Chevrolet Cosworth Vega

One model of car that you don’t see very often these days is a Chevrolet Vega.  Therefore last year I was surprised to not only see a Vega, but to see the premier model of the Vega, the Vega Cosworth Twin Cam model.

Chevrolet Vega Cosworth Twin Cam 1976  (5)

1976 Vega Cosworth Twin Cam

The Vega Cosworth Twin Cam model was only made in 1975 and 1976.  This was an attempt by General Motors to provide a performance car in the Vega model line up.  The standard engine in the Chevrolet Vega was a 140 cubic inch inline 4-cylinder 78 horsepower engine.  The optional engine for the Vega was an 87-horsepower version of the same engine.  As a result, the typical Vega was no performance car.

Chevrolet Vega Cosworth Twin Cam 1976  (6)

All 1975 Vega Cosworths Were Black, 1976 Models Had Other Colors

When the Chevrolet Vega was introduced in 1971 a more sporty GT  model was included in the Vega lineup.  My roommate at the University of Waterloo had a red Vega GT and he liked it.  This model had a 100 horsepower engine and some sporty trim styling.  Over the years and mostly due to EPA regulations this engine had lost power and by 1975 it only had 87 horsepower.  The Cosworth Vega was an attempt to enhance or even develop the sporty image of the Vega.

Chevrolet Vega Cosworth Twin Cam 1976  (7)

The Mag Wheels And Fat Tires Were Standard On the Cosworth Vega

The Cosworth Vega suspension had stiffer springs and shocks as well as torque-tube type rear suspension. to help improve the handling.

Chevrolet Vega Cosworth Twin Cam 1976 (1)

The Cosworth Vega Was A Hatchback Design

The Vega Cosworth Twin Cam engine was a destroked version of the standard 140 cubic inch Vega engine.  As a result of reducing the stroke from 3.63 inches to 3.16 inches the capacity of the engine was reduced to 122 cubic inches which translates into 2.0 litres.  The engine had two overhead camshafts and fuel injection.  For General Motors in the mid-1970s these features were considered quite exotic.  What I find very surprising is that this 2.0 litre engine with the name of “Cosworth” attached to it only produced 111 horsepower.

For comparison, the standard engine in the 1975 Saab 99 was a 2.0 litre 4-cylinder 115 horsepower engine.  This was four more horsepower than the Cosworth Vega and the Saab 99 weighed almost 300 pounds less than the Vega and the Saab 99LE sold for about $700 less than the Vega!

Chevrolet Vega Cosworth Twin Cam 1976 (2)

Twin Overhead Cam Chevrolet Cosworth Engine

The Cosworth engine was constructed totally from aluminum.  It had a 16-valve cross-flow head with almost 50 percent greater total valve area as compared to the standard Vega engine.  With all of these enhancements over the standard engine, one would have expected more than 111 horsepower.

In 1975 all of the Cosworth Vegas had 4-speed transmissions.  In 1976 a five speed transmission was available as an option.  This 1976 model shown here had the five speed transmission.

Chevrolet Vega Cosworth Twin Cam 1976 (3)

Despite The Cosworth Modifications The Vega 2.0 Litre Twin Cam Engine Only Produced 111 Horsepower

In 1975 the road test numbers for the Cosworth Vega were 0 to 60 mph in 8.7 seconds with a top speed of 107 miles per hour.  However in 1976 Road & Track reported a 0 to 60 mph time of 12.3 seconds with a top speed of 122 miles per hour.  These numbers are so widely different that the gearing of these two cars must have been very different.

Chevrolet Vega Cosworth Twin Cam 1976 (4)

The Gold-Toned Engine-Turned Dash With The Black And White Instrumentation Is Attractive

The Cosworth Vega was not an inexpensive car.  In 1975 the factory selling price was $5,916; compare this with a Corvette convertible which had a selling price of $6,550.

Each Cosworth Vega had a special dash plaque stamped with a unique Cosworth serial number.  The 1975 model year cars are numbered from 0001 to 2069, while the 1976 model year cars are numbered from 2070 to 3528.

By 1978, General Motors dropped the Vega model from its lineup.  I think that this was mainly a result of problems with the aluminum Vega engine.  General Motors dropped the aluminum engine as well as the Vega.  As I noted at the beginning of this post, Vegas are rare these days, so I guess that the American public dropped the Vega as well.

This entry was posted in Uncategorized. Bookmark the permalink.

15 Responses to Chevrolet Cosworth Vega

  1. rene veenis says:

    Dear Steve,

    In 1983, visiting New England USA for 6 weeks, I bought myself a car out of the newspaper ‘under $500,-‘ The Hartford Cronicle (Connecticut), instead of hiring one. I figured out this was supposed to be defenitely cheaper. And this did, but mainly because I was lucky I suppose. It was a Chevrolet Vega. Reading the ad, I read “Chevrolet”, and I always wanted a Chevrolet as a child. But Vega??? Anyway, I bought the car for 300, drove more than 3000 miles in it without any trouble to be mentioned – some dust in the carburettor after a stillstand of a year – and left the car at the seller, who sold it for me for 400 after half a year. But coming to your last line, I met a few people in the US during my trip, telling that I had never heard of a Vega before. This is, because it was never imported to Europe. Well, anyone I spoke about the Vega had it’s definite opinion, and the one I do remember the best still today is: “Oh, don’t you worry boy, the Chevrolet Vega was the worst car ever produced in the United States of America”.
    But I had my lovely trip in the car with my girl of that time, crossing New England in Autumn and the Canadian border up to Toronto and Niagara, so it’s still lovely to read your article about a Cosworth execution. This is the very last thing I would ever expect about a Vega. If I must make a comparison to any car, I would mention the Vauxhaul Astra, anyway a 100% run-of-the-mill no-nonsense stripped to the bottom no luxury car with no pretentions whatsoever. Even more fun to read your article! Thanks.



    • Hi Rene,
      I enjoyed hearing from you again! Unfortunately your good experience with the Chevrolot Vega was not the usual experience. The car did not have a good reputation. These days Vegas are rarley seen, at least I don’t see very many. I don’t think that they were as bad as their reputation, but freqently bad news travels faster and lasts longer than good news.
      Steve McKelvie

    • hammer says:

      The Vega was essentially the Opel Ascona/Manta

  2. I think that there are two fundamental reasons for the rarity of Chevrolet Vega. First, the bodies rusted horribly, at least in parts of the country where salt is applied to roads in the winter. Second, differential expansion between the cast iron head and the aluminum crankcase caused the head gasket to leak. The leaking coolant destroyed the cylinder finish, requiring acid etch-back and special tooling to resurface the silicon-aluminum cylinders. The all aluminum cylinder had not been perfected in the era the Vega was manufactured.
    Maintenance of the body rust was nearly impossible to keep ahead of and rebuilding of the engine was an expensive procedure so there was little to justify keeping the car. I owned a 1973 Vega and can personally attest to the difficulties.

  3. Stephen Kirkey says:

    In 1979 I acquired a 75 Vega Hatchback 140 ci 4 on the floor with a 2 barrel holly carburetor. It was my first car kept it for 4 years. First thing that was done shortly after purchase was to disconnect the pollution bump. The car ran well on warm weather but was a bugger the start in the winter months. On one winter trip to my girl friends family in Vankleekhill, ON. it got so cold the engine would not turn over, her father used his car to push start it (advantage of a manual transmission) when it was up to speed I popped it into second gear and gave her the gas and she reluctantly sputtered to life. It had a transferable warrenty and when it stared burning oil GM honored it and repaired.. they had to do it twice (second repair worked) I used it while at college and for my first job after graduation. I it the liked that car, regardless of the bad rep it got, so much in fact that 30 years later I purchased a near show car quality 75 Cosworth Vega (with out the fuel injection) this one is fitted with twin side draft Weber carbs. I wish I had one of these back in the 70’s it moves and has a robust sound to it. I enjoy driving it in the summer months and people stop and ask what it is or have a flash back down memory lane , most appreciated it and ones who remember when they were common on the road say they haven’t seen one in like forever. Others, well there is always one or more in every crowd who mock the car because of an exploding engine experience or premature rust ruined their ride. Ive always like the style and shape of this car and people have also made same comments.

    • craig says:

      I too like the appearance of the Vega but I am quite confident that I am not the only one in the crowd that is aware of the failings of both the body and engine. I rebuilt my engine in my parents garage, added racing exhaust headers and a custom exhaust but the body rusted to pieces. The left front fender was actually flapping in the wind because there was not enough steel left to keep it attached to the car. the windshield channel was severely rusted, the rear wheel wells self enlarged due tot he rust. Really, you would not want to own one that was ever exposed to road salt. Before purchasing any Vega, it should be inspected on a lift to determine how much, if any, rust there is on the undercarriage and suspension.

  4. Below is an email message that I got from Charles Hanson about hs experiences with a Cosworth Vega:


    Great to see your post about the Cosworth Vega. I raced #267 in 1978 and #2261 in 1979 in Showroom Stock A against Porsche 924’s, Datsun 260Z’s, Saab 99’s, and Saab 900’s. Patrick DiNatale in Midwest Division and Ron Smaldone in Central Division also raced CV’s. Smaldone qualified for the runoffs in Atlanta in 1979, but took a Mustang to the event. The 75 Cosworth wasn’t a very good car because of the way Chevrolet did the panhard rod. They fixed the design for the 76 model and it was a remarkably well balanced vehicle.

    I will say that the five speed transmission was a terrible mistake on Chevy’s part. The shift linkage was inside the transmission and it didn’t like fast shifting between first and second near redline. Would regularly try to be in both gears at once. All of us racing 76’s wound up running the four speed transmissions (which required a vehicle change because the floor pans were different).

    Your pictures show one of the great features of the Cosworth; i.e. the tri-Y exhaust header. Smaldone discovered that from the end of the header through the tailpipe was exactly the same as the regular Vega, and that the regular Vega’s exhaust systems would rust out just ahead of the catalytic converter. He went looking for badly corroded pipes and put them on his car. About 6 -10 laps into a race, they would break just ahead of the catalytic converter and give him an open exhaust. The resulting exhaust length gave him an immediate gain of 10 – 15 horsepower that instantly made him competitive with the Porsches’ and Datsun’s. Eventually the Steward’s caught on to what was happening and informed him that the car had to finish the race in Stock condition (i.e. with an intact exhaust system). That is why he wound up taking a Mustang to the Run-Off’s.

    I never got mine to be competitive in National racing, but did win two Regional races, set a lap record at Waterford Hills, and finish second in the Central Division Regional Championship in 1979. I raced for twelve years and it was absolutely my favorite race car. Always thought that it would have made an outstanding ITA car, but by then I was looking at putting two daughter’s through Purdue University.

    Charles G Hanson – RRB

  5. Tom watts says:

    My name is Tom Watts, Im thinking of buying a 75 vega Cosworth for 9,000 cash with 22,000 miles very clean car, Is that a good deal…

    • Hi Tom! I don’t think that $9000 is too much to pay assuming that the car is in the kind of condition that I would expect a car to be with only 22,000 miles. I think that the owner is asking for all the money that the car is worth.
      The question that I think that you need to answer is first are you convinced that the mileage is really 22,000? And if you believe that it does only has 22,000 miles on it, then what is the explanation for only having 22,000 miles? For example, was it because of mechanical issues that were not repaired for years and the car just sat in disrepair?
      If the car turns out to be a good car then you should be OK. I think that the interest in Vegas is rather low, so in the short term I would not expect the value of the car to soar. But if interest in the Vega begins to increase then you have the the most desirable Vega.
      Good luck!
      Steve McKelvie

  6. Tom watts says:

    Thanks for your quick reply….happy new year

  7. John Rice says:

    Great to see something from someone who also raced a Cosworth! I raced mine in SCCA San Francisco Region, won my Regional Championship, and qualified for the Runoffs in 1978. It was a wonderfully balanced chassis, with OK brakes that were only good for about 3 laps at a qualifying pace, but woefully underpowered compared to the 280Zs It make up for the power disadvantage via handling well. Mine was a ’75 and wasn’t eligible after my first year of racing. Just as well, as I was “racing myself into the poorhouse”. :-> At that time J.D. Fredzakas [spelling?] was also running a Cosworth in the East and made it to the Runoffs, but the poor cars didn’t stand a chance on the long straights. I did a “fun run” once with an open exhaust and was astonished at the power increase. Just like they said, it would pull 10K with ease! In those days Product Promotion was most helpful with issues but I was probably the only legal SSA car running in my area so their help was confined to keeping it in one piece. This proved beneficial when I ended up on the podium at the the first ever Pacific Coast Road Racing Championship races as the winner was DQ’d for incredibly obvious cheating [he should have run CP!].

    Still, great memories and I have more than once considered buying one to run in vintage races.

  8. Robert Spinello says:

    They are not as rare as ANY Japanese shitbox from the 70s

  9. Robert Spinello says:

    Let’s see what a few real car authorities have to say in retrospect

    Motor Trend’s Frank Markus said after driving my 6k mile ’73 Vega GT in 2010, “After a few gentle miles, I begin to understand how this car won its awards and comparison tests.” “Well-maintained examples are great looking, nice-driving, economical classics—like Baltic Ave. with a Hotel, the best ones can be had for $10K or less.”

    Motor Trend’s Frank Markus said after driving my 2k mile ’76 Cosworth Vega in 2013, “Stylish and historically significant but ridiculously overpriced in its day and ultimately a bit unfinished, the ultimate Vega now represents a serious collector bargain.”

    Hemmings Classic Car editor Craig Fitzgerald said, “The idea that the 1971 to 1977 Chevrolet Vega was an unpopular lemon from day one is a myth.”

    Hemmings Classic Car editor in chief Terry Shea said, “Chevrolet did save the best for last in the form of the sublime Cosworth Vega, a sports car with an exotic double-overhead-cam, 16-valve, four cylinder engine; a suspension to match and sophistication decades ahead of most other cars.”

    Cars in Depth May 26, 2013 said, “GM is not ashamed of the Vega and they have one on display at the GM Heritage Center.”

    Portraits of Automotive History “Falling Star: The Checkered History of the Chevrolet Vega” editor Aaron Severson said, “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.”

  10. Robert Spinello says:

    “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”.
    Road Test October 1976 “The Great Supercoupe Shootout” — Alfa vs. Mazda vs. Lancia vs. Saab vs. Cosworth Vega

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s