GM Engines: The Good, the Bad, the Aluminum

A powerful engine in the 1950s went a long way toward captivating the American public, which helped propel General Motors and its engine technology to global automotive dominance.

It was the era when engine designer Ed Cole gained fame for his small-block V-8, first used in the 1955 Corvette, an accomplishment that would put him in the GM presidency years later. The design has survived nearly 50 years and is now represented in Corvette’s LS1 power plant, an all-aluminum 345-horsepower small-block.

But what can you make of GM engines today? Is there anything left of that legendary quality and innovation? Is there anything that distinguishes a GM engine from a Ford or Toyota or Chrysler that ordinary car buyers would care about? Can a GM power plant deliver high mileage reliably?

GM engines and their accompanying transmissions have represented some of the best and worst engineering in the auto industry over the last several decades. In the latter category, you can include the four-cylinder engines that powered the early 1970s Chevrolet Vega and the Oldsmobile diesels a few years later that were ginned up from a gasoline-powered V-8. In the 1980s, GM miscalculated again, matching oversized engines with weak transmissions, resulting in widespread transmission failures and a consumer revolt.

Even today, GM is widely criticized by analysts and mechanical experts for its aging technology, which often lags that of it competitors by many years. The company continues to use two-valve, cast-iron block engines equipped with single camshafts and push-rods in many of its vehicles, to the dismay of critics. Even its new LS1 engine in the Corvette defies the standard for modern power plants, eschewing the multivalve, dual-overhead camshaft architecture that is standard at many of its competitors.

“They have an aged lineup,” said Eric Fedewa, forecast manager for GM’s Powertrain Division at CSM Worldwide, a market research firm. “But buyers don’t care. The bottom line is that most people shop cost, and GM has been able to hold down cost by making their product last. The current engines are very efficient.”

GM engine designers are the first to acknowledge that they won’t adopt new technology just for the sake of boasting. The company is aiming to produce low-cost, high-durability engines that will once again create enough consumer awareness to sell cars.

“The question is, what does a normal customer really need?” said Fritz Indra, executive director of advanced engineering for GM’s Powertrain Division. “Does every customer need a four-valve engine? Does every customer need an all-aluminum engine? A lot of customers are not interested.

“I don’t like to say old is bad and new is good,” said Indra, a native of Austria with a background in European engineering. “A very old engine can be a very good engine. We have to see how new technologies are fitting together with all of our engines.”

For many GM customers, that makes great sense. A lot of new engine technology is unproved, and the customer often pays the price when things go wrong. That’s why GM engines of established design have such a strong following. After all, GM did not become the world’s largest auto maker by building lousy engines.

Just ask Mike Berezny of Laguna Niguel. He has a Cadillac Sedan DeVille with 270,000 miles that he’s trying to sell for $3,600, figuring the original engine and transmission have lots of life left in them.

Potential buyers are dubious.

“I mostly get a lot of hang-ups,” Berezny lamented.

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People just don’t understand GM drive trains the way Berezny does. He once owned a 1979 Chevy van that accumulated 420,000 miles before the engine finally died. And then he put a new engine in it. If you think Berezny’s experience is unusual, check the classified ads. They’re full of GM cars and trucks with more than 200,000 miles on the odometer.

Three years ago, GM consolidated its worldwide engine and transmission operations into a single division, Powertrain. The company makes 27 different engines in North America alone.

Fedewa, the market researcher, said GM still sets the world standard in terms of automatic transmission quality. Although not widely known, GM Hydramatic transmissions are used by Volvo, BMW and Rolls-Royce.

Typical of GM’s engine lineup is its 3.8-liter, all-cast-iron V-6, a design that has been around for more than a decade. Its competition includes the Ford 3.8-liter V-6 with an aluminum head and a cast-iron block. While the GM 3.8 engine routinely runs more than 150,000 miles, Ford owners are lucky to make it to 80,000 miles without a blown head gasket.

“We still produce a lot of cast iron,” Indra said. “We are not abandoning our traditional push-rod V-8s.”

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But GM is being pushed toward aluminum, as are all auto makers. Although aluminum is far more expensive than iron, it saves plenty of weight and can help keep engines small. More than just worrying about the power-to-weight ratio, today’s engine designers are under pressure to produce physically compact engines, Indra said. New federal safety standards call for hoods that collapse when a pedestrian is hit, requiring more space between the thin sheet-metal hood and the solid engine.

GM is pushing ahead with an entire family of new aluminum engines. Typical is the LA50, designed by a team of GM engineers and Lotus Engineering in England. The four-cylinder, all-aluminum engine is compact and highly efficient. It is being produced in three factories around the world and will go into virtually all of GM’s small cars.

It’s the wave of the future. Whether it will measure up to GM engines of the past remains to be seen. In a future column, I’ll revisit the issue of aluminum engines and whether motorists can finally put their trust in them.

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Ralph Vartabedian cannot answer mail personally but responds in this column to automotive questions of general interest. Please do not telephone. Write to Your Wheels, Business Section, Los Angeles Times, 202 W. 1st St., Los Angeles, CA 90012. E-mail: [email protected].

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GM engines and their accompanying transmissions have represented some of the best and worst engineering in the auto industry over the last several decades.