cured that but he just drove it without care. I was heartbroken to find it gone a few years later but he surprised my with a one year old midnight blue 74 GT hatchback. I bought my first Vega three years later at 17- a four year old GT Millionth edition. Today I own a GT Millionth 4 speed, a Cosworth 5 speed both under 10k miles and a 71 Panel Express 3 speed with 76k miles

    1. I don’t think anyone would argue that the Vega was without virtue — in handling and looks, it needed no apologies, and when properly optioned it performed pretty well. It’s easy to see, for instance, why a contemporary buyer would have taken a Vega over the dumpy-looking Pinto or a dowdy Toyota Corona on looks and performance. (And of course most contemporary Japanese cars were no prizes with regard to rust resistance.)

      1. I do believe GM made a mistake not using the cast iron 4. GM engineers wanted an all new engine for this car and wanted to show off their linerless engine-block technology. They used the wrong car to do it. They should have used the new technology on a limited production model. Not on 2 million plus economy cars.

        1. Definitely! Interestingly, GM had previously considered using a similar process for the aborted Cadillac V-12 engine a few years earlier. I don’t know that it would have worked any better there, but something like that would have been a wiser place to start: lower and slower production, less price sensitivity, different customer-dealer relationships.

          The benefits of using that technology in the Vega are harder to see. Although omitting the liners was cheaper, I’m not sure it offset the higher cost of the block itself and while there was some weight savings versus cast iron, I don’t think it was that great.

          Had Chevrolet engineers been left to their own devices, they probably wouldn’t have used the existing Chevy II four. They had plans for an all-new cast iron engine that would likely have been more compact and a bit lighter than the Chevy II engine. It would probably have been somewhat heavier than the Vega engine, but probably not dramatically so — Detroit had gotten quite good at thinwall casting of iron blocks by then. An extra 50 or 60 pounds upfront would not have been a terrible trade-off, all things considered.

          1. While Chevy was finalizing the GM 2300 engine they designed a Hemi aluminum head for the engine that was installed in the XP-898 Vega-based concept car. Numerous prototypes were built, and manufacturing tooling was started in anticipation of approval for production. The real story never came out, but some combination of corporate politics (“You don’t need another cylinder head – mine will work just fine”) and additional program investment killed the program.

            Check out my website http://chevyvega.wikia.com/wiki/Chevrolet_Vega#Stillborn_engines

  34. My 71 Vega 3 speed 2.53 axle has decent performance and gets 30 mpg

  35. My panel and millionth edition are pictured in this article

  36. I bought a 1971 Vega GT back in 72′ for $1500-it was very low mileage and like new. Chevy replace the front fenders for free after holes appeared on the tops. After about 40K miles, the engine began using a LOT of oil. At the time I had no idea why. A local repair shop said it needed rebuilt and explained the sleeveless aluminum block to me. The expense of having the block sleeved and rebuilt was way more than the car was worth. In 1974 I traded it in on a new Z28….which I still have. Although the Vega had a lot of shortcomings, it handled extremely well-and got reasonable gas mileage. I was a teenager at the time and was very hard on that little car. So I would imagine if it was driven as it should have been, it would have held up much better. This article was a wonderful trip down memory lane!

  37. I can’t help but think that if Chevy had been allowed to develop their own 4cyl engine for the Vega, they probably would have taken design ideas from the Pontiac 195 Slant 4, the Buick aluminum 215 V8, the Chevy ZL1 427 aluminum V8, and the small block chevy and combined them into one all aluminum slant 4 engine that was ½ of a 350 cid small block chevy. If introduced in the 1971 Vega, this all aluminum slant 4 engine would have displaced 175 cid, weighed in at about 265 lbs, and been rated at 135 gross HP @ 4,800 rpm (105 net HP @ 4,400 rpm) and 180 gross ft-lbs @ 3,200 rpm (150 net ft-lbs @ 2,800 rpm). These engine power figures were calculated as one half of the advertised output of the 1971 L48 350 engine. In order to keep the design as low a risk as possible, I think they would have gone with cylinder liners like the ZL1 427 and the Buick 215. If Chevy wanted less displacement, they could have also gone with ½ a 307 V8 or even ½ of a 283 V8.

    This slant 4 engine design offers the following advantages over the actual production 1971 140 cid Vega engine:

    o Leverages existing SBC low risk design
    o Lighter than 140 cid Vega 4cyl engine
    o Not as tall as 140 cid Vega 4cyl engine
    o Better center of gravity than top heavy Vega engine
    o More powerful than Vega 4cyl engine
    o Cheaper to manufacture than Vega 4cyl engine
    o Many parts in common with SBC; exploits Chevy parts bin
    o Provides low cost production aluminum heads for all SBC V8 engines
    o No timing belt
    o No new untried/high risk technologies

    I admire Ed Cole for the excellent design work he did on the Cadillac and Chevy V8 engines; however after 1957, it would have been better for GM if he had left and gone to work for Ford in my opinion. His “innovative ideas” exploiting “cutting edge technologies” in regards to the Corvair, Vega, and GM Wankel projects helped to destroy Chevy and GM’s profitability, reputation, and market share in my humble opinion. Your mileage may vary.

    1. John,

      I don’t have much in the way of detail about the engine Chevrolet DID design for the Vega, but DeLorean indicated that it was cast iron, not aluminum, about which a lot of GM divisions were still not that keen except for special purposes. (The ZL1 was obviously not intended for mass consumption and the aluminum Buick engine was seen as costly and very troublesome, which is why GM largely abandoned it.) If it had been entirely up to Estes and later DeLorean and their engineers, I doubt they would have opted for an aluminum engine for a small car like this, which was very price-sensitive. I also don’t think they would have considered an all-aluminum engine low-risk. Lower risk, perhaps, but still troublesome and a needless extravagance for general passenger car duty.

      My understanding is that Chevrolet’s existing 2.5-liter four, still notionally available in the Chevy II/Nova at that point, was in many respects an inline four-cylinder version of the SBC — in essence, “Let’s take one cylinder of the V-8 and arrange four of them in a row” — and shared a variety of parts. The dilemma was that the commonality made the 2.5-liter four fairly large, physically, which wasn’t ideal for a subcompact car.

      Regarding the slant-four idea, it’s an interesting concept, but I think it’s important to keep in mind that the Pontiac engine was not all that much lighter than a 389 — it was not half a 389 in that sense so much as a 389 with one cylinder bank lopped off above the crankcase. My very rough back-of-the-napkin guess would be that doing the same with a 350 SBC would be something in the realm of 460–480 pounds without flywheel. Casting the remainder in aluminum (which is not as simple or cheap in a manufacturing sense as it appears you’re assuming) might bring that down to perhaps 375 pounds. These are the sorts of calculations that make corporate VPs say, “Look, wouldn’t it make more sense to just use the six?” I also don’t know that either Estes or DeLorean would have been terribly eager to revisit the big slant-four concept, which at Pontiac had been expedient, but also a rather rough and uncouth piece of work.

      If Chevrolet had been left to their own devices, and assuming they had opted for a clean-sheet engine, my guess is that it would have ended up being a somewhat smaller but very conventional cast iron OHV four, something perhaps along the lines of the Volvo B18/B20 engine. It would probably have ended up in the same ballpark as the Vega engine in terms of displacement and power, although it’s conceivable Chevrolet would have offered a smaller-displacement base engine for the economy-minded (which would likely have had the virtue of also being smoother — for inline fours without balance shafts, more than 2 liters starts getting buzzy and rough in a hurry). This is speculative, mind you; if I find some more concrete info on what Chevrolet may have planned, I’ll let you all know.

    2. (Also, comments are moderated to spare you all the cavalcades of spam I periodically get, so there’s no need to repost if your comment doesn’t immediately appear. Unless it happens to post while I’m already doing some maintenance or updating task, the way it works is that I get an email notification and then have to log in when I’m next able so I can approve the comment or not.)

  38. [quote]”the Pontiac engine was not all that much lighter than a 389 — it was not half a 389 in that sense so much as a 389 with one cylinder bank lopped off above the crankcase. My very rough back-of-the-napkin guess would be that doing the same with a 350 SBC would be something in the realm of 460–480 pounds without flywheel.”

    The weight of the Pontiac 195cid 4cyl was 479 lbs. The weight of the 389 V8 was 680 lbs. So I used 0.70 times a 350’s weight of 530 lbs which gives 370 lbs for an iron 175 cid slant 4. As far as weight savings going from iron to aluminum I used the ZL-1’s ratio of .75 which gets the weight of an all aluminum 175cid slant 4cyl down to around 278 lbs. With a few clever design details here and there, the engine could possibly end up even lighter.

    As far as using an all aluminum engine versus an all iron engine, it looks like GM had decided that the weight savings gained by going to an aluminum block to increase gas mileage and handling benefits was worth the extra cost and trouble. Also, it was used as an advertising selling point to make the Vega look more exotic. Lined aluminum engines were a mature and accepted technology by 1971 (much more so than 1961), but liner-less, no so much.

    Liner-less aluminum blocks were the new state of the art in CAN-AM racing big blocks where cylinder wear and 100,000 miles between rebuilds was not an issue. It was definitely an immature technology at that point for passenger car use. Note that GM’s current production LSX and LTX small blocks still use liners today.

    Also, an aluminum version of the small block chevy aluminum head would be far cheaper to manufacture than the Vega iron overhead cam head. There would be virtually no development costs and the head could be used on about 2,000,000 engines a year (4cyl and V8) which would have greatly helped to amortize the cost of switching to aluminum. Aluminum heads for the rest of Chevy’s car V8s would have helped increase gas mileage across the fleet which would have come in handy in 1974 and 1979. Just my humble opinion.

    1. Comparing engine weights is tricky business because you end up with a lot of contradictory figures, none of which is necessarily actually wrong. The basic problem is that many sources don’t clearly specify whether they’re talking about the engine with or without accessories and with or without flywheel. (I don’t say this as any kind of “gotcha” at you — this is an issue I run into fairly regularly.) The 530-ish lb figure for the SBC is, at least according to sources that do specify what condition they mean, for a complete engine with accessories, but without flywheel. The 680 lb figure you quote for the 389 is with accessories and flywheel; without flywheel, it’s more like 620–625 lb while the 326 is a bit under 600 lb. As for the Slant Four, there are various quoted figured ranging from the 479 lb you mention to 557 lb, the most common number being 507 lb. (My guess is that the figure you cited is for a bare engine, 507 lb is probably dressed with accessories, but no flywheel.)

      From a methodological standpoint, I have a lot of reservations about the “deduct a percentage” approach because I think it can easily give a misleading impression of the weight savings involved. With a slant-four engine of this sort, all you’re really saving is the weight of one cylinder head and part of the bare block, so I think 30% is probably over-generous. (Aluminum/iron comparisons are even more complex because a lot really depends on architecture and wall thickness, but I think 278 lb is already a lowball figure for the kind of engine you’re describing.)

      All that aside, while this is an interesting exercise, I doubt it bears any resemblance to what Chevrolet had in mind at the time. By the late ’60s, thinwall iron casting techniques had gotten pretty good and making a 2.0–2.5-liter cast iron four in the realm of 350 lb wasn’t a great stretch. Even if they could have saved 70 lb (not a shabby figure) with aluminum, I think Chevrolet engineers would have (and probably did) question whether that was worth the extra cost and manufacturing headaches, especially for a car in this price class. John DeLorean, who was general manager of Chevrolet during most of the Vega’s production development, said specifically that Chevrolet’s plans were for a cast iron engine.

      As for what “GM” thought, it’s critically important to remember when talking about GM products of this era or earlier that there was no singular voice. There were the individual divisions’ engineering departments (which in Chevrolet’s case was quite large), the division managers, the supplier divisions (e.g., Fisher Body or Hydra-Matic), the corporate Engineering Staff, and upper corporate management, which were operationally separate and not necessarily on the same chapter, much less the same page. In general, the divisions’ priorities were, “Will it help us sell cars?”; senior management’s priority was, “Will it make usefully more money than it costs?” (which sounds like “will it sell,” but isn’t the same thing); and the corporate engineers’ priority was, “Is it a technologically feasible idea with potential commercial applications?” The corporate engineering teams had been working on various aluminum engines since at least the early ’50s and I assume were pretty keen on them.

      The divisions, who were the ones in the position of paying for the tooling and material and making the engines work in production, were notably less so, and I suspect by the late ’60s a fair number of the division managers would have pointed to the aluminum 215 as Exhibit A for why it was more hassle than it was worth. I think it’s noteworthy that between MY1965 and the debut of the Vega, the ONLY aluminum engines any GM division offered in production were the Corvair and the ZL-1 — which was only a production engine in the more generous sense of the word. The divisions’ advanced engineers played around with aluminum blocks and heads, but even Cadillac didn’t bother going any further. Obviously, it’s true that Chevrolet tried to make advertising hay of the Vega’s advanced aluminum block, but that was trying to make a silk purse out of a sow’s ear foisted on them by corporate at the behest of Ed Cole.

      While there are obvious benefits to lighter aluminum engines — there’s a reason most modern fours are all-aluminum — as a fuel-saving tactic, it’s kind of an expensive way to go. Yes, it helps, but saving 70 lb or so is only going to do so much for 4,000 lb cars powered by engines of 5+ liters that are festooned with primitive early emissions control devices. Which brings me back to my original point that a 2.9-liter four seems an odd choice for an economy car, aside from the likelihood of it vibrating occupants’ fillings out of their teeth without balance shafts. It’s the Gremlin problem: the AMC six was a pretty stout engine, as its longevity indicates, but 3.8+ liters does not an econobox make. An early investment in aluminum engine technology would have been worthwhile, but Chevrolet (and GM in general) also really needed some stalwart, reliable, reasonably pleasant smaller engines to complement the familiar SBC and big six, and they could probably have done a better job with that in iron.

      1. [quote]”Comparing engine weights is tricky business because you end up with a lot of contradictory figures, none of which is necessarily actually wrong. The basic problem is that many sources don’t clearly specify whether they’re talking about the engine with or without accessories and with or without flywheel.”

        I can agree with that. Just as an aside, I was looking through a July 1972 Hot Rod Magazine article where they report on a Chevrolet Engineering 1972 Vega fitted with an all aluminum 302 V8. They list the weight of an iron SBC at 535 lbs and the weight of the aluminum 302 as 375 lbs. So if one used a ratio of .75 for slant 4 weight/V8 weight, this would yield 281 lbs for an all aluminum slant four based upon the SBC.

        [quote]”With a slant-four engine of this sort, all you’re really saving is the weight of one cylinder head and part of the bare block, so I think 30% is probably over-generous.”

        Well that minus 4 connecting rods, 4 pistons with rings, 4 piston pins, 8 lifters, 8 push rods, 16 head bolts, a head gasket, a valve cover, 1/2 an intake manifold, and one complete cast iron exhaust manifold. Every little bit adds up.

        [quote]”John DeLorean, who was general manager of Chevrolet during most of the Vega’s production development, said specifically that Chevrolet’s plans were for a cast iron engine.”

        Ok, I give up. Chevy probably would have gone with their cast iron 153 cid I4 then. How boring. Somehow I have trouble believing that the man behind Pontiac’s OHC conversion of the Chevy inline 6 cyl would have left it at that.

        [quote]”The divisions, who were the ones in the position of paying for the tooling and material and making the engines work in production, were notably less so, and I suspect by the late ’60s a fair number of the division managers would have pointed to the aluminum 215 as Exhibit A for why it was more hassle than it was worth.”

        Yes, the 215 Buick was a hassle using 1961 era Detroit technology and the low production numbers. Rover didn’t seem to have too much trouble making the engine though a few years later. By 1971 the technology had progressed quite a bit, partly because of GM’s Buick 215 that helped to develop the required processes. This has always been one of GM’s biggest problems in my opinion. GM spends untold millions pioneering, developing, and bringing to market new technologies and after about 10 years, just as they get all the bugs worked out, they kill it. About the time they kill it is just about the time they should have doubled down on it and mass produced the crap out it since it is now a mature, perfected, and workable technology with all of the tooling and development costs amortized.

        [quote]”I think it’s noteworthy that between MY1965 and the debut of the Vega, the ONLY aluminum engines any GM division offered in production were the Corvair and the ZL-1 — which was only a production engine in the more generous sense of the word.”

        This brings me to my second point. All of this exotic stuff like the all aluminum Buick 215 and the ZL1 427 become way cheaper and far less exotic if you produce the crap out of it. I really can’t believe that Chevy built 100 or less ZL1 engines in 1969 and then were surprised that they cost $4,000 each to make. This should have been a surprise to no one. The more you make, the cheaper they get.

        If you want an affordable all aluminum engine for the Corvette and Camaro, then make all 2,000,000+ of your passenger car engines out of aluminum. GM has had a bad habit IMO of limiting certain options to only a hand full of cars on one model line, when the technology should have been exploited company wide on all model lines in order to reduce the development and tooling costs. I think Zora Duntov probably tried to get that point across.

        [quote]”While there are obvious benefits to lighter aluminum engines as a fuel-saving tactic, it’s kind of an expensive way to go. Yes, it helps, but saving 70 lb or so is only going to do so much for 4,000 lb cars powered by engines of 5+ liters that are festooned with primitive early emissions control devices.”

        Well, only if that’s the only thing you do. However it is merely one of many weight saving tactics. That’s why Chevy went to an aluminum case Powerglide in ’62, an aluminum alternator in ’63, all aluminum carburetors, aluminum brake drums, the lighter duty smaller ring gear 10 bolt rear axles and smaller brakes in the 1970-80s, aluminum intake manifolds, smaller lighter A/C compressors, plastic dashes and interior trim, thinner sheet metal,..etc. Every little bit adds up.

        1. Regarding the weight savings and the additional pistons/con rods/etc., that’s a good point. Still, if we assume 507 lb for Tempest four sans flywheel and 625-ish lb for the 389 sans flywheel, the savings there is a little less than 20%.

          DeLorean indicated that Chevrolet had plans for a new cast iron four. (So was Pontiac around that time, interestingly.) So, I don’t think they would have just used the Chevy II engine — I assume the goal would have been to make something physically smaller, a little lighter, and a bit more modern. I suspect DeLorean himself would have been happy to apply a Pontiac-style OHC head, giving something loosely comparable to the Ford OHC Pinto/Lima four, although getting the corporation to be willing to pay for it was quite another matter, since they’d just axed it for Pontiac. I recognize that “What they should have done” is a more fun game than “What they would have done,” but that was kind of the situation.

          The ZL-1 is really a curve ball in this kind of discussion because it was functionally a racing engine (as were the L-88 on which it was based and the conceptually comparable Pontiac “Super Duty” 421 engines of the early ’60s) from a division and a corporation that were trying hard to maintain the pretense of not being involved in That Sort of Thing. It wasn’t intended as a prototype for some future mass-market engine, nor would it have been desirable as one, and I don’t think anyone involved was surprised or particularly concerned about the unit cost except in the most token sense. In that, it was more like Ford’s OHC 427, which even if it had been a regular production option would likely have been sold only in whatever limited quantity it would have taken to homologate it. Nobody had any illusions that it was going to pave the way for OHC Country Squires.

          In terms of technology, again, it’s important to remember that the divisions in this era still did their own thing beyond sharing the common body shells. It wasn’t that “GM” limited particular technologies or innovations to a specific model or division (although in most cases there was a rule that the division that came up with something got a year of exclusivity); it was that each division was responsible for its own P&L. If Buick, for instance, had seen the Olds F-85 Jetfire and decided to do a turbocharged Skylark, they would either have had to do their own development and testing, pay for their own tooling, and make their own deals with outside suppliers or else buy the hardware from Oldsmobile at a markup, which seems to have been economically unattractive except where likely sales volume was too low to justify the tooling expense (as with Olds buying the Buick V-6 for a while) or where senior management said they had to do it (as with Pontiac using the Buick 215 in the Tempest). Obviously, for certain components, like some transmissions, it ended up making sense for a supplier division to build it and the other automotive divisions to buy it — I assume in those cases, that enabled the supplier division to offer a more competitive unit price than individual divisions could have matched.

          Also, as I’ve talked about with regard to cars like the Oldsmobile Toronado, a lot of GM’s more innovative ideas in this period, at least the ones that made it to production, were the result of specific engineers and executives pushing really hard for them and, not infrequently, accepting a variety of compromises along the way. (The Toronado was not the application the Oldsmobile engineers interested in FWD were thinking of, for obvious reasons.) Where “GM” as a whole comes into the picture is (a) that the corporation, which had to sign off on expenditures, were often reluctant to pay for stuff unless it was absolutely necessary or had clear sales potential and (b) the bright young folks who’d come up with and champion the cool stuff would then get promoted and move to a different division, often leaving the fruits of their labors to successors who either weren’t interested or had their own pet projects to advance. So, the people who originally said, “Let’s do this neat thing as a testbed for future family cars” and reluctantly accepted some more limited or compromised application as a starting point, often weren’t around a few years later to say, “Okay, we’ve proved that FWD works, now why don’t we create a FWD Vista Cruiser to really take advantage of the space-saving potential?” (or whatever).

          It’s often the case that the leaders in a particular industry become rather hidebound conceptually. A lot of the most novel products and ideas tend to come from mid-level players who’ve been successful enough to have some money to spend and want to build on their momentum. Once you’re No. 1, you may end up having a lot more to lose than to gain — particularly at a giant like GM, whose senior management was deathly afraid of being forcibly broken up or otherwise being pilloried by the feds — and any change you make on any substantial scale is going to cost you a bundle, which makes all your senior finance people very touchy about making sure the expenditure is absolutely necessary. I’m not justifying that mentality, which I think is often regrettable and whose political ramifications are frequently ugly, but that’s how these situations come about.

          1. “Okay, we’ve proved that FWD works, now why don’t we create a FWD Vista Cruiser to really take advantage of the space-saving potential?”

            They did something better than that, the GMC Motorhome.

          2. Well, “better” is arguable. The GMC Motorhome (which is covered in the second part of the Toronado article, if anybody missed it) was a neat thing, but it was also enormous and very, very expensive, so it was not a solution for an affluent middle-class family that just wanted a station wagon with good snow traction.

  39. [quote]”I suspect DeLorean himself would have been happy to apply a Pontiac-style OHC head, giving something loosely comparable to the Ford OHC Pinto/Lima four, although getting the corporation to be willing to pay for it was quite another matter, since they’d just axed it for Pontiac.”

    The ironic thing is that, in real life, GM and Ed Cole forced DeLorean to make an all new 4cyl engine with an OHC head.

    I wonder if DeLorean enjoyed any sense of vindication about that.

    [quote]” The ZL-1 is really a curve ball in this kind of discussion because it was functionally a racing engine (as were the L-88 on which it was based and the conceptually comparable Pontiac “Super Duty” 421 engines of the early ’60s) from a division and a corporation that were trying hard to maintain the pretense of not being involved in That Sort of Thing. It wasn’t intended as a prototype for some future mass-market engine, nor would it have been desirable as one….”

    When I talk about the ZL1 engine, I’m using it in a general sense. The general sense that it represents an all-aluminum V8 with cylinder liners. I certainly agree that Chevy would not want to produce 2,000,000 ZL1 racing engines a year, but they could produce 2,000,000 all aluminum engines a year, and this would greatly reduce the cost of a one-off competition engine like the ZL1. After all, who wouldn’t want an affordable 396, 427, or 454 in their car that weighed the same as an iron 327?

    [quote]…”and I don’t think anyone involved was surprised or particularly concerned about the unit cost except in the most token sense.”

    I think Vince Piggins and the dealers who ordered a COPO ZL1 Camaro were pretty surprised at the price tag. I don’t think they were mentally prepared for “One Camaro for the price of Three” when they hatched the idea for a ZL1 Camaro to compete in AHRA Super Stock competition. For the life of me, I’ll never understand why they didn’t make limited COPO production runs of L88 Nova’s in ’68 and ’69 instead. They would have been far cheaper and been raced in larger numbers as a result.

    [quote] ”In terms of technology, again, it’s important to remember that the divisions in this era still did their own thing beyond sharing the common body shells. It wasn’t that “GM” limited particular technologies or innovations to a specific model or division (although in most cases there was a rule that the division that came up with something got a year of exclusivity); it was that each division was responsible for its own P&L.”

    Agreed. I misspoke. I really meant companywide across Chevrolet, and not necessarily GM wide. And this leads me to one area where I believe GM sometimes unfairly hurt Chevy’s profitability. Chevy, as the lowest priced car division of GM, wasn’t really able to take much profit on each car to start with. Afterall, their prices had to compete with Dodge, Plymouth, Ford, AMC, and even VW to some degree. Then GM saddles Chevy with developing all sorts of new expensive technologies (e.g. the liner-less Vega block and Vega OHC head) and it really starts to eat into Chevy’s profit per car.

    In a perfect world, Cadillac and/or Buick would be innovating the expensive technology since they have higher mark ups per car. Then once Cadillac and/or Buick have sold it for a few years on a low volume basis and all of the bugs are worked out, it can be trickled down to Chevy and Pontiac so that they can mass produce the crap out of it. Which is by and large the way it seemed to work at GM until the mid-1950’s. But I guess Chevrolet had the “misfortune” of having such a talented engineering staff. I’m sure that none of that engineering talent resulted from Chevy’s “non-racing” program which Buick and Cadillac didn’t have [said with tongue firmly in cheek].

    [quote] “(b) the bright young folks who’d come up with and champion the cool stuff would then get promoted and move to a different division, often leaving the fruits of their labors to successors who either weren’t interested or had their own pet projects to advance.”

    Agreed. I think this was responsible for a lot of false starts, and the cancelation of many higher tech projects just as they were getting to the point where they could start bearing some fruit. This is one of the inherent drawbacks of any large bureaucracy.

    1. I definitely agree that foisting an OHC engine Chevrolet didn’t want on DeLorean shortly after axing one at Pontiac that he did is highly ironic. Even more ironic, although obviously speculation on my part, is that I have the strong impression that had Chevrolet suggested an all-new OHC engine, they would have faced management resistance on cost grounds. (Talk about “Do as we say, not as we do.”)

      The other consideration with the ZL-1 (and L-88) is that because it was basically a racing engine, it got into a variety of other touchy political and policy territory that had nothing to do with manufacturing. It was a type of engine whose existence represented at best a liberal interpretation of the “no racing, we mean it” policy and the corporation’s (as opposed to the divisions’) concern about maintaining some kind of sense of decorum in the face of a real and often very contentious public debate about safety and emissions, in which GM was wearing an enormous bull’s eye. So, as an example of corporate philosophy or policy or what have you, it’s a bit like talking about the typical Roman emperor based on one of those guys who were deposed or assassinated after ruling for 90 days. On one hand, it’s very revealing, but on the other, it doesn’t entirely make sense except in (rather complex) context.

      I think the “trickle-down technology” idea of GM is a popular impression that’s not borne out by the historical reality. It was really more of a juggling act. The corporate Engineering Staff was there to work on long-lead ideas so the divisions didn’t burn all their money on R&D, but each division also did its own R&D, I think because Sloan wisely didn’t want to delegate so much to the corporate staff that the production divisions would be unable (or not allowed) to come up with their own innovations. The divisions would occasionally poach stuff from each other, in part a function of engineers moving from one to another. (The Tri-Power carburetor setup began at Oldsmobile, not Pontiac, for instance.) Some divisions’ chief engineers would resist certain inventions out of personal prejudice or the feeling that it didn’t suit their needs. Occasionally — though not all that often, so far as I can tell — senior management would force certain divisions to share something, which seems to have engendered a fair amount of resentment. The divisions were competitors and certainly independent-minded, if not entirely independent operationally. In retrospect, it’s easy to think that silly or wasteful, but it made GM a lot of money and it enabled the divisions to establish their own niches rather than relying on some central corporate brand manager to dictate who was supposed to be what. (And obviously Chevrolet Engineering didn’t have any monopoly on performance-minded engineers — even Buick had some, although in this period I think a lot of the stuff came out of their West Coast technical training center.)

      That also affected the logic about commonality. Since the divisions mostly had their own engines, for instance, there was less to be saved by commonality beyond a particular division. It might help a little in the sense of having more engineers and manufacturing people on staff (some of them moving around between divisions as they advanced) with knowledge of machining aluminum or what have you, but if, say, Buick had adopted aluminum cylinder heads for all its engines, that wouldn’t make it any cheaper for Chevrolet or Pontiac to do the same. Chevrolet and Pontiac had their own engine plants and had to pay for their own tooling and manufacturing development out of their own budgets. Of course, senior management eventually did push for more cross-division commonality and even corporate engines, which ended up having a variety of negative effects on all concerned. DeLorean complained bitterly that it cut into Chevrolet’s margins, but it also had the effect of cheapening the pricier cars. (One could argue that at least in the ’70s, the big winner ended up being Oldsmobile, which arguably found the sweet spot between cost, price, and prestige value.)

      1. I would add that where there are opportunities for substantial commonalities of scale, whether cross-divisionally or in a single large division like Chevrolet, the larger volume actually seems to be a significant deterrent to making stuff too sophisticated or too fancy. The situation ends up like this: One person says, “Hey, if we standardize [for instance] aluminum brake drums across all our million-unit annual production, we can bring the extra cost down to only $2 per car,” and then the finance people tear out their hair and cry, “But that will cost us an extra $2 million a year that we don’t have to spend!” Then of course there’s the joker who chimes in with, “You know, if we reduce the size of all our standard iron brake drums by a half inch, we can save 25 cents per car, and that’s a quarter of a million dollars a year.” The boss likes the sound of that, so that guy gets a very nice bonus and the first person is told, “Sorry, Joe — we love your idea, but it’s just not cost-effective.”

        You see this happening a lot today: The more successful a product becomes, the more it ends up getting cheapened to pump that little bit more fat into the margins. That’s not always the case, but it’s very common and businesses clearly incentivize that kind of thinking.

  40. [quote]”I would add that where there are opportunities for substantial commonalities of scale, whether cross-divisionally or in a single large division like Chevrolet, the larger volume actually seems to be a significant deterrent to making stuff too sophisticated or too fancy.”

    Well, it should have been, but that didn’t stop the over-engineered Corvair and Vega. Here I think, Ed Cole’s persuasive persona and impeccable engineering record were able to overcome most anything standing in his way. Ed was a consummate engineer and loved a good engineering challenge but seemed, in later years anyway, to go just one bridge too far when it came to producing “engineering state of the art” automobiles.

    GM and Chevy had a deep talent pool of truly legendary car guys in those days. Guys like Harley Earl, Ed Cole, Zora Duntov, Harry Barr, Dick Keinath, Bill Mitchell, Vince Piggins, Bunkie Knudsen, Pete Estes, John Delorean…etc. I must admit that my favorite Division General Manager is Bunkie Knudsen, my least favorite is John Delorean. Bunkie turned Pontiac around and made them the car to beat in NASCAR in the early 1960’s, and really put Chevy street performance on the map in the mid 1960’s. Bunkie went on the help Ford street performance out a ton in the short time he was there, but Ford couldn’t understand the brilliance of a man like Bunkie and fired him. One of my favorite Bunkie idioms was “Sell what you race, and race what you sell”.

    1. As far as cars like the Vega and the early Corvair go, a related problem is that over-engineering (or, perhaps more precisely, over-ambitious engineering) often contributed to the impulse to cheap out in other areas. The early Corvair’s front anti-roll bar is perhaps the most notorious single example, but there was a lot of that with the Vega as well.

      I think the fundamental problem, which certainly wasn’t limited to GM or even the auto industry, is not lack of talent or vision, but rather that big modern corporations, especially ones that operate on what’s now called a profit center basis, end up incentivizing a lot of dysfunctional behavior. The corporation as a fictive legal ‘person’ has sort of an internal ecosystem that has to be maintained and cultivated to keep the whole thing healthy, but manager performance is measured in ways that frequently end up rewarding one department or division for undermining another. It’s like a forest hiring its own loggers and giving them bonuses for unsustainable cutting without replanting.

  41. [quote]”I recognize that “What they should have done” is a more fun game than “What they would have done,”….”

    Certainly, which is why I like the all aluminum, 1/2 a 350, slant 4 concept. It’s a hot rodder’s dream. All it takes to hop it up is to drag the engine through the Chevy LT1/Z28 parts bin (11:1 forged pistons, Z28 forged pink rods, LT1/Z28 cam and valve springs,..etc.).

    Everyone would immediately know how to modify it for more power, because all of the small block Chevy tricks would work on it. Because of the Chevy investment in an aluminum head for this engine, Chevy would no doubt make a version with larger ports and valves (2.02in and 1.60 ex) for the Corvette and Camaro LT1 and Z28 engines, as well as, HD over the counter parts sales. This big valve head could then, in turn, be used on the Vega engine to extract more power. Chevy might even get into the game and offer a production Z29 Vega instead of the GT and Cosworth models.

    After a few years, I think, the lined aluminum block would then find its way into a production V8 version for the rest of Chevy’s car models when the energy crisis hit. It’s a win, win, win. This is the sort of parts bin engineering that Vince Piggins and Zora Duntov would have come up with if they had been tasked with the Vega engine IMO. But alas, this is far too practical an approach for some. Especially those who don’t grasp the benefits of product promotion through owning street performance.

    1. A 2.9-liter slant four based on the 350 would be easy to hot-rod, but I maintain that it wouldn’t have been terribly desirable as an economy car engine, that being nominally the point of the exercise. Even 2.2 or 2.3-liter fours get awfully buzzy without balance shafts, and above 2.5 liters their civility gets pretty threadbare; the Pontiac slant four had that problem, particularly with a manual transmission. They also get thirsty, especially with late ’60s/early ’70s hardware, and in aluminum with cylinder liners wouldn’t be cheap.

      I’m aware that the Vega’s rehabilitation in the eyes of enthusiasts, such as it’s been, has been based mainly on the possibility of making it into a hot rod, as was the fate of many a Henry J. However, that wasn’t what the Vega was designed for or what most people bought it for. It was supposed to be an inexpensive compact car for people who wanted something a little cheaper and better on gas and insurance than a Nova or a Duster, customers who might otherwise consider something like a Pinto, a Toyota Corona, or maybe a stripped Maverick. For that duty, the Vega engine really didn’t do badly in terms of power or economy — the issue was that it was troublesome. I think the large majority of buyers would have been better served by something similar in displacement and power, but with a cheaper, more dependable iron block and some of the money saved on not having the aluminum engine put back into the various corners that were cut to keep the original list price down.

      I like compact coupes and the Vega obviously wasn’t a bad foundation for a sporty car — it was attractive, it handled well, etc. But I think about what a huge slant four without balance shafts would be like in a vintage compact and my reaction is, “Maybe it has power, but who wants to use it?” I had the same feeling about the much later Quad 4, and that was only 2.3 liters…

  42. As far as the engine vibration goes, that’s a fair point. Although I’m not sure how much worse it would have been than the actual Vega 140 cid that was produced. People who bought cheap Chevy compacts/sub-compacts back in those days weren’t really that concerned with NVH anyway. I mean, it’s not like we are talking about a Porsche, BMW, or Ferrari here. If one did want to reduce the vibration, the engine could be made smaller to be 1/2 a 307 or 1/2 a 283. That would also help with fuel economy, which as you point out, is a major reason for the Vega. Also, a place for a balance shaft could be added to the block design.

    As far as cost and reliability of the all aluminum engine with liners, I would not repeat the same mistakes made with the Buick 215 and the Vega 4cyl. Primarily the mistake of going with die casting and semi-permanent steel molds. Instead I’d go with cheaper sand casting methods like Rover did when they took over the 215 (3500 cc) and made a good product of it. The ZL1 427 was also sand cast.

    I must admit, I’m not big on 4 cylinders anyway. My idea of the perfect Vega has a V8 under the hood. And when the Vega replacement, the Monza debuted in 1975 it had V8 and V6 factory installed optional engines. So if the Vega was introduced with an all aluminum 1/2 a SBC slant four in 1971 and this led to and all aluminum SBC by 1974 for the rest of Chevy’s larger cars because of the energy crisis, that means the Monza would have been introduced in 1975 with all aluminum 262 and 350 V8 engines. The Chevy 90 degree V6 (3/4 a SBC) could also have been produced in all aluminum form as well.

    1. With an inline four, the vertical shake is proportional to displacement and particularly stroke length. The math for it is a little beyond me, but fairly small increments of additional displacement make a perceptible difference. Bigger per-cylinder swept volume also tends to make an engine rougher — even with a V-8, a 327 is definitely sweeter than a 350. Therefore, a jump from 2,000 to 2,200 cc (or thereabouts), for instance, is enough to take an engine from “acceptable” to “coarse.” A 2,867 cc four would be noticeably rougher than, say, the well-known Iron Duke/Tech IV, which is not exactly a model of deportment to begin with. Balance shafts (an inline four needs two, counter-rotating to balance one another) make a huge difference, but they’re costly, particularly in the ’70s and ’80s due to patent issues, and their drive gear consumes a certain amount of power. (Historically, GM was very resistant to balance shafts for a long time for those reasons; unless I’m forgetting something, I don’t think any of their in-house, U.S.-market fours got balance shafts until MY1996.) From that standpoint, half a 283 (which would be 2,319cc) would be more pleasant as well as less thirsty.

      I think this kind of discussion is indicative of the challenges involved in designing a car like this, or anything that’s a couple of steps below the maker’s normal wheelhouse in size, price, and general purpose. (Particularly for the U.S. market in the early ’70s, when buyer expectations for “small” cars were hazily defined, to say the least!) If your starting point is to consider a ’70s Impala normal, a Chevelle the diet version, and a Nova small and dinky, something like a Vega is a real poser. Going back to the ’50s, if you asked American engineers and designers to come up with a small car and applied all the standard Detroit logic to it, you would get something like a Nova. If you sent them back to the drawing board to come up with something smaller and cheaper than the Nova, the tendency seems to have been to turn it into a junior Camaro. Which is fine if that’s what you’re after — with an appropriate engine, it wouldn’t have been any great trick to turn the Vega into a perfectly competent junior pony car. But again, that wasn’t the object.

      It’s not that reliable all-aluminum engines are bad or undesirable. The question is whether it was possible to do that while still keeping base prices below the Nova and without making other sacrifices beyond the ones the early historical Vega already suffered. An all-aluminum slant four like the one you describe would have cost more to manufacture than the 2300 engine and if the price were to be kept competitive, that would still have to come out of something. Selling a four-cylinder Vega that cost more than a V-8 Nova or Duster would have been quite a challenge even if it were objectively a better car.

      1. [quote]”An all-aluminum slant four like the one you describe would have cost more to manufacture than the 2300 engine and if the price were to be kept competitive, that would still have to come out of something”

        I wouldn’t be so sure of that, not if you count the design, development, and new tooling costs. I believe that the new Vega 2300 engine would have spent more on design, development and tooling costs than the 1/2 SBC slant four. Also, I think that the Vega 2300’s new OHC head would actually be more expensive than the all-aluminum SBC head if you count design, development and new tooling costs on it. Also keep in mind that the Vega head is only produced in numbers of around 400,000 heads a year, while an aluminum SBC/4cyl head has the potential to be produced at a rate of nearly 4,000,000 heads a year. Here, the Vega team can use the other, more expensive, Chevy model lines to help pay for its head.

        I know this is in retrospect, but the lined all-aluminum slant 4 would have, more than likely, been much cheaper in warranty claims. Of course they couldn’t know that then, but they could suspicion it because of the high risk, immature, never been done before, technologies used on the Vega 2300. Suspected or estimated warranty claims are estimated into the price of a new vehicle.

        1. For the most part, I think tooling and manufacturing costs (including both labor and materials) end up being considerably more significant than development costs — certainly at the kinds of volume Chevrolet typically built in those days. Aluminum costs substantially more than iron and with sand casting and pressed-in liners, there are more manufacturing operations involved. (The point of the linerless block exercise was to try trade off some materials cost to reduce assembly labor.) So, an aluminum SBC would cost more to manufacture than an iron SBC, which is likely a major reason why Chevrolet didn’t go that route. Again, the numbers are telling: If we assume aluminum heads would cost even $5 extra (a completely arbitrary number for the sake of argument), a complete switch-over would have cost an extra $20 million a year. You can amortize development costs, tooling costs, and even warranty costs, but materials and labor costs, you’re essentially stuck with.

          As far as tooling costs go, I will freely admit here that I am not entirely clear how much tooling can be shared by iron and aluminum versions of the same block or heads. (Presumably certain things can be freely interchanged, but engines are obviously much more complex to cast than something like brake drums.) However, this is another area where production volume becomes significant. Shared tooling makes a lot of sense if you want to create some variation that you expect to sell in modest numbers. To use the Corvair as an example, it doubtless made economic sense to make a four-speed manual transaxle by tinkering around with the existing three-speed; the four-speed was an extra-cost option and many buyers undoubtedly chose Powerglide instead. However, past a certain threshold, it’s not necessarily desirable. This is something Triumph ran into with the Stag V-8 and slant-four in the ’70s. The two engines were designed to be built on the same line, but that went from cost savings to inconvenience because Triumph needed far more fours than V-8s. At 400,000-odd units a year, the Vega would likely have needed its own engine line even if it were an SBC derivative.

          Assuming the Vega sold well enough to recoup the tooling and development costs either way (which I think is probably a fair assumption — the margins would have been juicier if the warranty costs had been lower, but I think sales were in the ballpark of what Chevrolet projected unless they were being especially silly), you’d still be left with the higher material and labor costs, which would have to go somewhere. Again, I think the fact that GM didn’t go to all all-aluminum SBCs is probably revealing here.

          1. [quote]”Again, I think the fact that GM didn’t go to all all-aluminum SBCs is probably revealing here.”

            Well they did, it just didn’t happen until 1997-98 (LS1). ;-)

          2. True! That gets into the tricky ontological question of whether the LS1 is still a SBC (well, except insofar as being a small block V-8 sold by Chevrolet, of course). I seem to recall that both the latter-day LT1 and LT4 had aluminum heads, although I’d have to double-check.

          3. Yes, the Corvette and Camaro 1992-1996 LT1 and LT4 engines used aluminum heads, and reverse flow cooling (like the ’55-’59 Pontiac V8). The exception was the Impala SS LT1 which used iron heads.

          4. Ahh, that’s right. That would also explain why my recollection was uncertain. (I could have looked up, of course, but I was preoccupied.)

          5. [quote]”Aluminum costs substantially more than iron and with sand casting and pressed-in liners, there are more manufacturing operations involved. (The point of the linerless block exercise was to try trade off some materials cost to reduce assembly labor.)”

            However, the linerless block also required some new expensive processes that lined blocks did not. Processes such as acid etching the cylinder bores to remove surface aluminum and expose the silicone wear surface, and iron plating of the aluminum pistons to prevent galling, scuffing, and seizing. So there were trade-offs.

          6. All true, and probably reflective of the often vast divide between ideas that look good on paper and ones that actually work well. In principle, this is why the corporate research staff and the divisional advanced engineers were separate. The research engineers would come up with all kinds of stuff that was interesting or promising and seemed like it might be commercially exploitable, but answering questions like, “Will it cost more than it’s worth?” or “How will it perform in our actual cars in real-world conditions?” was, for the most part, literally not their job — that stuff was supposed to be the divisions’ responsibility.

            The basic problem, pretty clearly, was not simply about the best way to make an aluminum block, or even whether an aluminum block was a worthwhile expense for a car like this in this era, but rather that GM had backed themselves into a corner by making a series of elaborate public promises about what the car was supposed to be and how advanced it was supposed to be in engineering and manufacturing. I’ve seen how that plays out in organizations at various points over the years: The boss makes some grandiose pronouncement about how some product or facility is supposed to be the “X of Tomorrow” (or something like that) and the people involved in the project get goggle-eyed and mutter to each other, “What is that even supposed to mean?” Organizational pride ends up pushing some feature or innovation that isn’t necessarily a good idea just so they have something to point to and say, “Look, it’s the X of Tomorrow!” Proven engineering may be cheaper, more dependable, or even more effective, but it’s not whizzy and brag-worthy.

      2. [quote]” If you sent them back to the drawing board to come up with something smaller and cheaper than the Nova, the tendency seems to have been to turn it into a junior Camaro. Which is fine if that’s what you’re after — with an appropriate engine, it wouldn’t have been any great trick to turn the Vega into a perfectly competent junior pony car. But again, that wasn’t the object.”

        Maybe that was Chevy’s object. In a lot of ways, the Vega is the Corvair “10 years after” (no surprise since both were the brain children of Ed Cole). The 1960 Corvair pioneered a new genre in American automobiles, that of the sporty compact car (later to be known as “pony cars”). This was followed in 1961 by more GM sporty compacts like the Pontiac Tempest and Olds F85. For once, Ford was caught flat footed by GM. It took Ford until April 1964 to respond with their Mustang and the rest is history. The sad thing is, if you look at a 1963 Pontiac Tempest convertible with a 326 HO engine, it is every bit as sporty as the Mustang, and could run circles around any ‘64-‘66 Mustang except for the Shelby GT350.

        Fast forward 10 years, and history repeats. Chevy introduces a sporty sub-compact (effectively a Junior Camaro or Camaro II) and invents another new genre in the American car market. The Ford Pinto, which is a sub-compact parallel to the 1960 Ford Falcon, is dowdy by comparison and Ford is again caught flat footed just like 1960-61. It takes Ford until 1974 to come up with a pinto based sporty sub-compact to compete with the Vega, they call it Mustang II. And history repeats.

        So by 1974, Ford’s Maverick is left to compete against Chevy’s Camaro and Nova, while the Chevy Vega (and later Monza) competes with Ford’s Pinto and Mustang II. The Vega was the Camaro II, or junior Camaro, and it beat Ford’s Mustang II to the punch by 3 years. Had the Vega not been plagued with engine and rust problems, I don’t think the Mustang II would have been nearly the sales hit that it became. Of course the Arab oil embargo helped too.

        1. I’m of two minds about this. On one hand, I think it’s clear the Corvair was not conceived as a sporty car or a pony car and the fact that it sort of became one was largely an accident. While I’m sure Chevrolet marketing would have loved to say it was all a brilliant plan, the Monza was both an afterthought and an unexpected success. The initial 1960 Corvair was positioned as a very basic economy car, a bigger but still very basic American reply to the popularity of imports and the Rambler. The same was true of the 1961 Senior Compacts, although they were obviously a couple of notches up the scale in terms of content. The divisions’ marketing departments were not oblivious to the success of the Monza and tried to run with it, but cars like the F-85 and Tempest were certainly not conceived as sporty cars. They also weren’t all that successful, at least in GM terms, and I’d say that it was GM’s divisions who were caught off-guard by the Ford Fairlane, which was a bigger midsize car for about the same price as a Special or F-85. (That was clearly the impetus for the move from Y-body to A-body for 1964.) As for the Mustang, its great achievement, and one of the ways it ended up vastly more successful than the ’63 Tempest Le Mans 326, was that it was an affordable specialty car with its own distinct body, not simply a Falcon Futura or Fairlane hardtop (despite its mechanical commonality with them), so it was a clearly different car rather than a trim job. Chevrolet didn’t have that at the time; the second-generation Corvair two-door hardtop was a very pretty car, I think, but from a marketing standpoint, even the Monza and Corsa were still burdened with being positioned as “sporty versions of the Corvair” rather than “sporty cars.” (It may sound like hair-splitting, but the sales figures suggest it made a real difference.)

          That said, it’s true that by the late ’60s, whatever interest American buyers had in plain-vanilla economy cars either withered or shifted to imports like the Volkswagen Beetle and Datsun 510. (Not necessarily on an individual level, of course — I don’t assume that the same people who bought a Falcon in 1960 necessarily bought a Datsun in 1969, just that there was likely significant demographic overlap.) The most successful U.S. compacts, like the Maverick, Valiant Duster, and the Nova coupe, ended up positioning themselves as quasi-pony cars for younger buyers who couldn’t afford a new Mustang (base prices of which had increased about 20% since 1965). Some of those cars, like the Duster, didn’t see daylight early enough to directly influence the Vega’s design, but I assume this is all stuff a competent market research staff would have pointed out. So, in that sense, the Vega may have been positioned intentionally as a sort of a mini-Duster. It did come out that way, so conscious or not, it was probably a sensible move.

          However, Chevrolet really didn’t try to market the Vega as junior Camaro. It launched with four different body styles, not just a coupe, and the advertising and even dealer promotion (which compares it to the Ford Cortina and Toyota Corona Mark II) pushed it as an affordable small import fighter. One could certainly argue that it was most desirable as a GT coupe, and the coupe was consistently the best-selling body style by an overwhelming margin, but if that was the plan, it appears nobody told the ad agency. In terms of price and content, it also seems like someone (according to DeLorean, upper management) was very determined that the Vega maintain a specific distance from the Nova in price, which wouldn’t have been as much a concern if it were really intended as a junior pony car.

          Also, even if the Vega had been intended as a junior Camaro, which I tend to doubt, Chevrolet certainly didn’t invent the genre. Ford had the Capri, of course, which WAS intended as a junior Mustang (mostly for Europe, but it ended up selling pretty well here), Opel had the Manta, and Toyota had the Celica (which debuted in Japan about 10 weeks after the Vega and came to the U.S. a year later).

  43. And speaking of cost. Just think what would have been possible if Ed Cole had taken all the money GM flushed down the toilet on the abortive GM Wankel program and used it to produce all-aluminum 4, 6, and 8 cyl passenger car engines instead. Hindsight is awesome. ;-)

    1. At some point Popular Science or some such magazine wrote that the tall driveline hump in the H-body cars was designed to accommodate the high output shaft of the GM Wankel engine. They went on to say that if the hump was lowered, that could be taken as an indication that the Wankel was well and truly dead. I don’t know if they lowered the hump, but we know what happened to the Wankel.

      1. There’s still a lot that’s vague about the GM RCE program, but what is clear is that it’s probably just as well that it never made production.

        1. Agreed. It would have been the wrong engine at precisely the wrong time IMO. GM’s wankel would have had the reliability/longevity of the Vega 2300 engine, with the gas mileage and emissions of a 350+ cid piston engine, and the driveability/torque curve of a high strung, small displacement, racing engine. The only thing the wankel has going for it is power/weight ratio.

          1. I don’t know about the torque curve, honestly. The GM RCE was quite large for a production rotary. GM officially described it as 266 cubic inches, which I think meant an actual geometric displacement of 133 cubic inches or a bit under 2.2 liters. So, it had substantially more displacement than any of the production Mazda or NSU rotary engines, even the JDM-only three-rotor 20B; for comparison, the Mazda 13B and RENESIS engines are 1,308 cc. So, it would certainly have had more torque than other rotary engines, although how well it would have performed in the real world we’ll never know. (My guess would be something in the league of the mid-70s odd-fire Buick V-6, but I’m really just speculating.)

            The emissions were actually the major selling point, believe it or not. The appeal of the rotary in its heyday was that it was much cleaner on NOx, which was seen as a major technical problem for reciprocating engines. The rotary’s higher HC emissions were more easily managed with thermal reactors, so it was seen as a worthwhile trade-off, at least before the embargo. Until the development of the three-way catalytic converter, there was a lot of wailing in the auto industry that the NOx standards would be technologically infeasible.

            As for reliability, that’s likely true. What little is known about the GM RCE program implies that because GM opted out of the usual NSU-Wankel information-sharing agreement (which as I understand it is part of why GM paid so much in license fees), they spent a lot of time and money struggling with problems NSU or the various other licensees had already faced and addressed. That’s not a reassuring point and if the engine had gone into production on schedule, I think there was a high likelihood that it would have been seriously under-developed.

          2. [quote]”GM officially described it as 266 cubic inches, which I think meant an actual geometric displacement of 133 cubic inches or a bit under 2.2 liters.”

            According to an April 1974 Popular Science Magazine (article can be found on google books), the Vega’s RC 206 2-rotor wankel was rated at 206 cid. And a wankel engine’s swept volume is rated at 2/3 a piston engine’s swept volume since only the cell volume from 2 of the 3 cell volumes is counted.

            A piston engine with an equivalent swept volume to a 206 cid wankel would displace 309 cid. Once you understand that, then you understand why wankel engines seemingly make large power for small rated displacements and return such lousy mpg per rated displacement. The RC 206 would have been an obvious replacement for Chevy 307 and 305 V8s and all V6s.

            However; unlike the 305 V8 piston engine, the RC206’s peak power and torque were at much higher rpm: 140 net HP @ 7,000 rpm, and 175 lb-ft @ 4,000 rpm. Like I said earlier, “high-strung” like a 302 Z28, but with anemic torque production.

          3. I took the time to look up my notes on this and there were two different rotary engines: The RC-206, bound for the H-body, and the one I was thinking of, the RC2-266, which was considered for a future Corvette (and also a successor to the Opel GT). (I had mistakenly conflated them, which is what I get when I don’t bother to double-check.) Your math on the equivalent displacement is incorrect, though. The geometric displacement of the RC-206, based on the numbers there, is 1,690 cc. (The RC2-266 was 2,198 cc, giving about 40 more horsepower.)

            Deciding how to rate a rotary engine’s swept volume to make it comparable to a reciprocating engine is a convoluted subject and there were several different schools of thought on it. The general thinking in the U.S. was that a 1.7-liter rotary would be equivalent to (yes) a 3.4-liter reciprocating engine in power and a 5.1-liter engine in fuel consumption. (Oops.) Japan at the time would have treated it as 2,535 cc for tax and licensing purposes.

            Still, 1,690 cc was still almost 30% bigger than a Mazda 13B, so not only would the RC-206 have had more peak torque than the 13B (which at the time was rated 117 lb-ft @ 3,500 rpm SAE net), the whole torque curve would have been fatter. Certainly not as fat as 5.7-liter V-8, but not bad for the era. It undoubtedly would have been thirstier than the Buick V-6, though.

            The problem rotary engines face in terms of specific fuel consumption is that combustion chamber surface area is inherently very large, so you get poor thermal efficiency and opportunities for fuel to re-condense in the chamber. (Mazda’s 16X, which may or may not ever see daylight, is supposed to use direct injection, which would likely solve the latter problem, but not the former.) Cars with thermal reactors also needed a fairly rich mixture to encourage catalysis, which didn’t help at all.

          4. [quote]”Your math on the equivalent displacement is incorrect, though. The geometric displacement of the RC-206, based on the numbers there, is 1,690 cc.”

            I calculate volumetric displacement the same way GM did back then:

            Popular Science April 1974.

            The article starts on page 84. It quotes cell volume at 845cc. 2 cells x 2 rotors x 845cc equals 3,380cc rated displacement. Actual swept volume is 5,070cc.

            [quote]”The RC2-266 was 2,198 cc, giving about 40 more horsepower.)”

            According to a November 1973 Motor Trend magazine, the RC2-266 was the Corvette 2 rotor wankel. Chevy rated it at 266 cid displacement and its total displacement is 400 cid. It was rated at 180hp at 6,100 rpm. Individual cell size was 1090cc. They also were playing with a 3 rotor version of this engine, the RC3-309. The rated displacement was 309 cid, the total displacement was 463 cid, and it was rated at 210hp at 6,300 rpm.

            The Motor Trend magazine goes on to add that Chevy also had a 4 rotor Corvette wankel, the RC4-390. Chevy says this 4 rotor wankel displaced 390 cid for which the total displacement was 585 cid. Single cell volume was 800cc. Chevy says that it was the largest displacement wankel ever put into a car. It was rated at 300hp at 6,000 rpm but adds that it could be easily developed to 420hp at 7000 rpm. All figures are net hp.

            Like it or not, that is the way GM calculated their wankel engine’s displacement back then. Basically, Chevy rated their wankel engines twice the displacement as Mazda did theirs. Mazda only counts the displacement of one cell per rotor and not two like GM. A December 1973 Car and Driver magazine makes that clear.

          5. I’ve read the article (and had before you brought it up). My point is simply that in an apples-to-apples comparison, the GM rotary engines, even the RC-206, were substantially bigger than any of the Mazda and NSU rotaries that actually made production — almost 70% bigger than the KKM 612 and almost 30% bigger than the Mazda 13B — and thus assumptions about the torque output and flexibility of the GM engines based on those much-smaller rivals are not necessarily going to be accurate. More displacement translates into more torque throughout the rev range, regardless of where the peak falls.

          6. [quote]”and thus assumptions about the torque output and flexibility of the GM engines based on those much-smaller rivals are not necessarily going to be accurate.”

            What I posted was not an assumption, and certainly not based on any foreign wankel. GM rated the RC-206 at 140 net HP @ 7,000 rpm, and 175 lb-ft @ 4,000 rpm. Notice the peak torque number and rpm, and the rpm at which peak power is achieved. It’s not nearly as drivable as a 5.1 litre V8 which this engine would get basically equal fuel economy with.

            By comparison, a Monza 305 cid V8 engine was rated at 145 net HP @ 3,800 rpm and 245 lb-ft @ 2,400 rpm. From these ratings, I think it’s pretty clear which 140 hp engine is more drivable. The only advantage the wankel has is it weighs 190 lbs less than the V8.

          7. The shape of the torque curve is ultimately more important than the torque peak, though, so the projected numbers aren’t necessarily revealing. Of course, this assumes that the projections would even be accurate for a production RC-206 that had gone through EPA 50,000-mile durability testing, so who knows? Without actual driveable engines to compare, it’s all kind of circular speculation.

            As I said the other day, weight was NOT the rotary’s only advantage or even its principal draw. The primary rationale for adopting the rotary was lower nitrogen oxide emissions, something that, when the GM RCE program began, looked like it was going to be very difficult to achieve with existing reciprocating engines. (In fact, automakers in both Detroit and Japan spent a couple of years insisting it was going to be impossible.) The reason GM took on the project was as a contingency against the possibility that their existing engines, like the 305 and 350, might have to go away entirely. The rotary seemed like one of the few feasible alternatives that could be added to existing cars with relatively little hassle. Obviously, that didn’t happen, but when GM signed the license agreement, that was the scenario they were envisioning. It had nothing to do with fuel economy and the prospect of reducing engine weight was sort of a tertiary concern.

          8. Here’s how a wankel powered 1974 Vega mule stacks up against a production 1977 305 Monza:

            Popular Science Apr ’74 Popular Science Apr ’77
            1974 Chevy Vega mule 1977 Chevy Monza
            RC 206 2 rotor Wankel SBC OHV V8
            206 cid rated, 309 cid actual 305 cid (displacement)
            140 net HP @ 7,000 rpm 145 net HP @ 3,800 rpm
            175 lb-ft @ 4,000 rpm 245 lb-ft @ 2,400 rpm
            345 lbs (engine weight) 535 lbs
            B&W T-50 5sp Manual 3sp Auto
            3.36:1 (axle ratio) 2.29:1
            16-20 MPG 17.6-22.4 MPG
            18 MPG average 20 MPG average
            2650 lbs (curb weight) 3140 lbs
            9.9 sec (0-60mph) 10.7 sec

            An all-aluminum version of the 305 SBC would take away the wankel’s only advantage (weight savings). Right about now, the Buick 215 V8 starts looking like a really good alternative to either engine IMO.

  44. I have a couple of final things I’d like to add to this discussion, then I’m done. The first is the Buick 215 Vega engine swap. This engine swap seemed somewhat popular in the early and mid-1970’s for those looking for economy rather than performance. I was looking through a March 1975 magazine article written by Herb Adams about a D&D Fabrications $850 engine swap. They took a 4 speed Vega with a 2.53 rear axle and swapped in a Buick 215 V8. Herb Adams reported that the engine swap only added 30 pounds to the front of the Vega. He goes on to report that the 2,395 lb Vega ripped of 0-60mph times between 8 and 8.5 seconds and the ¼ mile in 15.5-16 seconds with copious wheel spin. The best part; however, was the gas mileage: 24mpg city/30mpg hwy. So here is an engine swap where a 3.5 liter V8 gets almost the same gas mileage as the Vega 2.3 liter I4 and only weighs 30 lbs more.

    My second point is in regards to an all iron 4cyl for the Vega. I find it interesting to note what engine replaced the Vega 2.3 liter in the Monza in 1977. It was the iron duke 2.5 liter I4. From a design standpoint, this engine was basically ½ a Pontiac 301 V8, although it wasn’t a slant engine. It shared pistons and rods with the 301 V8, and the head port and chamber layout was the same design. This 2.5 liter I4 didn’t incorporate balance shafts until 1988. Apparently buyers of cheap GM econoboxes weren’t overly concerned with NVH until the late 1980’s. So, if Chevy designed the Vega’s I4 engine from scratch in 1968-69, it is very possible that Chevy would have made an extremely similar engine to the iron duke, but based upon the 283, 302, or 307 SBC instead of the Pontiac 301. And DeLorean may have even found a way to stick his OHC head on it as part of a Vega Sprint option package. Who knows, but it’s fun to speculate.

    Anyways, thanks for this site Aaron, it’s filled with fun facts, and I learn something every time I visit. Also, thanks for taking the time to discuss this with me.

    1. I have to say I’m skeptical of the 3.5 Vega fuel economy figures — I don’t doubt your report of them, but they make me wonder if the car had the correct speedometer gears for the axle. With less weight and a taller axle ratio than a Y-body Special, I can definitely see breaking into the 20s when taking it easy, but 24/30 mpg sounds optimistic by a good 15%. Don’t get me wrong, it sounds like a fun project.

      I think the Iron Duke is probably a good comparison point for what Chevrolet likely would have done. Since the Chevy II four had similar commonality with existing Chevrolet engines, I think they may have sacrificed some parts commonality for a physically smaller, lighter engine. (The latter was less of a concern for the Iron Duke because the 301 was already scaled down compared to the Pontiac 350 from which it was derived.) They might still have had a collaboration with Cosworth, which might even have worked out better through having a stronger block. There were a fair number of OHC and DOHC conversion engines in this era, most of them with iron blocks.

      I do think the mediocre refinement of GM’s four-cylinder engines ended up hurting them, particularly by the ’80s, compared to the latest Japanese fours. This also gets into the point about design comfort zones; for U.S. engineers, engines 2 liters and under were dinky loss-leaders, but in Japan that was a pretty big displacement for middle-class cars. There were some 2.8 and 3.0-liter sixes there, but you paid through the nose for them (not just upfront, but every two years), so it didn’t make sense for those to be the bread and butter. A different set of expectations.

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