CXLTsouth
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2012 ECOTEC 2.0L I-4 VVT DI TURBO (LHU)
Vehicle Applications
Buick Regal / Regal GS
Product Highlights
· Twin-scroll turbocharger
· Air-to-air intercooler
· Gen II sand-cast engine block
· Forged steel crankshaft
· Aluminum pistons with jet-spray cooling
· Rotocast aluminum cylinder head with sodium-filled exhaust valves
· DOHC with continuously variable valve timing
· Direct injection
· Cam-driven high-pressure fuel pump
· E85 flex-fuel capable (LHU only)
· Cam-driven vacuum pump (LHU only)
Overview
[FONT=BNEFJI+Arial]Available in the Buick Regal CXL, the Ecotec 2.0L turbo (LHU) is a next-generation[/FONT] derivative of the advanced Ecotec 2.0L turbo LNF engine, which introduced for the 2007 model year and was the first North American engine with direct injection. It is tuned to meet the unique performance, efficiency and quietness targets of the Buick Regal and Regal GS.
The Regal is a global car and the Ecotec 2.0L turbo's development applied the best practices of technical centers in Europe and North America. It was subjected to one of the toughest, most comprehensive validation processes ever at GM, which included millions of miles of real-world road testing in a broad range of climates and environments. The result is a powerful and efficient engine that delivers the smoothness and quietness commensurate with Buick.
As with all Ecotec engines, it features durability and technology features familiar in premium V-type engines, including low-friction hydraulic roller-finger valve operation and an electronic throttle. A hydraulic tensioner keeps the timing chain adjusted for life, and extended-life spark plugs deliver 100,000 miles (160,000 km) of service.
Additional Ecotec family traits include:
· Dual overhead camshafts (DOHC) with four valves per cylinder
· Twin counter-rotating balance shafts to cancel the second-order vibration typical in four-cylinder inline engines
· Full-circle transmission attachment and a structural oil pan that bolts to both the engine block and transmission bell housing.
Gen II Engine Block
The Ecotec 2.0L turbo sand-cast cylinder block is a superior refinement of previous Ecotec engine block castings. [FONT=LOPBJO+Arial]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.[/FONT]
The main bearing bulkheads, which support the crank bearings, as well as the cylinder bore walls have been significantly strengthened to support increased engine loads. Refinements to the oil distribution system enable improved oil flow throughout the engine and an expansion of the coolant jacket, along with the use of cast-in-place bore liners, allows more precise bore roundness and improves the block’s ability to dissipate heat.
Rotating Assembly
The crankshaft is made of drop forged steel with induction heat-treated fillets and cross-drilled chamfered oil passages for racing-grade lubrication characteristics. Forged powdered metal connecting rods incorporate a larger, forged I-beam cross section for added strength in this turbocharged application.
The pistons in the 2.0L turbo are lightweight cast aluminum, which reduces reciprocating mass inside the engine. This enhances efficiency and the feeling of performance as the rpm increases. The tops of the pistons have a dish shape that deflects injected fuel toward the spark plugs, optimizing the thorough-combustion benefits of direct injection.
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, reduces both friction and operational noise and bolsters the engine's durability.
Rotocast Aluminum Cylinder Head with Sodium Filled Exhaust Valves
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. In other Ecotec engines, the fuel injectors are mounted in the intake ports but the 2.0L turbo head has unique injector mounting locations below the ports. Apart from injector installation, the head has conventional port and combustion chamber designs, both are optimized for direct injection and high boost pressure.
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. At normal engine operating temperatures, the sodium inside the valve stem fuses and becomes liquid. The liquid sodium improves conductivity, promoting heat transfer away from the valve face and valve guide to the cooler end of the stem, where it more readily dissipates. This helps maintain a lower, more uniform valve temperature, reducing wear on the valve guide for better alignment and a consistent seal between the valve seat and valve face over the life of the engine.
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.
DOHC with Continuously 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 2.0L's lightweight aluminum cylinder head.
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. 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). The phasers turn the camshaft relative to the drive sprocket, allowing intake and exhaust valve timing to be adjusted independently.
Cam phasing changes the timing of valve operation as conditions such as rpm and engine load vary. It 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. Because it manages valve overlap at optimum levels, it eliminates the need for a separate exhaust gas recirculation (EGR) system. Variable valve timing can be even more valuable in turbocharged engine. The ECM can adjust valve overlap at low rpm to optimize turbo response, delivering a more immediate rush of acceleration-producing torque.
The Ecotec 2.0L turbo 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. The cam reluctors work in conjunction with a 58X crankshaft position encoder to ensure the precisely accurate spark timing required of a direct-injection engine. This dual timing system also provides a reliable backup in the event either a camshaft or crankshaft sensor fails.
Vehicle Applications
Buick Regal / Regal GS
Product Highlights
· Twin-scroll turbocharger
· Air-to-air intercooler
· Gen II sand-cast engine block
· Forged steel crankshaft
· Aluminum pistons with jet-spray cooling
· Rotocast aluminum cylinder head with sodium-filled exhaust valves
· DOHC with continuously variable valve timing
· Direct injection
· Cam-driven high-pressure fuel pump
· E85 flex-fuel capable (LHU only)
· Cam-driven vacuum pump (LHU only)
Overview
[FONT=BNEFJI+Arial]Available in the Buick Regal CXL, the Ecotec 2.0L turbo (LHU) is a next-generation[/FONT] derivative of the advanced Ecotec 2.0L turbo LNF engine, which introduced for the 2007 model year and was the first North American engine with direct injection. It is tuned to meet the unique performance, efficiency and quietness targets of the Buick Regal and Regal GS.
The Regal is a global car and the Ecotec 2.0L turbo's development applied the best practices of technical centers in Europe and North America. It was subjected to one of the toughest, most comprehensive validation processes ever at GM, which included millions of miles of real-world road testing in a broad range of climates and environments. The result is a powerful and efficient engine that delivers the smoothness and quietness commensurate with Buick.
As with all Ecotec engines, it features durability and technology features familiar in premium V-type engines, including low-friction hydraulic roller-finger valve operation and an electronic throttle. A hydraulic tensioner keeps the timing chain adjusted for life, and extended-life spark plugs deliver 100,000 miles (160,000 km) of service.
Additional Ecotec family traits include:
· Dual overhead camshafts (DOHC) with four valves per cylinder
· Twin counter-rotating balance shafts to cancel the second-order vibration typical in four-cylinder inline engines
· Full-circle transmission attachment and a structural oil pan that bolts to both the engine block and transmission bell housing.
Gen II Engine Block
The Ecotec 2.0L turbo sand-cast cylinder block is a superior refinement of previous Ecotec engine block castings. [FONT=LOPBJO+Arial]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.[/FONT]
The main bearing bulkheads, which support the crank bearings, as well as the cylinder bore walls have been significantly strengthened to support increased engine loads. Refinements to the oil distribution system enable improved oil flow throughout the engine and an expansion of the coolant jacket, along with the use of cast-in-place bore liners, allows more precise bore roundness and improves the block’s ability to dissipate heat.
Rotating Assembly
The crankshaft is made of drop forged steel with induction heat-treated fillets and cross-drilled chamfered oil passages for racing-grade lubrication characteristics. Forged powdered metal connecting rods incorporate a larger, forged I-beam cross section for added strength in this turbocharged application.
The pistons in the 2.0L turbo are lightweight cast aluminum, which reduces reciprocating mass inside the engine. This enhances efficiency and the feeling of performance as the rpm increases. The tops of the pistons have a dish shape that deflects injected fuel toward the spark plugs, optimizing the thorough-combustion benefits of direct injection.
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, reduces both friction and operational noise and bolsters the engine's durability.
Rotocast Aluminum Cylinder Head with Sodium Filled Exhaust Valves
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. In other Ecotec engines, the fuel injectors are mounted in the intake ports but the 2.0L turbo head has unique injector mounting locations below the ports. Apart from injector installation, the head has conventional port and combustion chamber designs, both are optimized for direct injection and high boost pressure.
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. At normal engine operating temperatures, the sodium inside the valve stem fuses and becomes liquid. The liquid sodium improves conductivity, promoting heat transfer away from the valve face and valve guide to the cooler end of the stem, where it more readily dissipates. This helps maintain a lower, more uniform valve temperature, reducing wear on the valve guide for better alignment and a consistent seal between the valve seat and valve face over the life of the engine.
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.
DOHC with Continuously 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 2.0L's lightweight aluminum cylinder head.
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. 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). The phasers turn the camshaft relative to the drive sprocket, allowing intake and exhaust valve timing to be adjusted independently.
Cam phasing changes the timing of valve operation as conditions such as rpm and engine load vary. It 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. Because it manages valve overlap at optimum levels, it eliminates the need for a separate exhaust gas recirculation (EGR) system. Variable valve timing can be even more valuable in turbocharged engine. The ECM can adjust valve overlap at low rpm to optimize turbo response, delivering a more immediate rush of acceleration-producing torque.
The Ecotec 2.0L turbo 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. The cam reluctors work in conjunction with a 58X crankshaft position encoder to ensure the precisely accurate spark timing required of a direct-injection engine. This dual timing system also provides a reliable backup in the event either a camshaft or crankshaft sensor fails.
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