The engine block was developed with math-based tools and data acquired in GM's racing programs, and provides a light, rigid foundation for an impressively smooth engine. Its deep-skirt design helps maximize strength and minimize vibration. The bulkheads accommodate six-bolt, cross-bolted main-bearing caps that limit crank flex and stiffen the engine's structure. A structural oil pan further stiffens the powertrain. Along with the rigid block, the engine's rotating assembly was designed for optimal strength and duration complemented by features designed to make the LC9 quiet and smooth.

The LC9 5.3L also features a heavy-duty timing chain developed expressly for quiet operation. The chain, which connects the camshaft and crankshaft, is validated for 200,000 miles of operation and fitted with a leaf-spring-type dampener.

The 5.3L's cylinder heads feature "cathedral"-shaped intake ports that promote exceptional airflow. They support great airflow at higher rpm for a broader horsepower band, along with strong, low-rpm torque. The intake ports that feed the combustion chambers, as well as the D-shaped exhaust ports, are designed for excellent high-rpm airflow.

The 5.3L features variable valve timing, maximizing engine performance for given demands and conditions. At idle, for example, the cam is at the full advanced position, allowing exceptionally smooth idling. Under other conditions, the phaser adjusts to deliver optimal valve timing for performance, drivability and fuel economy. At high rpm's it may retard timing to maximize airflow through the engine and increase horsepower. At low rpm's it can advance timing to increase torque. Under light loads, it can retard timing at all engine speeds to improve fuel economy.

E85 is a clean-burning, domestically produced fuel composed of 85 percent ethanol alcohol and 15 percent gasoline. Ethanol is renewable and produces fewer greenhouse gases during the combustion process. It can be produced from various feed stocks, including corn and wheat stalks, forestry and agricultural waste and even municipal waste.

GM's Active Fuel Management technology increases fuel economy approximately 6 percent under the federal government's required testing procedure and potentially more in certain real-world driving conditions. AFM temporarily deactivates four of the LC9's cylinders under light load conditions and seamlessly reactivates them when the driver demands full power. The transition takes less than 20 milliseconds, and is virtually indiscernible to most drivers.

GM has led the industry in applying electronic throttle control (ETC). With ETC, there is no mechanical link between the accelerator pedal and the throttle body. A sensor at the pedal measures pedal angle and sends a signal to the engine control module (ECM), which in turn directs an electric motor to open the throttle at the appropriate rate and angle. ETC delivers a number of benefits to the customer.

The exhaust manifolds were developed to improve durability and sealing and reduce operational noise. Cast nodular iron was the material of choice for its basic durability and excellent heat-management properties. The manifolds are fitted with new triple-layer heat shields fabricated from stainless steel and insulating material. The shields limit heat transfer from the engine to the engine bay, allowing the 5.3L to reach optimal operating temperature more quickly, yet reducing heat in the engine compartment once that temperature is achieved.

The LC9 has an advanced 58X crankshaft position encoder to ensure that ignition timing is accurate throughout its operating range. The new 58X crankshaft ring and sensor provide more immediate, accurate information on the crankshaft's position during rotation. This allows the engine control module to adjust ignition timing with greater precision, which optimizes performance and economy. Engine starting is also more consistent in all operating conditions.

The Ecotec 2.4L (LE9) features pistons with a slight barrel shape, which helps smooth the glide through the cylinders and reduce lateral movement. It results in quieter – especially on cold starts – and smoother operation. The Ecotec 2.4L's pistons use lightweight aluminum pistons, for less reciprocating mass inside the engine that enhances efficiency, decreases vibration and bolsters the feeling of performance as rpm increases.

Overhead cams are the most direct, efficient means of operating the valves, while four valves per cylinder increase airflow in and out of the engine. Continuously variable valve timing optimizes the engine's turbocharging system by adjusting valve timing at lower rpm for improved turbo response and greater torque delivery.

Cam phasing allows an outstanding balance of smooth torque delivery over a broad rpm range, high specific output and good specific fuel consumption. Cam phasing also provides another effective tool for controlling exhaust emissions.

The Ecotec 2.4L camshafts feature 4X timing reluctors with digital sensors. This state-of-the-art control system allows the ECM to accurately measure and adjust valve timing, with consistent performance over the engine's anticipated useful life.

GM has led the industry in applying electronic throttle control (ETC). With ETC, there is no mechanical link between the accelerator pedal and the throttle body. A sensor at the pedal measures pedal angle and sends a signal to the engine control module (ECM), which in turn directs an electric motor to open the throttle at the appropriate rate and angle.

E85 is a clean-burning, domestically produced alternative fuel, composed of 85 percent ethanol alcohol and 15 percent gasoline. Ethanol is renewable, biodegradable and produces fewer greenhouse gases in the combustion process. It can be produced from various feed stocks, including corn and wheat stalks, forestry and agricultural waste and even municipal waste.

The engine front covers incorporate a more efficient "goosehead"-port oil pump design, which reduces cavitation at higher engine speeds and results in a measurable reduction in noise, especially in cold-start and drive-away operation. The oil pump also includes a pressure-balanced oil relief valve, further improving the durability and reliability of the lubrication system, as well as a lower friction crank seal.

Routine maintenance with the Ecotec 2.4L is limited to oil and filter changes; and with a paper filter replacement cartridge those are made as easy as possible. GM's industry-leading Oil Life System determines oil-change intervals according to real-world operation rather than a predetermined mileage interval.

The Ecotec 2.4L's sand-cast cylinder provides excellent structural support, as well as enabling greater control of noise, vibration and harshness.

The main bearing bulkheads, which support the crank bearing, as well as the cylinder bore walls, have been significantly strengthened to support increased engine loads.

The Ecotec 2.4L's pistons use lightweight aluminum pistons, for less reciprocating mass inside the engine that enhances efficiency, decreases vibration and bolsters the feeling of performance as rpm increases. Each piston has its own directed jet that sprays oil toward its skirt, coating its underside and the cylinder wall with an additional layer of lubricant. The extra lubrication cools the pistons, reducing friction and operational noise, while also bolstering the engine's durability.

The Ecotec 2.4L has a SPM 319 aluminum cylinder head that is cast with advanced semi-permanent mold technology. This provides excellent strength, reduced machining and optimal port flow. The cylinder head is designed specifically for direct injection into each combustion chamber and includes premium valve seat, valve guide and valve materials. The cylinder head also has integral cast oil passages that feed a set of internal oil control valves that activate cam phasers, enabling variable valve timing.

Overhead cams are the most direct, efficient means of operating the valves, while four valves per cylinder increase airflow in and out of the engine. Continuously variable valve timing optimizes the engine's turbocharging system by adjusting valve timing at lower rpm for improved turbo response and greater torque delivery

Cam phasing allows an outstanding balance of smooth torque delivery over a broad rpm range, high specific output and good specific fuel consumption. Cam phasing also provides another effective tool for controlling exhaust emissions.

Direct injection moves the point where fuel feeds into an engine closer to the point where it ignites, enabling greater combustion efficiency. Direct injection also reduces emissions, particularly cold-start emissions, by about 25 percent.

With direct injection, the higher compression ratio is possible because of a cooling effect as the injected fuel vaporizes in the combustion chamber. This reduces the charge temperature and lessens the likelihood of spark knock. The direct injection fuel injectors have been developed to withstand the greater heat and pressure inside the combustion chamber and also feature multiple outlets for best injection control.

A high-pressure, cam-driven pump provides the fuel pressure required of the direct injection system in the Ecotec 2.4L. The engine-mounted fuel pump is augmented by a conventional electrically operated supply pump in the fuel tank.

Engine block and cylinder heads are cast from A319 aluminum alloy. This aluminum-intensive construction means less weight and greater efficiency than conventional cast-iron engines – and less weight translates to improved vehicle fuel economy.

Direct injection moves the point where fuel feeds into an engine closer to the point where it ignites, enabling greater combustion efficiency. It fosters a more complete burn of the fuel in the air-fuel mixture, and it operates at lower temperature than conventional port injection.

Four-valves-per-cylinder with inverted-tooth chain cam drive contributes to the smoothness and high output of the 3.0L V-6. Overhead cams are the most direct, efficient means of operating the valves, while four valves per cylinder increase airflow in and out of the engine.

Variable valve timing (VVT), or cam phasing, helps the 3.0L V-6 deliver optimal performance, efficiency and emissions. It allows linear delivery of torque, with near-peak levels over a broad rpm range, and high specific output (horsepower per liter of displacement) without sacrificing overall engine response, or driveability.

The upper intake manifold for the 3.0L V-6 is made from composite material and provides mass savings over an aluminum manifold, with a carefully designed structure that helps ensure quiet engine operation.

The cam covers are made of thermoset, glass-filled polyester composite, a material that weighs less than the cast aluminum used on most premium engines and more effectively dampens noise.

The 3.0L engine features integrated exhaust manifolds with the cylinder heads, eliminating the need for separate exhaust manifolds. The benefits include reducing the mass of the engine for improved fuel economy and faster catalytic converter light off, resulting in reduced emissions.

The 3.6L V-6 VVT's engine block is cast from A319 aluminum alloy. This aluminum-intensive construction means less weight and greater efficiency than conventional cast-iron engines – and less weight translates to improved vehicle fuel economy. The sand-mold-cast block features strong cast-in iron bore liners, six-bolt main caps, and inter-bay breather vents. A cast aluminum oil pan is stiffened to improve powertrain rigidity and reduce vehicle vibration.

The crankshaft is manufactured from forged steel, while the connecting rods are made of powdered metal that features a higher ratio of copper, which makes them stronger and enables them to be lighter.

The V-6 VVT engine family was developed with pressure-actuated oil squirters in all applications. The jets reduce piston temperature, which in turn allows the engine to produce more power without reducing long-term durability.

The LFX's new cylinder head design has a revised intake port design that enhances airflow to the combustion chambers. Larger-diameter intake valves are used in the heads and work in conjunction with new, longer-duration intake camshafts to provide the engine's boost in horsepower. By using larger valves and holding them open longer, more of the air is pulled into the combustion chamber, for a more powerful combustion. The exhaust manifold is incorporated with the cylinder head, which saves weight, reduces complexity and helps promote a quicker light off of the catalytic converter, which further helps reduce emissions.

Direct injection moves the point where fuel feeds into an engine closer to the point where it ignites, enabling greater combustion efficiency. It fosters a more complete burn of the fuel in the air-fuel mixture, and it operates at a lower temperature than conventional port injection. That allows the mixture to be leaner (less fuel and more air), so less fuel is required to produce the equivalent horsepower of a conventional, port injection fuel system. Direct injection also delivers reduced emissions, particularly cold-start emissions, which are cut by about 25 percent.

E85 is a clean-burning, domestically produced alternative fuel composed of 85 percent ethanol alcohol and 15 percent gasoline. Ethanol is renewable and produces fewer greenhouse gas emissions in the combustion process. It can be produced from various feed stocks, including corn and wheat stalks, forestry and agricultural waste and even municipal waste.

Four-valves-per-cylinder with inverted-tooth chain cam drive contributes to the smoothness and high output of the LFX. The engine incorporates a timing chain with an inverted tooth design. These smaller links engage at a lower impact speed, which decreases the noise generated. In conjunction with the smaller pitch chain, the number of teeth on the sprockets are increased, which increases the meshing frequency and further reduces noise and vibration.

Four valves per cylinder and a silent chain valvetrain contribute to both smoothness and high output. Four-cam phasing changes the timing of valve operation as operating conditions such as rpm and engine load vary.

Variable valve timing (VVT), or cam phasing, helps the LFX deliver optimal performance and efficiency, and reduced emissions. It allows linear delivery of torque, with near-peak levels over a broad rpm range, and high specific output (horsepower per liter of displacement) without sacrificing overall engine response, or driveability. The system changes valve timing on the fly, maximizing engine performance for a variety of operating conditions. At idle, for example, the cam is at the full advanced position, enabling exceptionally smooth idle quality. Under other operating demands, cam phasing adjusts to deliver optimal valve timing for performance, driveability and fuel economy. At high rpm it might retard timing to maximize airflow through the engine and increase horsepower. At low rpm it can advance timing to increase torque. Under light-load driving it can retard timing at all engine speeds to improve fuel economy.

The upper intake manifold for the LFX is made from composite material and provides mass savings over an aluminum manifold, with a carefully designed structure that helps ensure quiet engine operation. The surfaces on the cam covers are shaped to limit the broadcasting of undesirable noise, and the covers use isolating perimeter gaskets, as well as isolating radial lips around the tubes that accommodate the spark plugs. These effectively de-couple the covers from vibration generated in the block and engine during combustion. Acoustic dampening has also been added for additional NVH improvements.

Additional changes incorporated in the LFX deliver greater refinement, quietness and durability, starting with revisions to the front cover. It was redesigned with additional support ribs on the backside and an additional fastener to improve noise and vibration characteristics. The cylinder block is modified slightly to accommodate the front cover's additional fastener.

Also, the camshafts feature new saddle-type caps for improved durability. Finally, the throttle body is updated with a new, digital throttle position feature that eliminates a previous mechanical contact for more trouble-free operation.

The Ecotec 2.0L turbo sand-cast cylinder block is a superior refinement of previous Ecotec engine block castings. It is dimensionally similar with previous Ecotec turbo block variants, while providing improved structural support, as well as enabling greater control of noise, vibration and harshness.

The Ecotec 2.0L turbo's A356 aluminum cylinder head is cast using a Rotocast process for high strength, reduced machining and improved port flow. The head is also designed specifically for direct injection. The head uses stainless steel intake valves that are nitrided for improved durability and undercut to improve flow and reduce weight. The exhaust valves have sodium-filled stems that promote valve cooling.

Performance was the priority with the Ecotec 2.0L turbo, so the exhaust manifold mounted to the cylinder head is made of cast stainless steel. It is extremely durable and delivers exceptional airflow qualities.

Overhead cams are the most direct, efficient means of operating the valves, while four valves per cylinder increase airflow in and out of the engine. Continuously variable valve timing optimizes the engine's turbocharging system by adjusting valve timing at lower rpm for improved turbo response and greater torque delivery.

Cam phasing allows an outstanding balance of smooth torque delivery over a broad rpm range, high specific output and good specific fuel consumption. Cam phasing also provides another effective tool for controlling exhaust emissions.

Direct injection moves the point where fuel feeds into an engine closer to the point where it ignites, enabling greater combustion efficiency. Direct injection also reduces emissions, particularly cold-start emissions, by about 25 percent.

With direct injection, the higher compression ratio is possible because of a cooling effect as the injected fuel vaporizes in the combustion chamber. This reduces the charge temperature and lessens the likelihood of spark knock. The direct injection fuel injectors have been developed to withstand the greater heat and pressure inside the combustion chamber and also feature multiple outlets for best injection control.

A high-pressure, cam-driven pump provides the fuel pressure required of the Ecotec 2.0L turbo's direct injection system. The engine-mounted fuel pump is augmented by a conventional electrically operated supply pump in the fuel tank.

An electronically controlled turbocharger with a unique twin-scroll design is used to increase power in the Ecotec 2.0L turbo. The turbocharger generates maximum boost of about 20 psi. Because direct injection cools the intake process compared to port injection, it allows the Ecotec 2.0L turbo to safely operate at higher boost and a relatively higher compression than a conventional turbo engine, increasing both output and efficiency.

An intake charge cooler enhances the power-increasing benefits of the turbocharging system. The Ecotec 2.0L turbo's air-to-air intercooler draws fresh air through a heat exchanger to reduce the temperature of compressed air that's forced through the intake system by the turbocharger.

A cam-driven vacuum pump ensures the availability of vacuum under all conditions, especially under boost, when the engine produces the opposite of vacuum. The pump is mounted at the rear of the cylinder head and is driven by the exhaust camshaft via a flexible coupling.

The 3.6L V-6 VVT's engine block and cylinder heads are cast from A319 aluminum alloy. This aluminum-intensive construction means less weight and greater efficiency than conventional cast-iron engines – and less weight translates to improved vehicle fuel economy. The sand-mold-cast block features strong cast-in iron bore liners, six-bolt main caps, and inter-bay breather vents.

The crankshaft is manufactured from forged steel and the connecting rods are a sinter forging, as used on other 3.6L V-6 VVT engines. The pistons are made of lightweight cast aluminum and feature a friction-reducing polymer coating on the skirts, as well as fully floating wrist pins, which also help reduce friction. Less weight in the pistons means less reciprocating mass in the engine, which in turn means less inertia and greater operating efficiency.

The V-6 VVT engine family was developed with pressure-actuated oil squirters in all applications. The jets reduce piston temperature, which in turn allows the engine to produce more power without reducing long-term durability.

Direct injection moves the point where fuel feeds into an engine closer to the point where it ignites, enabling greater combustion efficiency. It fosters a more complete burn of the fuel in the air-fuel mixture, and it operates at a lower temperature than conventional port injection. That allows the mixture to be leaner (less fuel and more air), so less fuel is required to produce the equivalent horsepower of a conventional, port injection fuel system. Direct injection also delivers reduced emissions, particularly cold-start emissions, which are cut by about 25 percent.

An engine-driven high-pressure pump supplies fuel to the injectors to overcome the higher pressures inside the combustion chamber, as well as supply the multiple injection points of the direct injection nozzles. This variable-pressure high-pressure pump feeds a high-strength stainless steel fuel rail attached to the injectors.

Four-valves-per-cylinder with inverted-tooth chain cam drive contributes to the smoothness and high output of the LFX. The engine incorporates a timing chain with an inverted tooth design. These smaller links engage at a lower impact speed, which decreases the noise generated. In conjunction with the smaller pitch chain, the number of teeth on the sprockets are increased, which increases the meshing frequency and further reduces noise and vibration.

Variable valve timing (VVT), or cam phasing, helps the 3.6L V-6 deliver optimal performance and efficiency, and reduced emissions. It allows linear delivery of torque, with near-peak levels over a broad rpm range, and high specific output (horsepower per liter of displacement) without sacrificing overall engine response, or driveability.

The upper intake manifold for the 3.6L V-6 is made from composite material and provides mass savings over an aluminum manifold, with a carefully designed structure that helps ensure quiet engine operation.

The engine block was developed with math-based tools and data acquired in GM's racing programs, and provides a light, rigid foundation for an impressively smooth engine. Its deep-skirt design helps maximize strength and minimize vibration. The bulkheads accommodate six-bolt, cross-bolted main-bearing caps that limit crank flex and stiffen the engine's structure. A structural oil pan further stiffens the powertrain. Along with the rigid block, the engine's rotating assembly was designed for optimal strength and duration complemented by features designed to make the LMF quiet and smooth.

The LMF 5.3L also features a heavy-duty timing chain developed expressly for quiet operation. The chain, which connects the camshaft and crankshaft, is validated for 200,000 miles of operation and fitted with a leaf-spring-type dampener.

The 5.3L's cylinder heads feature "cathedral"-shaped intake ports that promote exceptional airflow. They support great airflow at higher rpm for a broader horsepower band, along with strong, low-rpm torque. Large, 2.000-inch intake and 1.550-inch exhaust valves are used in the 356-T6 aluminum alloy heads, but are made of specific material that supports the load and durability requirements of a truck engine. The intake ports that feed the combustion chambers, as well as the D-shaped exhaust ports, are designed for excellent high-rpm airflow.

The 5.3L features variable valve timing, maximizing engine performance for given demands and conditions. At idle, for example, the cam is at the full advanced position, allowing exceptionally smooth idling. Under other conditions, the phaser adjusts to deliver optimal valve timing for performance, drivability and fuel economy. At high rpm's it may retard timing to maximize airflow through the engine and increase horsepower. At low rpm's it can advance timing to increase torque. Under light loads, it can retard timing at all engine speeds to improve fuel economy.

E85 is a clean-burning alternative fuel made in the United States, composed of 85 percent ethanol alcohol and 15 percent gasoline. Ethanol is biodegradable and doesn't contaminate the water supply. It can be produced from various feed stocks, including corn and wheat stalks, forestry and agricultural waste and even municipal waste.

GM has led the industry in applying electronic throttle control (ETC). With ETC, there is no mechanical link between the accelerator pedal and the throttle body. A sensor at the pedal measures pedal angle and sends a signal to the engine control module (ECM), which in turn directs an electric motor to open the throttle at the appropriate rate and angle. ETC delivers a number of benefits to the customer.

The exhaust manifolds were developed to improve durability and sealing and reduce operational noise. Cast nodular iron was the material of choice for its basic durability and excellent heat-management properties. The manifolds are fitted with new triple-layer heat shields fabricated from stainless steel and insulating material. The shields limit heat transfer from the engine to the engine bay, allowing the 5.3L to reach optimal operating temperature more quickly, yet reducing heat in the engine compartment once that temperature is achieved.

The LMF has an advanced 58X crankshaft position encoder to ensure that ignition timing is accurate throughout its operating range. The new 58X crankshaft ring and sensor provide more immediate, accurate information on the crankshaft's position during rotation. This allows the engine control module to adjust ignition timing with greater precision, which optimizes performance and economy. Engine starting is also more consistent in all operating conditions.

The engine block was developed with math-based tools and data acquired in GM's racing programs, and provides a light, rigid foundation for an impressively smooth engine. Its deep-skirt design helps maximize strength and minimize vibration. The bulkheads accommodate six-bolt, cross-bolted main-bearing caps that limit crank flex and stiffen the engine's structure. A structural oil pan further stiffens the powertrain. Along with the rigid block, the engine's rotating assembly was designed for optimal strength and duration complemented by features designed to make the LMG quiet and smooth.

The LMG 5.3L also features a heavy-duty timing chain developed expressly for quiet operation. The chain, which connects the camshaft and crankshaft, is validated for 200,000 miles of operation and fitted with a leaf-spring-type dampener.

The 5.3L's cylinder heads feature "cathedral"-shaped intake ports that promote exceptional airflow. They support great airflow at higher rpm for a broader horsepower band, along with strong, low-rpm torque.

Large, 2.000-inch intake and 1.550-inch exhaust valves are used in the 356-T6 aluminum alloy heads, but are made of specific material that supports the load and durability requirements of a truck engine. The intake ports that feed the combustion chambers, as well as the D-shaped exhaust ports, are designed for excellent high-rpm airflow.

The 5.3L features variable valve timing, maximizing engine performance for given demands and conditions. At idle, for example, the cam is at the full advanced position, allowing exceptionally smooth idling. Under other conditions, the phaser adjusts to deliver optimal valve timing for performance, drivability and fuel economy. At high rpm's it may retard timing to maximize airflow through the engine and increase horsepower. At low rpm's it can advance timing to increase torque. Under light loads, it can retard timing at all engine speeds to improve fuel economy.

E85 is a clean-burning, domestically produced fuel composed of 85 percent ethanol alcohol and 15 percent gasoline. Ethanol is renewable and produces fewer greenhouse gases in the combustion process. It can be produced from various feed stocks, including corn and wheat stalks, forestry and agricultural waste and even municipal waste.

GM's Active Fuel Management technology increases fuel economy approximately 6 percent under the federal government's required testing procedure and potentially more in certain real-world driving conditions. AFM temporarily deactivates four of the LMG's cylinders under light load conditions and seamlessly reactivates them when the driver demands full power. The transition takes less than 20 milliseconds, and is virtually indiscernible to most drivers.

GM has led the industry in applying electronic throttle control (ETC). With ETC, there is no mechanical link between the accelerator pedal and the throttle body. A sensor at the pedal measures pedal angle and sends a signal to the engine control module (ECM), which in turn directs an electric motor to open the throttle at the appropriate rate and angle. ETC delivers a number of benefits to the customer.

The exhaust manifolds were developed to improve durability and sealing and reduce operational noise. Cast nodular iron was the material of choice for its basic durability and excellent heat-management properties. The manifolds are fitted with new triple-layer heat shields fabricated from stainless steel and insulating material. The shields limit heat transfer from the engine to the engine bay, allowing the 5.3L to reach optimal operating temperature more quickly, yet reducing heat in the engine compartment once that temperature is achieved.

The LMG has an advanced 58X crankshaft position encoder to ensure that ignition timing is accurate throughout its operating range. The new 58X crankshaft ring and sensor provide more immediate, accurate information on the crankshaft's position during rotation. This allows the engine control module to adjust ignition timing with greater precision, which optimizes performance and economy. Engine starting is also more consistent in all operating conditions.

The Duramax block features casting enhanced to support smoother and quieter engine operation. It uses a strong cast iron foundation known for its durability, with induction-hardened cylinder walls and five nodular iron main bearings. A die-cast aluminum lower crankcase strengthens the engine block and serves as the lower engine cover, while also reducing the engine's overall weight.

Working within the cylinder block is a robust rotating assembly that features a forged steel crankshaft, forged steel connecting rods and forged aluminum pistons. The crankshaft is surface-hardened by nitriding, a process widely acknowledged as the most effective means of limiting wear and ensuring durability.

The pistons are redesigned without pin bushings to reduce reciprocating weight, which helps the engine rev quicker and respond more immediately to throttle changes. The connecting rods that are used with the pistons feature a smaller-diameter pin bore on the small end to support the strengthened pistons. Piston-cooling oil jets are located at the bottom of the cylinder bores and spray engine oil on the bottom of the pistons. The extra lubrication cools the pistons, reducing friction and operational noise, while also bolstering the engine's durability.

The Duramax diesel features an aluminum cylinder head design, with six head bolts per cylinder and four valves per cylinder. The aluminum material of the heads helps reduce the engine's overall weight, while the six-bolt design provides exceptional head-clamping strength – a must in a high-compression, turbocharged application.

The Duramax uses a common-rail direct injection fuel system. Piezo injectors allow a more precise metering of the fuel, especially for very small quantities of injected fuel, which leads to a smoother idle and lower combustion noise.

A variable-vane turbocharger is employed on the Duramax 6.6L. With the variable-geometry turbocharger, the engine delivers more power with lower exhaust emissions and no decrease in overall fuel efficiency. The system uses self-adjusting turbine vanes and sophisticated electronic controls to automatically adjust boost pressure and exhaust backpressure.

The Duramax diesel features the latest in emission control technology, making it the cleanest Duramax engine ever produced, with NOx emissions reduced by at least 63 percent in the LML version.

The LML version of the Duramax 6.6L turbo diesel is capable of running on B20 biodiesel, a fuel composed of 20 percent biodiesel and 80 percent conventional diesel. B20 helps lower carbon dioxide emissions and lessens dependence on petroleum. It is a domestically produced, renewable fuel made primarily of plant matter – mostly soybean oil

The Duramax block features casting enhanced to support smoother and quieter engine operation. It uses a strong cast iron foundation known for its durability, with induction-hardened cylinder walls and five nodular iron main bearings. A die-cast aluminum lower crankcase strengthens the engine block and serves as the lower engine cover, while also reducing the engine's overall weight.

Working within the cylinder block is a robust rotating assembly that features a forged steel crankshaft, forged steel connecting rods and forged aluminum pistons. The crankshaft is surface-hardened by nitriding, a process widely acknowledged as the most effective means of limiting wear and ensuring durability.

The pistons are redesigned without pin bushings to reduce reciprocating weight, which helps the engine rev quicker and respond more immediately to throttle changes. The connecting rods that are used with the pistons feature a smaller-diameter pin bore on the small end to support the strengthened pistons. Piston-cooling oil jets are located at the bottom of the cylinder bores and spray engine oil on the bottom of the pistons. The extra lubrication cools the pistons, reducing friction and operational noise, while also bolstering the engine's durability.

The Duramax diesel features an aluminum cylinder head design, with six head bolts per cylinder and four valves per cylinder. The aluminum material of the heads helps reduce the engine's overall weight, while the six-bolt design provides exceptional head-clamping strength – a must in a high-compression, turbocharged application.

The Duramax uses a common-rail direct injection fuel system. Piezo injectors allow a more precise metering of the fuel, especially for very small quantities of injected fuel, which leads to a smoother idle and lower combustion noise.

A variable-vane turbocharger is employed on the Duramax 6.6L. With the variable-geometry turbocharger, the engine delivers more power with lower exhaust emissions and no decrease in overall fuel efficiency. The system uses self-adjusting turbine vanes and sophisticated electronic controls to automatically adjust boost pressure and exhaust backpressure.

The Duramax diesel features the latest in emission control technology, making it the cleanest Duramax engine ever produced, with NOx emissions reduced by at least 63 percent in the LML version.

The LML version of the Duramax 6.6L turbo diesel is capable of running on B20 biodiesel, a fuel composed of 20 percent biodiesel and 80 percent conventional diesel. B20 helps lower carbon dioxide emissions and lessens dependence on petroleum. It is a domestically produced, renewable fuel made primarily of plant matter – mostly soybean oil

The engine block was developed with math-based tools and data acquired in GM's racing programs, and provides a light, rigid foundation for an impressively smooth engine. Its deep-skirt design helps maximize strength and minimize vibration. The bulkheads accommodate six-bolt, cross-bolted main-bearing caps that limit crank flex and stiffen the engine's structure. A structural oil pan further stiffens the powertrain.

Within the LS3 block is a durable rotating assembly that includes a steel crankshaft and connecting rods, as well as high-strength, aluminum-alloy pistons. The flat-top pistons are also lightweight, which enhances high-rpm performance, as they enable the engine to rev quicker.

The LS3's cylinder heads feature rectangular intake ports that support exceptional airflow. They support great airflow at higher rpm for a broader horsepower band, along with strong, low-rpm torque. The intake ports that feed the combustion chambers, as well as the D-shaped exhaust ports, are designed for excellent high-rpm airflow.

The LS3's intake manifold ports are designed to match cylinder head. The composite manifold is manufactured with a lost core process to improve runner-to-runner variation and to reduce flow losses. Acoustic foam is sandwiched between the outside top of the intake manifold and an additional "skull cap" acoustic shell to reduce radiated engine noise.

Corvette models equipped with a manual transmission feature a dry sump oiling system which promotes exceptional lubrication system performance during extended high-rpm use under high cornering loads.

With ETC, there is no mechanical link between the accelerator pedal and the throttle body. A sensor at the pedal measures pedal angle and sends a signal to the engine control module (ECM), which in turn directs an electric motor to open the throttle at the appropriate rate and angle. The ETC system can deliver outstanding throttle response and greater reliability than a mechanical connection.

The LS3 has an advanced 58X crankshaft position encoder to ensure that ignition timing is accurate throughout its operating range. The new 58X crankshaft ring and sensor provide more immediate, accurate information on the crankshaft's position during rotation. This allows the engine control module to adjust ignition timing with greater precision, which optimizes performance and economy. Engine starting is also more consistent in all operating conditions.

The LS7's Gen-IV cylinder block shares two key design elements with GM's original small-block V-8: a 90-degree cylinder angle and 4.400-inch bore centers. The LS7 uses unique pressed-in cast iron cylinder liners to accommodate the largest cylinders bores in the engine family. The LS7 block also features very durable, doweled-in, forged-steel main bearing caps, which hold the balanced, forged-steel crankshaft in place and reduce crank flex.

The Gen IV block was developed with math-based tools and data acquired in GM's racing programs, and provides a light, rigid foundation for an impressively smooth engine. Its deep-skirt design helps maximize strength and minimize vibration. The bulkheads accommodate six-bolt, cross-bolted main-bearing caps that limit crank flex and stiffen the engine's structure. A structural oil pan further stiffens the powertrain.

A precision machining process typically reserved for high-performance engines, is used on the LS7 cylinder block to maximize engine life, reduce friction between engine parts and increase horsepower. It is advantageous in applications where cylinder head pressures are greater than average – such as with a supercharged engine – to ensure cylinder sealing and prevent scuffing of the piston against the bore wall. In the LS7 engine, this means improved bore life and ring sealing. True bores and better sealing are keys to optimizing power.

Lightweight titanium connecting rods are used in the LS7 to reduce the pressure on the rod end bearings and the main bearings, and allow the bearings to be optimally sized for the least amount of friction. The lightweight rods are matched with pistons that feature tapered wrist pins to reduce weight. The piston rings are anodized to reduce blow-by and friction, while the skirts are coated with a polymer material to limit bore scuffing and reduce noise.

The LS7's large displacement would mean little in terms of horsepower if the engine could not draw in and then expel enough air to take advantage. To that end the LS7 is fitted with high-flow cylinder heads that are derived from racing heads first proven on the track with the Corvette Racing team. The heads feature fully CNC-machined intake, exhaust ports and 70cc combustion chambers to reduce airflow restrictions, while the high machining consistency of the machining procedure enable's the LS7's high, 11.0:1 compression ratio.

The LS7's intake manifold ports are designed to match cylinder head. The composite manifold is manufactured with a lost core process to improve runner-to-runner variation and to reduce flow losses. Acoustic foam is sandwiched between the outside top of the intake manifold and an additional "skull cap" acoustic shell to reduce radiated engine noise.

Corvette models equipped with a manual transmission feature a dry sump oiling system which promotes exceptional lubrication system performance during extended high-rpm use under high cornering loads.

With ETC, there is no mechanical link between the accelerator pedal and the throttle body. A sensor at the pedal measures pedal angle and sends a signal to the engine control module (ECM), which in turn directs an electric motor to open the throttle at the appropriate rate and angle. The ETC system can deliver outstanding throttle response and greater reliability than a mechanical connection.

The LS7 has an advanced 58X crankshaft position encoder to ensure that ignition timing is accurate throughout its operating range. The new 58X crankshaft ring and sensor provide more immediate, accurate information on the crankshaft's position during rotation. This allows the engine control module to adjust ignition timing with greater precision, which optimizes performance and economy. Engine starting is also more consistent in all operating conditions.

The exhaust manifolds are made of hydroformed stainless steel, which is lighter than cast iron, and feature a unique four-into-one collector that designed to maximize airflow. Exhaust pipes on the LS7-equipped Corvette Z06 are three-inches in diameter, compared to the 2.5-inch pipes on Corvettes built with the 6.0L LS2.

The 6.2L engine block used with the LS9 is cast from 319-T7 aluminum and fitted with cast-iron cylinder liners. It has been strengthened 20 percent compared to prior generations of this engine, by optimizing the size of the bulkhead "windows" to take advantage of material thickness in the bulkhead. The enlarged bulkhead windows also improve bay-to-bay breathing by managing airflow inside the engine more efficiently, thereby decreasing pumping loss, or reducing resistance to the pistons' downward movement.

The engine block was developed with the latest math-based tools and data acquired in GM's racing programs, and it provides an exceptionally light, rigid foundation for an impressively smooth cam-in-block engine. Its deep-skirt design helps maximize strength and minimize vibration, and its aluminum construction reduces weight approximately 100 pounds compared to a conventional cast-iron cylinder block.

A precision machining process typically reserved for high-performance engines, is used on the LS9 cylinder block to maximize engine life, reduce friction between engine parts and increase horsepower. It is advantageous in applications where cylinder head pressures are greater than average – such as with a supercharged engine – to ensure cylinder sealing and prevent scuffing of the piston against the bore wall. In the LS9 engine, this means improved bore life and ring sealing. True bores and better sealing are keys to optimizing power.

The LS9's pistons are premium forged aluminum components, for a high-performance combination of low mass, high strength and durability. These are considerably lighter than conventional aluminum pistons, which translates to less reciprocating mass inside the engine. The LS9 also incorporates oil-spray piston cooling. Eight oil-squirting jets in the engine block drench the underside of each piston and the surrounding cylinder wall with an extra layer of cooling, friction-reducing oil. The oil spray reduces piston temperature, promoting extreme output and long-term durability.

Within the LS9's cylinder block spins a balanced, dropped-forged micro-alloy steel crankshaft with a nine-bolt flange to mount the flywheel. Titanium connecting rods mate the crank with the pistons, for the ultimate combination of strength and light weight. The titanium rods weigh roughly 25 percent less than conventional iron or steel. They reduce pressure on both the rod-end bearings and main bearings, and allow the bearings to be optimally sized for the least amount of friction.

A refined camshaft helps balance the 6.2L LS9's remarkable output with silky, tractable low-rev operation. It camshaft operates the engine's valves and its design is crucial to both power and smoothness.

The LS9 cylinder heads are manufactured with a unique rotocast method, which rotates the head mold as the molten alloy cools and essentially eliminates porosity, or microscopic pockets of air trapped in the casting. Rotocasting delivers a stronger part that helps maintain performance and structural integrity over the life of the engine.

To ensure appropriate fueling in all conditions, the LS9 features a dual-pressure fuel system. It delivers about 36 psi (250 kPa) at idle and low speeds. Yet the electronic throttle management system can immediately increase fuel pressure to 87 psi (600 kPa) for sustained high-speed operation or wide-open throttle. The dual-pressure system reacts according to throttle application, and presents several advantages. It limits the energy used by the fuel pump at low speeds, for maximum efficiency, and it reduces operational noise.

The LS9 also employs a center-feed fuel rail that delivers gasoline to the center of the injector rail and each bank. This helps reduce fuel pressure variation among the injectors, as well as noise.

The LS9's coil-on-plug ignition features advanced coils that are smaller and lighter than those used on previous V-8s. An individual coil for each spark plug delivers maximum voltage and consistent spark density, with no variation between cylinders.

State-of-the-art supercharging technology is the foundation of the LS9's remarkable performance. The supercharger is an air pump driven by the engine's crankshaft. It forces more air into the engine's combustion chambers than the engine could otherwise draw on its own. The increased volume of oxygen allows the engine to efficiently process more fuel, and thus generate more power.

An advanced intercooling system increases the 6.2L LS9's performance and extends its supercharger's benefits. The engine's charge cooler is integrated in the supercharger case just above the rotors, with two air-to-liquid cooling "bricks" that substantially lower the temperature of air used in the combustion process. Intercoolers are familiar features on supercharged and turbocharged engines. Similar in concept to an engine's radiator, intercoolers cool the air pumped by the charging device into the cylinders. Cooler air is denser air, which means more oxygen in a given volume, resulting in optimal combustion and more power. Traditionally, intercoolers look like small radiators mounted somewhere outside the engine, with air fed into the engine through a plumbing network.

To ensure the 6.2L LS9 operates at peak, low-friction efficiency, and to promote durability during extended high-rpm use under high cornering loads, the engine is equipped with a racing-style dry sump-type lubrication system and dual-gerotor oil pump.

The 6.2L LS9 exhaust manifolds are constructed of stainless steel and designed on the principle that low restriction and less pumping loss equals more horsepower and torque. Each manifold consists of four tubes hydroformed from 309 stainless steel. The manifolds are fitted with a pair of close-coupled catalytic converters that heat quickly, achieving light-off temperature and closed-loop operations in seconds.

With ETC, there is no mechanical link between the accelerator pedal and the throttle body. A sensor at the pedal measures pedal angle and sends a signal to the engine control module (ECM), which in turn directs an electric motor to open the throttle at the appropriate rate and angle. The ETC system can deliver outstanding throttle response and greater reliability than a mechanical connection.

The LS9 has an advanced 58X crankshaft position encoder to ensure that ignition timing is accurate throughout its operating range. The new 58X crankshaft ring and sensor provide more immediate, accurate information on the crankshaft's position during rotation. This allows the engine control module to adjust ignition timing with greater precision, which optimizes performance and economy. Engine starting is also more consistent in all operating conditions.

The LS9 is manufactured at the Performance Build Center.

The 6.2L engine block used with the LSA is cast from 319-T7 aluminum and fitted with cast-iron cylinder liners. Compared to previous blocks, it has been strengthened 20 percent by optimizing the size of the bulkhead "windows" to take advantage of material thickness in the bulkhead. The enlarged bulkhead windows also improve bay-to-bay breathing by managing airflow inside the engine more efficiently, thereby decreasing pumping loss, or reducing resistance to the pistons' downward movement.

The engine block was developed with the latest math-based tools and data acquired in GM's racing programs, and it provides an exceptionally light, rigid foundation for an impressively smooth cam-in-block engine. Its deep-skirt design helps maximize strength and minimize vibration, and its aluminum construction reduces weight approximately 100 pounds compared to a conventional cast-iron cylinder block.

A precision machining process reserved for high-performance engines, is used on the LSA cylinder block to maximize engine life, reduce friction between engine parts and increase horsepower. It is advantageous in applications where cylinder head pressures are greater than average – such as with a supercharged engine – to ensure cylinder sealing and prevent scuffing of the piston against the bore wall. In the LSA engine, this means improved bore life and ring sealing. True bores and better sealing are keys to optimizing power.

The LSA's pistons are aluminum-cast from a high-silicon alloy developed for its combination of strength and heat-management properties. Casting reduces noise-generating potential, compared to other high-performance piston materials, such as forged aluminum, and is specified when noise and vibration control is a priority. The hypereutectic pistons are also lighter than conventional steel, which translates to less reciprocating mass inside the engine. Less mass means greater efficiency, high-rpm capability and a feeling of immediate response as the engine builds rpm.

Within the LSA's cylinder block spins a balanced, dropped-forged steel crankshaft with an eight-bolt flange to mount the flywheel. The eight-bolt pattern increases clamping strength compared to naturally aspirated 6.2L V-8s, which use a six-bolt crank flange. Forged powder-metal connecting rods link the crankshaft and pistons. They are forged under extreme pressure from alloy metals reduced to powder, rather the melted to liquid, for a balance of low mass and high strength. They reduce pressure on both the rod-end bearings and main bearings, compared to conventional rods, and allow the bearings to be optimally sized for the least amount of friction.

A refined camshaft helps balance the 6.2L LSA's high output with smooth, tractable low-rpm performance. The torque-enhancing benefits of the supercharger allowed engineers to develop a "softer," lower-lift camshaft for the LSA, compared to the typical high-rev, high-power exotic car engine. The result is smoother operation at idle and during low-speed driving.

The LSA cylinder heads are manufactured with a unique rotocast method, which rotates the head mold as the molten alloy cools and essentially eliminates porosity, or microscopic pockets of air trapped in the casting. Rotocasting delivers a stronger part that helps maintain performance and structural integrity over the life of the engine.

To ensure appropriate fueling in all conditions, the LSA features a dual-pressure fuel system. It delivers about 36 psi (250 kPa) at idle and low speeds. Yet the electronic throttle management system can immediately increase fuel pressure to 87 psi (600 kPa) for sustained high-speed operation or wide-open throttle. The dual-pressure system reacts according to throttle application, and presents several advantages. It limits the energy used by the fuel pump at low speeds, for maximum efficiency, and it reduces operational noise.

The LSA also employs a center-feed fuel rail that delivers gasoline to the center of the injector rail and each bank. This helps reduce fuel pressure variation among the injectors, as well as noise.

The LSA's coil-on-plug ignition features advanced coils that are smaller and lighter than those used on previous V-8s. An individual coil for each spark plug delivers maximum voltage and consistent spark density, with no variation between cylinders.

State-of-the-art supercharging technology is the foundation of the LSA's remarkable performance. The supercharger is an air pump driven by the engine's crankshaft. It forces more air into the engine's combustion chambers than the engine could otherwise draw on its own. The increased volume of oxygen allows the engine to efficiently process more fuel, and thus generate more power.

An advanced intercooling system increases the 6.2L LSA's performance and extends its supercharger's benefits. The engine's charge cooler is integrated in the supercharger case just above the rotors, with two air-to-liquid cooling "bricks" that substantially lower the temperature of air used in the combustion process. Intercoolers are familiar features on supercharged and turbocharged engines. Similar in concept to an engine's radiator, intercoolers cool the air pumped by the charging device into the cylinders. Cooler air is denser air, which means more oxygen in a given volume, resulting in optimal combustion and more power. Traditionally, intercoolers look like small radiators mounted somewhere outside the engine, with air fed into the engine through a plumbing network.

To ensure peak, low-friction efficiency, and to promote durability during extended high-rpm operation, the LSA has a more powerful oil pump than the naturally aspirated 6.2L LS3. The oil pump capacity is increased to 33.8 gallons per minute and the LSA's six-quart oil pan is fitted with a liquid-to-air oil cooler.

The 6.2L LSA exhaust manifolds are fabricated from a premium high-silicon, high-moly iron alloy. The material delivers excellent heat management properties, and the design ensures the high flow volume required of an engine with the LSA's capability. Immediately downstream, the exhaust manifolds are fitted with a pair of close-coupled catalytic converters that heat quickly, achieving light-off temperature and closed-loop operations in seconds.

The LSA has an advanced 58X crankshaft position encoder to ensure that ignition timing is accurate throughout its operating range. The new 58X crankshaft ring and sensor provide more immediate, accurate information on the crankshaft's position during rotation. This allows the engine control module to adjust ignition timing with greater precision, which optimizes performance and economy. Engine starting is also more consistent in all operating conditions.

The Vortec 4.3L features an iron cylinder block based on the small-block V-8 architecture. Inside the block, the rotating assembly consists of a strong iron crankshaft, lightweight aluminum pistons and cracked powder-metal connecting rods.

A trio of ignition coils is mounted above the former location of the conventional distributor (a unique "stub" shaft is used to drive the oil pump). Each coil is directed by the engine's controller to fire two cylinders. The ignition system uses a 58X crankshaft-sensing reluctor wheel, similar to those used in GM's Gen IV V-8 engines.

The Vortec 4.3L incorporates a number of features designed to optimize performance and durability, while helping keep down ownership costs. They include:

• Machined water pump and specific gasket delivers better pump-to-block sealing
• Cast rocker arms offer more precise tolerances
• Low-permeable intake sealing system helps ensure minimal fuel emissions seeping out of the intake system
• Three layers of insulated tubing for the exhaust manifolds helps reduce noise
• Extended-life spark plugs are designed to go 100,000 miles (160,000 km) without the need for replacement
• Extended-life Dex-Cool coolant maintains its cooling and corrosion-inhibiting properties for 150,000 miles (240,000 km)

The Ecotec 1.4L turbo's cylinder block is made of strong gray cast iron, with five reinforced main bearings. The block offers excellent thermal properties that suit the cylinder pressure and loads generated by a turbocharger system. To minimize weight, it features hollow-frame construction, making it about 20 percent lighter than a conventional casting.

With a reinforced, solid-cast crankshaft, the Ecotec 1.4L offers strength and stiffness, particularly at higher rpm, to support the boosted cylinder pressure of the turbo system. The connecting rods are forged steel and the lightweight, hypereutectic pistons are designed with a thicker crown area and a unique ring pack to withstand the boost pressure and heat generated by the turbo system.

The Ecotec 1.4L turbo uses a unique variable-flow oiling system that helps maximize fuel efficiency. Rather than the linear operation of a conventional fixed-flow pump, it is accomplished with a crankshaft-driven oil pump that matches the oil supply to the engine load. The Ecotec 1.4L turbo's variable-flow pump changes its capacity based on the engine's demand for oil. This prevents using energy to pump oil that is not required for proper engine operation.

An aluminum oil pan is designed as a key structural component of the engine, adding stiffness that helps improve vibration characteristics.

An aluminum cylinder head with dual-overhead camshafts and four valves per cylinder is used on the Ecotec 1.4L turbo. The head's intake port design optimizes performance, efficiency and emissions by promoting greater charge motion of the intake air and a more complete burn of the air/fuel mixture. Sodium-filled exhaust valves are designed for the higher combustion temperatures of the turbo system.

The dual-overhead camshaft arrangement of the engine employs dual, continuously variable cam phasing to adjust the engine valves' opening and closing timing for optimal performance, fuel efficiency and emissions across the rpm.

The Ecotec 1.4L turbo uses a unique, integrated turbocharger and exhaust manifold. The turbocharger size was chosen with an emphasis on low speed torque and throttle response. It requires fewer parts, is lighter than a conventional system, helps lower engine compartment temperatures and helps the engine warm up faster. The turbocharger is lubricated by engine oil and is liquid cooled for long-term reliability.

The coolant thermostat's operating point is electronically controlled to optimize engine temperatures during different phases of operation to enhance fuel efficiency. The engine control module monitors sensors and controls the thermostat based on mapping that takes into account the wide range of engine operating conditions, including temperature and load.

The eAssist system uses power stored in an advanced, 115V lithium-ion battery and channels it to a 15-kW motor generator to provide an electrical boost in various driving scenarios, optimizing engine and transmission operation and increasing fuel economy through:

• Regenerative braking, which provides up to 15 kW of electricity to charge the battery
• Providing up to 11 kW (15 hp) of electric power assistance during acceleration
• Automatic engine shut-off when the vehicle is stopped
• Aggressive fuel cut-off during deceleration down to zero vehicle speed, enabled by the torque smoothing provided by the motor-generator unit
• Intelligent charge/discharge of the high-voltage battery.

The Ecotec 2.4L's sand-cast cylinder provides excellent structural support, as well as enabling greater control of noise, vibration and harshness. The main bearing bulkheads, which support the crank bearing, as well as the cylinder bore walls, have been significantly strengthened to support increased engine loads.

The Ecotec 2.4L's pistons use lightweight aluminum pistons, for less reciprocating mass inside the engine that enhances efficiency, decreases vibration and bolsters the feeling of performance as rpm increases. Each piston has its own directed jet that sprays oil toward its skirt, coating its underside and the cylinder wall with an additional layer of lubricant. The extra lubrication cools the pistons, reducing friction and operational noise, while also bolstering the engine's durability.

The Ecotec 2.4L has a SPM 319 aluminum cylinder head that is cast with advanced semi-permanent mold technology. This provides excellent strength, reduced machining and optimal port flow. The cylinder head is designed specifically for direct injection into each combustion chamber and includes premium valve seat, valve guide and valve materials. The cylinder head also has integral cast oil passages that feed a set of internal oil control valves that activate cam phasers, enabling variable valve timing.

Overhead cams are the most direct, efficient means of operating the valves, while four valves per cylinder increase airflow in and out of the engine. This arrangement is integrated on the Ecotec 2.4L's lightweight aluminum cylinder head. Both the intake and exhaust cams have hydraulically operated vane-type phasers that are managed by a solenoid and directed by the engine control module (ECM).

Direct injection moves the point where fuel feeds into an engine closer to the point where it ignites, enabling greater combustion efficiency. Direct injection also reduces emissions, particularly cold-start emissions, by about 25 percent.

With direct injection, the higher compression ratio is possible because of a cooling effect as the injected fuel vaporizes in the combustion chamber. This reduces the charge temperature and lessens the likelihood of spark knock. The direct injection fuel injectors have been developed to withstand the greater heat and pressure inside the combustion chamber and also feature multiple outlets for best injection control.

A high-pressure, cam-driven pump provides the fuel pressure required of the direct injection system in the Ecotec 2.4L. The engine-mounted fuel pump is augmented by a conventional electrically operated supply pump in the fuel tank.

The Ecotec 1.4L cylinder block is made of strong gray cast iron, with five reinforced main bearings. To minimize weight, it features hollow-frame construction, making it about 20 percent lighter than a conventional casting. The block also incorporates a gray cast iron bedplate that helps reduce engine vibration; and the cylinders within the block are triple-honed for a smoother finish that minimizes piston friction and overall wear, while also optimizing oil and fuel consumption.

An aluminum oil pan is designed as a key structural component of the engine, adding stiffness that helps improve vibration characteristics.

The Ecotec 1.4L uses a unique variable-flow oiling system that helps maximize fuel efficiency. Rather than the linear operation of a conventional fixed-flow pump, it is accomplished with a crankshaft-driven oil pump that matches the oil supply to the engine load. The Ecotec 1.4L's variable-flow pump changes its capacity based on the engine's demand for oil. This prevents using energy to pump oil that is not required for proper engine operation.

The dual-overhead camshaft arrangement of the engine employs dual, continuously variable cam phasing to adjust the engine valves' opening and closing timing for optimal performance, fuel efficiency and emissions across the rpm.

An aluminum cylinder head with dual-overhead camshafts and four valves per cylinder is used on the Ecotec 1.4L turbo. The head's intake port design optimizes performance, efficiency and emissions by promoting greater charge motion of the intake air and a more complete burn of the air/fuel mixture.

The pair of camshafts in the Ecotec 1.4L is hollow and lighter than conventional solid shafts. Along with helping reduce the overall weight of the engine, they lower the inertia of the valvetrain, allowing the engine to rev higher and more quickly. The camshafts are driven by durable chains.

A low-mass DOHC roller-finger camshaft follower is used to minimize friction and maintenance. It operates with very low frictional losses, helping enhance efficiency and lower emissions. The hydraulic lash adjusters and the chain cam drive require no maintenance during the life of the engine.

The coolant thermostat's operating point is electronically controlled to optimize engine temperatures during different phases of operation to enhance fuel efficiency. The engine control module monitors sensors and controls the thermostat based on mapping that takes into account the wide range of engine operating conditions, including temperature and load.

Volt's Ecotec 1.4L engine features a coil-on-plug ignition system and platinum-tipped spark plugs, which reduce maintenance and promote optimal performance and efficiency. With the coil-on-plug design, individual ignition coils are connected via a short lead wire to the spark plugs over each cylinder. This direct ignition system design eliminates the need to route spark plug wires in the engine compartment, while ensuring maximum spark energy for each plug.

The platinum-tipped plugs are designed to last for 100,000 miles without the need for replacement, reducing the need for and cost of maintenance.

The Ecotec 1.4L turbo's cylinder block is made of strong gray cast iron, with five reinforced main bearings. The block offers excellent thermal properties that suit the cylinder pressure and loads generated by a turbocharger system. To minimize weight, it features hollow-frame construction, making it about 20 percent lighter than a conventional casting.

With a reinforced, solid-cast crankshaft, the Ecotec 1.4L offers strength and stiffness, particularly at higher rpm, to support the boosted cylinder pressure of the turbo system. The connecting rods are forged steel and the lightweight, hypereutectic pistons are designed with a thicker crown area and a unique ring pack to withstand the boost pressure and heat generated by the turbo system.

The Ecotec 1.4L turbo uses a unique variable-flow oiling system that helps maximize fuel efficiency. Rather than the linear operation of a conventional fixed-flow pump, it is accomplished with a crankshaft-driven oil pump that matches the oil supply to the engine load. The Ecotec 1.4L turbo's variable-flow pump changes its capacity based on the engine's demand for oil. This prevents using energy to pump oil that is not required for proper engine operation.

An aluminum oil pan is designed as a key structural component of the engine, adding stiffness that helps improve vibration characteristics.

An aluminum cylinder head with dual-overhead camshafts and four valves per cylinder is used on the Ecotec 1.4L turbo. The head's intake port design optimizes performance, efficiency and emissions by promoting greater charge motion of the intake air and a more complete burn of the air/fuel mixture. Sodium-filled exhaust valves are designed for the higher combustion temperatures of the turbo system.

The dual-overhead camshaft arrangement of the engine employs dual, continuously variable cam phasing to adjust the engine valves' opening and closing timing for optimal performance, fuel efficiency and emissions across the rpm.

The Ecotec 1.4L turbo uses a unique, integrated turbocharger and exhaust manifold. The turbocharger size was chosen with an emphasis on low speed torque and throttle response. It requires fewer parts, is lighter than a conventional system, helps lower engine compartment temperatures and helps the engine warm up faster. The turbocharger is lubricated by engine oil and is liquid cooled for long-term reliability.

The coolant thermostat's operating point is electronically controlled to optimize engine temperatures during different phases of operation to enhance fuel efficiency. The engine control module monitors sensors and controls the thermostat based on mapping that takes into account the wide range of engine operating conditions, including temperature and load.