The Cosworth Vega. Chevy’s Almost Muscle-Bound Econobox

It was a time when American car manufacturers were grappling with the notion of building emissions-friendly performance cars. This was a notion that had not been pondered before. It was 1975, and Chevrolet introduced the Cosworth Vega.

Although the Vega model was introduced in 1970 and had a run of seven years, the Cosworth version was only produced for two short years (1975 and 1976). The econobox performer featured several firsts for Chevrolet. The largest being the sixteen-valve, twin-cam engine. This small powerhouse utilized supporting hardware like the first factory-installed, stainless-steel exhaust header and the first use of electronic fuel injection.

Cosworth Vega

The hopped-up Vega was a great looking car. Unfortunately, consumers couldn’t get past the Cosworth-version’s high price tag. Images: Mike Slade

From The Beginning

Introduced as a 1975 model, the Cosworth Vega was actually conceived four years prior. In 1971, Chevrolet General Manager John DeLorean, contacted Cosworth Engineering of England about an idea he wanted to implement. Just like the Pontiac GTO, he considered the same approach with the Vega GT – a good looking coupe with a surprise under the hood. With that, development of the Cosworth Vega began. He worked with Cosworth on a race-inspired version of the four-cylinder Vega engine.

Cosworth was instrumental in designing the 16-valve cylinder head, which was constructed of aluminum alloy, which used sintered-iron valve seats and cast-iron valve guides. The two overhead camshafts were housed in a removable cam-carrier, which also served as a guide for the lifters. Each camshaft was driven by a gear found on the front of the head, and along with the water pump and fan, were turned by cogged rubber belt.

Everything is still original on this car, including the tires. – Paul Chicky

To create the Cosworth variant, the standard 140 cubic-inch Vega engine was actually de-stroked to 122 cubic-inches. Inside, chrome-plated piston rings were used with the forged-aluminum pistons. The crankshaft and connecting rods were forged steel. Sounds bullet-proof.

Cosworth Vega

Not exactly a buy one, get one deal.

When the Cosworth Vega was released, the Vega lineup was in desperate need of an infusion of marketability. As the 1971 Vega hit showrooms, DeLorean stated in a Motor Trend interview, “Vega will be the highest-quality product ever built by Chevrolet.” Little did engineers realize that the world’s first all-aluminum engine would prove to be a failure.

Developed by GM and Reynolds Aluminum, the block was cast from a high-silicon content alloy. Initial testing showed that its erosion properties resembled that of steel, but cylinder wear accelerated rapidly after the odometers hit 40,000 miles.

When DeLorean approached Keith Duckworth of Cosworth Engineering to see if the collaboration could design a race engine for the Vega, the intent was to capture the SCCA “B” Production class and Europe’s two-liter sports car class. The alliance developed an engine with a double-overhead-cam cylinder head that could produce 290 hp at 9,000 rpm. The engine relied on two 40 DCOE Weber side-draft carburetors. In order to meet homologation rules, 1,000 were to be built. On paper, the design looked to have an edge over other cars in those classes.

But, the Cosworth package stretched the limits of the Vega’s engine block, and the 12.0:1 compression ratio caused it to crack. Duckworth eventually lost interest in the project, and DeLorean considered how best to salvage/use the engine. The solution was to dial it down so it could be used for street use. That presented another problem, as the Weber carburetors would not pass emissions testing. It was suggested that fuel injection was the solution. General Motors’ Rochester Division wanted control over the entire project, but ultimately, the Bendix company was given the nod.

I purchased it from a gentleman that actually worked in the Lordstown plant during the ‘70s – Paul Chicky

Timing can either make – or break – a given outcome. Unfortunately for Mr. DeLorean, the government tightened emission regulations for 1974. Even with the new fuel injection, that meant it was back to the drawing board for the Cosworth’s engine. Sure, 290 horsepower would have been great in such a small car, but to pass the new emission standards required reducing the compression ratio from 12.0:1 to 8.5:1. That single change cut power to a measly 110 horses. In hindsight, knowing the expedited cylinder-wear issues the aluminum engine possessed, it was probably a good thing.

Cosworth Vega

As delivered from the factory. The color-keyed floor mats were a $14.00 option. The five-speed added another $244.00.

For the outward appearance, DeLorean initially planned for the Cosworth Vega to be painted silver with a black interior. When it was finally released in 1975, he had changed his mind, and all 1975 Cosworth Vegas were painted black with gold trim. The color scheme was unique to the car.

At a cost of $5,916, the Cosworth packaging resulted in the car costing twice as much as a standard Vega. It was the second most-expensive Chevrolet model that year. In fact, the headline of a G.M. advertisement in 1975 read: Cosworth. One Vega for the price of two. When Cosworth Vega production ended in 1976, there was a total production run of only 3,508 cars.

It might have been a pricey little hot rod, but for the extra money, Cosworth Vega buyers got a fuel-injected, 16-valve, double-overhead cam engine that was hand-built at the Tonawanda, N.Y., plant. Reports vary about the actual 110 hp at 5,200 rpm that was reported to be delivered through a four-speed gearbox. Some say it was closer to 100. The chassis had a heavy-duty suspension with front and rear sway-bars, and unique gold mag wheels with Goodyear radial tires. Most interiors were black, and the fully instrumented gold dash was engine-turned and was highlighted by a numbered plaque.

Chevrolet hoped to sell 5,000 of the performance compacts, but a mere 2,061 units were purchased in 1975. With that shortcoming, marketing stepped up in 1976, and seven additional colors were made available. The grille was redesigned, and the taillights were larger. Also, a five-speed manual gearbox was added to the options list.

Cosworth Vega

At $6,671.60, this Vega was only $600 less than a new Corvette in 1976.

Unfortunately, it didn’t help. In 1976, sales declined to 1,447. That left 1,492 surplus engines taking up warehouse space. It is reported that these sat around until the mid-1980s. That’s when 500 were dismantled and used for parts, and the remainder were sold for scrap metal.

A testament to originality, the Goodyear BR70-13 tires are the same ones the factory mounted on those aluminum wheels 43-years ago.

Paul Chicky of Greer, North Carolina, was not one of the 1,447 Cosworth buyers in 1976, but always had a soft spot for the econo-performer. “This car was built in March of 1976, and was first sold through Cecil Crews Chevrolet/Oldsmobile in Centreville, Alabama,” he said. “I purchased it from a gentleman who actually worked in the Lordstown plant during the ‘70s.”

Cosworth Vega

It’s not very often that you’ll see a Vega that has been treated to nearly flawless restoration. In fact, even after you look at this car, you’ll still likely not see one. That’s because Paul’s car has never been touched. “Everything is still original on this car, including the tires,” Paul affirmed. “In fact, the Cosworth Vega Association used this car as a template to grade the originality of other cars.”

Photo gallery

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The outstanding condition of Paul’s Cosworth is a testament to the care that previous owners bestowed upon the beleaguered small-package, would-be racer. In fact, Paul relayed that this actual car won First Place at the Cosworth National Concour in 2009.

About the author

Randy Bolig

Randy Bolig has been working on cars and has been involved in the hobby ever since he bought his first car when he was only 14 years old. His passion for performance got him noticed by many locals, and he began helping them modify their vehicles.
Read My Articles

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