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GM's radical 2009 design cuts cost and weight, saves space under the hood
In late 2005, Charlie Freese and Gary Arvan sketched out a radical new design for a diesel engine.

On paper, it could eliminate about two dozen parts, slash the high cost of diesels and save space, too.

Two weeks later, the two General Motors engineers stood before senior managers from GM's Powertrain division, seeking approval, and millions of dollars, to develop the design.

The payoff, all knew, could be huge.

Coming to America
Diesels, which can be about 25 percent more fuel-efficient than gasoline engines, are poised to power more U.S. cars and trucks. Diesels already power half of all new cars in Europe. Virtually all European and Japanese automakers plan to introduce diesels in the United States around 2010.

Freese argued that GM needed to risk the radical engine makeover. “In today's auto industry, you can't afford to develop an average anything. You can't set your goals that you want to be like everybody else,” he says.

The top brass peppered Freese and Arvan with tough, detailed questions about heat, sealing, flow, packaging, manufacturing and costs.

The key question: Would this design really work? After all, the design broke many of the rules in GM's engine design handbook.

Freese, 39, executive director of GM's diesel powertrain engineering, and Arvan, 41, chief engineer for the GM Duramax diesel engines, already had grappled with many of those questions. In some cases, though, they needed more studies.

The more he heard, the more GM Powertrain boss Tom Stephens was intrigued. He told Freese and Arvan to do more research to verify their design.

Using GM's supercomputers, Freese, Arvan, and other engineers watched the engine take shape on screen, looking inside the virtual engine as it ran. They were measuring such things as heat, flow and stress.

Never before
The data were critical, because nobody had seen a production engine like this before. The proposed engine's design reverses the flow of air and exhaust gases going in and out of the cylinder heads.

On standard V-8 engines, fuel and air enter on the side of the cylinder heads facing the inner part of the “V.” The exhaust gases exit on the V's outside.

Savings: Up to $600
The new design could shave $350 to $600 off the cost of producing the engine, Hall estimates.

Given diesel's high costs, that is huge. “Day one, when you start a diesel program, you are already in cost trouble,” says Arvan.

The savings, Hall says, come in a number of areas. First, GM will save money by eliminating the two dozen parts. GM won't have to buy those parts from suppliers, or design, test and validate them. GM also should save money on the assembly line. With fewer parts, the engine can be built faster, with less labor.

GM won't say how much it will save per engine, but Freese acknowledges the savings will be big. Others estimate that GM's savings per engine in parts costs alone will likely be around $100.

The compact design also solved a space problem. GM wanted a V-8 diesel that could fit in the same space as the small-block V-8 gasoline engines in the Chevrolet Silverado/GMC Sierra pickups, and in the Chevrolet Tahoe/GMC Yukon SUVs. Narrower than a regular diesel of the same displacement, the new engine fit.

For all of its size, weight and cost advantages, it was the engine's performance that finally mattered.

Less than a year after Freese and Arvan's pitch, GM CEO Rick Wagoner, Vice Chairman Bob Lutz and Stephens test drove the first running versions of the engine at GM's sprawling Milford, Mich., proving grounds.

Emerging from a test dark-blue Buick Rainier engineering mule, the three senior executives were amazed at how smooth, quiet and powerful the new diesel engine ran.

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Source: Automotive News  

Errrr... I always cringe when I hear automakers talk about making changes to an already successful, durable engine. The old adage "If it a'int broke, don't fix it" comes to mind.

I was very upset when I learned that my beloved 7.3L Powerstroke would be replaced by a new 6.0 L Powerstroke that, according to claims, was lighter and more powerful than the  previous 7.3. Well, need I say more? . While the 7.3 was bulletproof, the 6.0 was bullet-riddled with problems- mostly severe. A massive recall resulted along with a dispute between two previously close partners, Ford and Navistar. The rest is history. The 6.0 is now obsolete, replaced by the better 6.4L. However, the 7.3L Powerstroke will always hold special place in my heart.