VORTEC L I-5 (L52) 2006 model year summary. Full descriptions of new or changed features

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1 VORTEC L I-5 (L52) 2006 model year summary Application in 2006 Hummer H3 Improved cam phaser Returnless fuel injection Full descriptions of new or changed features Application in HUMMER H3 The Vortec L inline five-cylinder (RPO L52) will power the 2006 HUMMER H3 sportutility. Vortec 3500s built for this application are identical to those powering the Chevrolet Colorado and GMC Canyon midsize pickups. As an extension of the HUMMER brand, the HUMMER H3 provides ultimate off-road performance capabilities in a smaller, more maneuverable and affordable size. The Vortec 3500 provides the power needed for off-road driving, combined with excellent fuel economy for this type of vehicle. Improved camp phaser The Vortec 3500 is now equipped with a vane-type cam phaser, replacing the helical spline and piston phaser used since the engine s launch. The vane phaser represents the current state of the art in cam phasers, providing such benefits as quicker, more efficient response and increased robustness/ durability. The Vortec 3500 was one of the world s first truck engines with variable valve timing or cam phasing. The cam phaser changes exhaust cam lobe timing relative to the cam-drive sprocket, which in turn varies exhaust valve timing on the fly, maximizing engine performance for given demands and conditions. At idle, for example, the exhaust cam is at the full advanced position for minimum intake-valve overlap. That allows exceptionally smooth idling. Under other operating demands, the phaser adjusts to deliver optimal exhaust-valve timing for performance, drivability and fuel economy. The result is 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 drivability. Because it manages valve overlap at optimum levels, cam phasing also eliminates the need for an Exhaust Gas Recirculation (EGR) system.

2 As was the spline-piston phaser, the new vane phaser is actuated by hydraulic pressure from engine oil, and managed by a solenoid that is set to a specified duty-cycle and controls oil pressure on the phaser. Yet the operating mechanism is different. Instead of a helical spline and piston, the vane phaser uses a wheel with four vanes (like a propeller) to turn the camshaft relative to the cam-sprocket. The solenoid directs oil to pressure points on either side of the four vanes; the vanes, and camshaft, turn in the direction of the oil flow. The more pressure, the more the phaser and camshaft turn. Like the previous phaser, the vane phaser turns the Vortec 3500 s camshaft a maximum 24 degrees relative to the sprocket. The vane phaser is a much simpler device than the spline-piston phaser, with fewer parts. The vane wheel is made of extruded aluminum; it requires less machining and it s less expensive to manufacture. Moreover, the vane phaser is more robust. It s validated to 10 years or 150,000 miles of operation. It is less sensitive to disruption from excessive debris in the oil. Most important, the vane phaser performs more quickly and efficiently than the spline-piston phaser. Because it generates less friction, in turns the camshaft faster in some conditions, as when the engine is warm and operating at low rpm, nearly four times faster. This improved response time will be transparent to the driver, but it improves the Vortec 3500 s overall efficiency and reduces compromises when balancing performance, driveability, fuel efficiency and emissions reduction. More precise control gives Powertrain engineers more options in calibrating the cam phaser to maximize its benefits. Returnless fuel injection All Vortec 3500s are equipped with a new "returnless" fuel injection system that eliminates fuel return lines between the engine and the gasoline tank. The new fuel system is also known as a demand system. Before model year 2006, the Vortec 3500 s Sequential Fuel Injection (SFI) used a return line to manage fuel pressure by bleeding off excess fuel at the fuel rail and returning the excess to the fuel tank. The new system eliminates the return lines and moves the fuel-pressure regulator from the fuel rail on the engine to the fuel tank. But because the returnless system delivers only the amount of fuel needed by the injectors, and returns no fuel to the fuel tank, it eliminates heat

3 transfer from the engine to the fuel tank. This reduces the amount of vapor generated in the tank and captured by the evaporative emissions control system. Returnless fuel injection allows the Vortec 3500 to meet near-zero evaporative emissions standards mandated by the Environmental Protection Agency and California Air Resources Board for implementation in Overview The Vortec L inline five-cylinder was introduced for model year 2004 as the optional engine in the all-new Chevrolet Colorado and GMC Canyon pickups. It was developed jointly with the award-winning Vortec 4200 I-6 (RPO LL8) and the Vortec 2800 I-4 (RPO LK5), based on the philosophy that a true family of truck engines provides the best value and performance for the customer, and the best return on investment for General Motors. The Vortec 3500 brings premium features and advanced technologies technologies previously reserved largely for premium passenger car engines to the new HUMMER H3 and midsize pickups. These include aluminum-intensive construction, and an engine block and cylinder head cast with GM s patented lost-foam process; dual overhead cams with exhaust cam phasing, coil-on-plug ignition and electronic throttle control for maximum efficiency and performance; a main-bearing structural ladder; die-cast aluminum oil pan; and direct mount accessories for luxury-grade noise, vibration and harshness control. This inline five-cylinder introduced a number of firsts to GM Powertrain s line of truck engines. With the Vortec 2800, the Vortec 3500 was the first truck application (and one of the first North American applications) of a one-piece exhaust manifold-catalytic converter. Emissions engineers know that the faster a catalytic converter reaches full operating temperature, the better the converter reduces pollutants in automotive exhaust. This led to the concept of the close-coupled catalyst. Because the exhaust ports and exhaust manifold heat more rapidly than any part of an engine, moving the catalytic converter closer to the manifold allows the catalyst to heat more quickly. So positioned, the catalytic converter achieves light-off the temperature at which exhaust emissions are most efficiently oxidized more quickly. The Vortec 3500 s cast-nodular iron exhaust manifold and initial catalytic converter are welded together and installed as one part, taking the close-coupled concept to its practical limit. The

4 engine also has a second, underfloor catalyst downstream from the first. So the Vortec 3500 meets emissions requirements without expensive, add-on emissions control devices, such as a separate Exhaust Gas Recirculation (EGR) system or Air Injection Reaction (AIR), which add cost, assembly complexity and weight. The Vortec inline engines have a high compression ratio but still use regular-grade gasoline. Typically, high compression engines require high-octane gas to produce maximum power, or to avoid the potentially damaging effects of spark knock or detonation. The Vortec 3500 s 10:1 compression ratio delivers the horsepower and combustion efficiency advantages of higher compression, yet allows this inline five-cylinder to operate at peak output on regular gas. These seemingly incompatible objectives were achieved by optimizing combustion chamber design and airflow to the engine and by applying advanced engine management technologies. The Vortec 3500 was developed with balance shafts. Balance shafts are carefully crafted counterweights that offset the inherent imbalance forces of the engine. They are key contributors to the Vortec 3500 s outstanding noise, vibration and harshness characteristics. The shafts rotate in opposite directions at twice engine speed to cancel vibrations that might otherwise be transmitted through the engine mounts to the steering wheel and vehicle seats. They also reduce interior noise. On the Vortec inline engines, the balance shafts are operated from the rear of the crankshaft to take advantage of efficiencies in the family-of-engines philosophy. This allows a common design for the front crank hub and cam drive on all three engines. To further maximize efficiencies, the chain-drive mechanism that spins the balance shafts the chain, sprockets and tensioner is identical in the Vortec 3500 and 2800, and it has been designed to minimize friction and parasitic power loss in both engines. The only difference is the crucial one: the shape and weighting of the balance shafts themselves. Because of its cylinder configuration, an inline five-cylinder engine creates it own unique forces on the crankshaft. Given these characteristics, the Vortec 3500 balance shafts each have a pair of counterweights. The two balance shafts act together to create forces equal and opposite to the inherent engine forces, thereby canceling out these vibrations. The same attention to detail applied throughout the Vortec 3500, including things as simple and important as oil filter and spark plugs. Located toward the front of the engine on the right side, the oil filter is easily accessible from underneath. In addition, the filter is mounted pointing

5 straight down, reducing the likelihood of spillage when the filter is unthreaded and lowered during removal. The spark plugs, located in the center of the cam cover, are just as easy to remove. One fastener holds the ignition-coil cassette. When the cassette is removed, the plugs can be easily accessed. With the Vortec 3500 s GM Oil Life Monitoring System, an owner should never pay for an unnecessary oil change again, nor worry that the engine oil has degraded to the point where it has lost its lubricating properties. That, in turn, can significantly reduce the amount of motor oil used, and the amount of used motor oil the must be recycled. The industry-leading GM Oil Life Monitoring System calculates oil life based on a number of variables, including engine speed, operating temperature, load or rpm variance and period of operation at any given load and temperature. It then recommends a change when it s actually needed, rather than by some predetermined mileage interval. In extreme operating conditions, such as short periods of operation in very cold temperatures, the GM Oil Life System might recommend a change in as few as 3,000-3,500 miles. When the engine runs at moderate loads for extended periods with little variance, the system might not recommend an oil change for 15,000 miles. The Vortec 3500 also introduced firsts in manufacturing efficiency. Its assembly plant at GM Powertrain s Tonawanda, N.Y. engine complex melds the best manufacturing processes from Powertrain plants around the world, and is a model of efficiency. The Vortec 3500 is built alongside the Vortec 2800 I-4, and both can be built on the same assembly lines with 100- percent flexibility to build either product. Moreover, the Vortec 3500 and 2800 represent GM s first North American application of a true powertrain module or sub-assembly, introducing a new level of both quality and assembly efficiency to both powertrain and vehicle assembly plants. From the engine plant in Tonawanda, the Vortec 3500 is shipped to a module plant near the HUMMER H3 and Colorado/Canyon assembly plant in Shreveport, La. There the engine is mated with the transmission, all accessories such as AC compressor and power steering pump, and transfer cases for fourwheel drive models. The powertrain module is then sent to the vehicle plant and installed in the trucks as a single assembly. Powertrain s inline family philosophy first bore fruit with the award-winning Vortec 4200 I-6 (RPO LL8), launched in the 2002 midsize SUVs, including the Chevrolet TrailBlazer and GMC Envoy.

6 The Vortec 4200 delivers more peak horsepower, comparable torque and better mileage than competitors V-8s. The inline engine provides performance and cost advantages. With a single-bank block and one cylinder head, development cost is reduced significantly compared to a V-configuration. The inline design delivers manufacturing advantages as well. Fewer parts mean faster assembly, with less post-assembly adjustment and lower cost of ownership. Moreover, the Vortec inline design provides the basis for a complete range of engines with very different character, building the foundation for the Vortec 3500 and Vortec While components such as the crankshaft and large castings are different, nearly 80 percent of the Vortec 3500 s parts are shared with the Vortec 4200, by part number. The Vortec 3500 shares nearly 90 percent of its parts with the Vortec That means a line of distinct engines that require what amounts to finish work, rather than ground-up development. The philosophy is simple and effective: Use common components when it is transparent and most efficient, and develop distinct components when class-leading performance or customers demand it. In vehicle assembly plants, the inline engines allow maximum commonization. Compared to assembly of the 2003 Chevrolet S10 and GMC Sonoma, with their inline four-cylinder and V-6 engine choices, the Shreveport plant has nearly 500 fewer distinct interfaces with the Vortec 3500 and That means the same attachment points, considerably more common connections, fewer tool changes and few line slow-downs. The result is shorter vehicle assembly time and improved build quality, and the results ultimately reach the customer. The premium features, manufacturing efficiencies and design advantages of a true family of engines mean little if the finished product doesn t deliver what customers demand. The Vortec 3500 delivers with the best balance of performance, fuel economy, low emissions and noise, vibration and harshness control in the marketplace, and with exclusive durability enhancing features and very low maintenance. Bottom line: The Vortec 3500 delivers the power of V-6 with the efficiency of an I-4. It produces more horsepower than many V-6 engines in competing midsize truck models, while at the same time providing outstanding fuel economy.

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