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.
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.
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.
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.
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!
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.
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.
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.