GM Calls Next-Gen V-8 Engine ‘Technological Masterpiece’

PONTIAC, MI – General Motors introduces today its next-generation V-8 engine, a technology-laden powerplant promising 0-60 mph (97 km/h) performance in less than 4 seconds and fuel economy upwards of 26 mpg (9.0 L/100 km) in the soon-to-be-released ’14 Chevrolet Corvette.

Key elements of the fifth-generation small-block V-8 include direct injection, cylinder deactivation and continuously variable valve timing.

Preliminary specifications call for 450 hp at 6,000 rpm and 450 lb.-ft. (610 Nm) of torque at 4,000 rpm from the 6.2L engine, which retains the same displacement of the Gen4 edition but sees both output measures increase significantly.

It is 40 lbs. (18 kg) lighter than its key competitor, the 4.4L twin-turbo V-8 from BMW, and 4 ins. (102 mm) shorter in height. Those dimensions greatly aid the Corvette’s enviable balance and handling.

GM emphasizes the output figures are preliminary, a hint the numbers could increase closer to the introduction of the redesigned Corvette next year as the cat-and-mouse game between the Detroit Three over the horsepower crown continues.

The auto maker also boasts of the new engine’s low-end torque, saying as much as 420 lb.-ft. (569 Nm) will come below 4,000 rpm. That output is on par with the larger 7.0L V-8 in the Corvette Z06.

“You can look forward to another generation of ground-pounding, American thunder,” Corvette Chief Engineer Tadge Juechter tells journalists during an event at GM Powertrain headquarters here.

GM will unveil the hotly anticipated, next-generation Corvette in January at the Detroit auto show. This year marks the Corvette’s 60^th anniversary, and 57 of those years included a GM small-block, long known for its compact size and high output. The engine also will see duty in other GM sports cars, as well as pickups and SUVs.

Gen 5 small-block V-8 program manager Jordan Lee says the key output and efficiency enabler is an advanced combustion system taking full advantage of the engine’s core technologies.

“It was very difficult to do,” Lee says. “Very difficult to do correctly, but done right you extract every bit of energy for maximum power and fuel efficiency.”

Lee says the new combustion system ate more than 6 million of the 10 million hours of the engine’s computational analysis. It also took two years of the program’s five years of development.

“That’s a lot of analytical horsepower,” Lee says.

The new combustion system, which includes new cylinder-head and piston designs, provides the engine with a lofty 11:5.1 compression ratio enabling high levels of efficiency.

It marks the industry’s first overhead-valve gasoline engine with direct injection, leading to a highly complex swirling process of the air and fuel mixture inside the cylinders to achieve optimal combustion. It is the first Corvette with cylinder deactivation.

The combustion system design also commanded extensive research into the placement of injectors in relation to the spark plugs; the size of the intake and exhaust valves, as well as their angle inside the cylinder head; size and volume of the chamber; and configuration of the piston head, which GM says is crucial to support direct injection.

Another significant element of the Gen 5 engine’s combustion system is placement of the intake and exhaust valve, which are reversed compared with the previous generation. The change enables a straighter path for air into the combustion chamber and again improves efficiency.

“Our objective for the development of the all-new LT1 was to raise the bar for performance-car engines,” Mary Barra, senior vice president-global product development at GM says in a statement.

“We feel that we have achieved that by delivering a true technological masterpiece that seamlessly integrates a suite of advanced technologies that can only be found on a handful of engines in the world.”

GM last redesigned the iconic small-block V-8 in 2004, when it rolled out its redesigned fullsize trucks.

Dean Guard, who leads GM engine program executions, says the Gen5 small-block V-8 will not be the last-generation GM V-8, despite future U.S. fuel-economy rules calling for 54.5 mpg (4.3 L/100 km) by 2025.

“We intend to keep it around for the foreseeable future, and we see far into the future,” Guard tells WardsAuto, noting demand for the engines remains strong evidenced by 8 million in GM trucks on the road today.

“We’ve been at this a long time, and the company is behind us on the V-8 in a 54.5 mpg world,” he says.

The Corvette’s Gen5 small-block will be built at GM’s Tonawanda, NY, engine plant. The facility received a $400 million investment to support the work, part of a larger, $890 million investment for manufacturing the engine.

– with Tom Murphy

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