GM Powertrain's Ecotec inline four-cylinder engine family – GM’s first truly "global" engine design when it was launched in 2000 – adds a new, larger-displacement 2.4-liter variant for 2005, as well as significant new technology upgrades that make the modular Ecotec engines class leaders in terms of power, torque and refinement.

The well-known Ecotec 2.2-liter is joined for the 2005 model year by an all-new, larger-displacement Ecotec 2.4-liter with variable valve timing, with first usage in the 2005 Chevrolet Cobalt. And for the 2004 model year, a potent Ecotec supercharged 2.0-liter was launched to power the Saturn Ion Red Line. Although each engine has distinct differences and personality, all share the Ecotec family's outstanding basic architecture:

• All-aluminum construction Dual overhead camshafts (DOHC) and four valves per cylinder
• Twin counter-rotating balance shafts to cancel the second-order shaking forces that cause vibration in four-cylinder inline engines
• Low-friction, roller-finger follower valvetrain with hydraulic lash adjusters
• Zero-maintenance chain camshaft drive
• Extremely compact dimensions and low mass
• Direct mounting of all ancillaries to the engine structure to eliminate common sources of noise, vibration and harshness
• No routine maintenance apart from oil/oil filter changes
• Catalyst located close to the exhaust manifold to speed catalyst "light-off" and reduce hydrocarbon emissions Innovative cast-in oil filter housing eliminates crawling under the car to perform filter changes. The design also eliminates throw-away oil-filter "cans" that retain excess used oil that typically ends up in landfills

"Ecotec is one of the highest-volume four-cylinder engine programs in the world," said Jay Subhedar, Ecotec global four-cylinder engine assistant chief engineer. "Its efficiency and reliability are well-established – now we are adding a new variant to prove the Ecotec architecture's performance potential."

All-New Ecotec 2.4-liter: Torque-Rich Driving Experience

The 2005 Cobalt features an optional new 2.4-liter Ecotec that delivers a demonstrable horsepower and torque upgrade over the standard Ecotec 2.2-liter. Equipped with variable valve timing and a host of new features and improvements, the Ecotec 2.4-liter generates an impressive 170 horsepower (estimated prior to final production figures) at 6000 rpm and 90 percent of the 170 lb.-ft. peak torque over a wide 2400-5600 engine rpm range.

Torque is the engine characteristic that satisfies most drivers in most driving situations. The Ecotec 2.4-liter engine's expected 170 lb.-ft. of torque surpasses many other normally aspirated, same-displacement four-cylinder engine offered in the United States (based on Ward's 2003 model-year market data), while the infinitely variable camshaft phasing ensures the new engine delivers 90 percent of its peak torque beginning at just 2400 rpm.

Bottom line: more torque, more of the time, than any comparable four-cylinder engine from any of the competition. But the Ecotec 2.4-liter story isn't just about churning out class-leading torque. Numerous component and design upgrades ensure the newest member of the Ecotec family backs up its reputation for unsurpassed durability, efficiency and cost of ownership. The new Ecotec 2.4-liter will be built at Spring Hill, Tennessee.

Supercharged Ecotec: Fast and Furious at a Competitive Price

A significant new variant of the original Ecotec 2.2-liter engine is the Ecotec 2.0-liter supercharged, available for the first time in the high-performance 2004 Saturn Ion Red Line edition. The Ecotec 2.0-liter supercharged slams out a formidable 205 horsepower at 5600 rpm and 200 lb.-ft. of torque at 4400 rpm. Development of this highest-performance Ecotec variant (LSJ) leveraged several areas of GM Powertrain expertise, including GM Racing, GM High Performance Vehicle Operations (HPVO) and charged intake specialist Saab, a wholly owned GM subsidiary.

To attain the durability targets GM Powertrain engineers require of every GM engine, the Ecotec supercharged 2.0-liter received upgraded components in critical stress areas. Experience in the tortuous crucible of the National Hot Rod Association's Championship Drag Racing series – where the Ecotec has developed a "bullet-proof" reputation as a formidable powerplant for front-wheel drive dragsters – told engineers where the production-car supercharged Ecotec would most benefit from heavy-duty components. Additionally, the Ecotec supercharged 2.0-liter borrows knowledge gleaned by Saab engineers when adapting the Ecotec to the demanding specifications of high-output turbocharged engines.

At the heart of the Ecotec supercharged 2.0-liter is an Eaton M62 helical roots-type supercharger. Engineers selected the Eaton unit because of its optimum response characteristics and ease of "packaging" with the Ecotec architecture, according to Grant Brady, design system engineer. Maximum supercharger boost pressure is 12 pounds, and the system includes an air-to-water intercooler to increase intake-charge density, which in turn enhances power and reduces a supercharged engine's propensity to "knock" at high boost levels.

The Ecotec supercharged 2.0-liter also is fitted with numerous upgraded components to assure reliability and superior performance:

• Sodium-filled exhaust valves more effectively dissipate exhaust heat
• A forged-steel crankshaft with induction-hardened fillets and four counterweights
• Oil jets cool the underside of each piston with a continuous oil bath
• A block-mounted oil cooler and a higher-capacity seven-quart sump
• Forged steel connecting rods with a larger I-beam section
• Heavy duty pistons with a 23-mm piston pin for increased bearing surface
• High-capacity cooling system with larger radiator core and larger dual cooling fans
• Coil-on-plug ignition ensures optimum spark under all operating conditions
• High-flow, 2.5-inch exhaust system – an almost 50-percent increase – with increased muffler volume reduces power-robbing exhaust backpressure

The Ecotec supercharged 2.0-liter also employs electronic throttle control (ETC), which eliminates the cable connection between the accelerator pedal and the engine throttle. "Electronic throttle control is an elegant and effective way to add a higher degree of control for the driver," said Subhedar. "The precision ETC offered is critical for delivering the kind of performance, fuel economy and minimal emissions we expect from this very high performance engine."

As with the Ecotec 2.2-liter and new Ecotec 2.4-liter, the 2.0-liter supercharged version employs dual balance shafts, fitted in the engine block, to cancel secondary vertical shaking forces produced by all inline four-cylinder engines. The counter-rotating balance shafts, which rotate at twice the speed of the crankshaft, were a feature GM Powertrain engineers specified from the onset to ensure the Ecotec architecture delivered a high level of refinement and reduced vibration throughout its speed range.

The Ecotec supercharged 2.0-liter engine is built exclusively at Fiat-GM Powertrain's Kaiserslautern, Germany, engine plant.

Ecotec 2.2-Liter: The Original is Better Than Ever

The Ecotec 2.2-liter was the first production version of GM Powertrain's Ecotec modular all-aluminum four-cylinder engine architecture. The Ecotec 2.2-liter currently powers nearly a dozen GM and Opel models in North America and Europe, and will be available in the 2005 Cobalt.

The Ecotec 2.2-liter is expected to produce better than 140 horsepower at 5600 rpm and 150 lb.-ft. of torque at 4000 rpm in the new Cobalt. Launched for the 2000 model year, the 2.2-liter Ecotec was developed to give GM a fully contemporary all-aluminum four-cylinder engine architecture with a worldwide application base that would allow the gradual consolidation of seven different GM four-cylinder engine families.

One of the Ecotec engine program's most significant contributions is in the manufacturing sector. The engine's unique "lost-foam" aluminum casting method is environmentally benign: almost 100 percent of the sand used in the casting process can be recycled. The lost foam method also has another benefit: it allows thinner cross-section in many areas and cast-in features, which eases the job of machining the engine blocks and cylinder heads. The Ecotec 2.2-liter is built in Tonawanda, N.Y.; Spring Hill, Tennessee; and Kaiserslautern, Germany.

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Source: General Motors