modifiche 2007 agli ecotec II e v6 H.F

[simonepietro]

Nonostante che il Gruppo GM sia in difficolta economiche continua periodicamente a attingere al bagaglio tecnico del progetto ECOTEC II e GM H. F , anche affinandoli nel tempo.

2007 Ecotec 2.2L I4 ( L61 )

ECOTEC 2.2L I4 (L61) CAR AND TRUCK ENGINE

2007 Model Year Summary

Gen II Engine Block

Cylinder Head Improvements

New Camshaft Design

E37 Engine Control Module

58X Crankshaft Reluctor Ring

Digital Crank and Cam Sensors

Individual Coil-on-Plug Ignition

Vented Starter Solenoid

New MAP Sensor

New Intake Manifold Seals

New Oil Filter Element

Improved Emissions Performance

Full Description of New and Updated Features

Gen II Engine Block

The Ecotec 2.2L starts with a refined engine block, introduced for 2006 with the Ecotec 2.4L VVT (RPO LE5). The Gen II block was developed with data acquired in racing programs and the latest math-based tools. Both the bore walls and bulkheads, or the structural elements that support the crank bearings, have been strengthened, with only a minimal weight increase (approximately 2.5 pounds). The coolant jackets have been expanded, allowing more precise bore roundness and improving the block’s ability to dissipate heat. Coolant capacity increases approximately .5 liter.

The cylinder block is the engine’s foundation, and crucial to its durability, output and smooth operation. For GM, the common Gen II Ecotec block increases assembly efficiency. For the customer, the result is more efficient cooling, more strength to accommodate additional power, as in the new Ecotec 2.0L direct-injection Turbo (RPO LNF) and better noise, vibration and harshness control.

Cylinder Head Improvements

The Ecotec 2.2L also benefits from cylinder head refinements introduced on the 2.4L VVT. The exhaust ports have been enlarged slightly with machining improvements to expel exhaust gas more efficiently. Both engines share a common nodular cast iron exhaust manifold, chosen for its durability and sound-deadening properties. The improvements to the cylinder head increase Ecotec 2.2L horsepower slightly in most applications (see specs).

New Camshaft Design

The exhaust cam has been re-profiled to take advantage of refinements in the cylinder head. Maximum exhaust valve lift does not change, but duration increases slightly. The cams also feature a new 4X timing reluctor, replacing timing sensors previously contained in the ignition-coil cassette (see Individual Coil-On-Plug ignition, below). The powder metal reluctor wheel is pressed onto the camshaft at the rear. The 4X reluctor improves ignition timing accuracy and maintains precise consistency over the life of the engine.

Individual Coil-On-Plug Ignition

The Ecotec 2.2.L is equipped with individual coil-on-plug ignition, or four separate coils. Each coil sits directly over a spark plug, with no wire in between. Previous Ecotec 2.2Ls had two coils in a single cassette, with each coil shared by two spark plugs. Individual coil-on-plug delivers maximum voltage and the most consistent spark density. The 2.2L’s cast aluminum cam cover has been redesigned to accommodate the four coils.

E37 Engine Control Module

An advanced controller manages the multitude of operations that occur within the Ecotec 2.2L every split second. The E37 is the S-3 Controller within GM’s new family of three engine control modules (ECM) that will direct nearly all the engines in Powertrain’s line-up. The E37 is the high-value variant, yet it’s anything but basic. It features 32-bit processing, compared to the conventional 16-bit processing in previous Ecotec 2.2Ls. It operates at 59 MHz, with 32 megabytes of flash memory, 128 kilobytes of RAM and a high-speed CAN bus, and it synchronizes several dozen functions, from spark timing to cruise control operation to traction control calculations. The E37 works roughly 50 times faster than the first computers used on internal combustion engines in the late 1970s, which managed five or six functions.

The family strategy behind GM’s new ECMs allows engineers to apply standard manufacturing, software and service procedures to all powertrains, and quickly upgrade certain engine technologies and calibration capabilities while leaving others alone. It creates both assembly and procurement efficiencies, as well as volume sourcing. In short, it creates a solid, flexible, efficient foundation, allowing engineers to focus on innovations and get them to market more quickly. The family of controllers means the ECM and corresponding connectors can be packaged and mounted identically in virtually every GM vehicle. Powertrain creates all the software for the three ECMs, which share a common language and hardware interface that’s tailored to each vehicle.

The E37 also applies a new, rate-based monitoring protocol sometimes known as run-at-rate diagnostics. Rate-based diagnostics improve the robustness of the Onboard Diagnostics System (OBD II) and ensure optimal performance of emissions control systems. The new software increases the frequency at which the ECM checks various Ecotec 2.2L systems, and particularly emissions-control systems such as the catalytic converter and oxygen sensors. Rate-based diagnostics more reliably monitor real-world operation of these systems, and allow regulatory agencies to more easily measure and certify emissions compliance.

58X Crankshaft Reluctor Ring

The Ecotec 2.2L has an advanced 58X crankshaft position encoder to ensure that ignition timing is accurate throughout its operating range. The 58X ignition system uses a unique crankshaft ring and sensor to provide the new E37 ECM more immediate information on the crankshaft’s position during rotation. This allows the controller to adjust ignition timing with greater precision, which optimizes performance and economy. Engine starting also is more consistent with reduced crank time. The powder metal 58X reluctor ring is bolted to a crankshaft counterweight.

Digital Crank and Cam Sensors

New digital sensors are common with the Ecotec 2.4L VVT and, with the 4X intake cam and 58X crank reluctors along with the new E37 ECM, they complete the ignition timing loop. This dual-position sensing system ensures extremely accurate timing for the life of the engine.

Vented Starter Solenoid

A new starter solenoid helps ensure starting performance in extreme cold temperatures. The solenoid case now has a micromesh-covered vent and an O-ring between the case and the starter motor. The mesh protects the solenoid from debris particles but prevents moisture buildup in the case. When the Ecotec 2.2L is warm, any moisture on the solenoid evaporates through the vent. The vented solenoid virtually eliminates the possibility of cold-start problems associated with solenoid icing.

New MAP Sensor

An advanced manifold absolute pressure (MAP) sensor completes upgrades to the Ecotec 2.2L’s control system. The MAP sensor is a variable resistor used to monitor the difference between atmospheric and manifold pressure, which tends to increase when the engine is operating under a higher load or at wide-open throttle. The ECM uses information from the MAP sensor to adjust spark timing and fuel delivery to optimize performance and minimize emissions. The new MAP sensor improves fidelity, or accuracy, and takes full advantage of the E37 ECM’s capabilities.

New Intake Manifold Seals

The Ecotec 2.2L is equipped with new intake manifold and throttle body sealing gaskets manufactured from a fluorocarbon material. The new gaskets are more resistant to most chemicals, for maximum durability, and particularly impermeable to hydrocarbon molecules. Gasoline vapor cannot penetrate the new seals, virtually eliminating evaporative emissions.

New Oil Filter Element

The paper element in the Ecotec 2.2L oil filter has been improved. The engine’s innovative filter design uses a replaceable cartridge without the conventional metal filter can, which traps waste oil that can not easily be removed. The cartridge can also be changed from under the hood, without getting under the car, and it virtually eliminates spillage during replacement. The new element filters particles from the oil more effectively without disrupting oil flow.

Improved Emissions Performance

The Ecotec 2,2L now meets BIN5 tailpipe emissions mandates in all applications. To achieve this standard, the mix of precious metals in the catalytic converter has been reformulated. Metals such as platinum, palladium and rhodium in the converter’s catalytic substrate create the chemical reaction that turns the majority of exhaust emissions into harmless gases and water vapor. With the new intake sealing gaskets, the 2.2L also meets PZEV (Partial Zero Emission Vehicle) Enhanced Evaporation standards.

Overview

The upgrades for 2007 point out an ongoing theme for the Ecotec 2.2L I4: continuous improvement to a ground-breaking engine from a company with a long history of other ground-breaking engines and transmissions.

Since the model year 2000 launch of the Ecotec 2.2L, the innovative strategy behind its versatile design has been validated by successful variants like the Ecotec 2.4L VVT (RPO LE5) and the ultra-high performance 2.0L direct-injection Turbo (RPO LNF). The 2.2L laid the foundation for a line of engines that share core components with minimal casting changes, yet deliver unique performance and market characteristics with a range of displacements, induction and fuel-delivery systems, and front-, rear- drive applications in both cars and trucks.

Introduced in 2000, the Ecotec 2.2L is often referred to as the Global Four Cylinder. It has leveraged GM Powertrain’s worldwide design and engineering capability by drawing on the best practices of technical centers in North America and Europe. It also created a template for subsequent global powertrain development and laid the groundwork for engines such as Powertrain’s global V-6 VVT.

At 305 pounds fully dressed, the 2.2L is the lightest engine GM has produced in its displacement class, and one of the most compact four-cylinders in the world. It features durability enhancements and technology familiar in premium V-type engines, including low-friction hydraulic roller finger valve operation and electronic “drive-by-wire” throttle in most applications. A hydraulic tensioner keeps the timing chain adjusted for life, and extended-life spark plugs deliver 100,000 miles of service. Routine maintenance is limited to oil and filter changes, and even those are made as easy as possible with a paper filter replacement cartridge and GM’s industry-leading Oil Life Monitoring System, which determines oil-change intervals according to real-world operation rather than a predetermined mileage interval.

Every engine in the Ecotec line has aluminum-intensive construction, with dual overhead camshafts (DOHC) and four valves per cylinder. Twin counter-rotating balance shafts cancel the second-order vibration inherent in four-cylinder inline engines, while direct mounting of accessories like the alternator and compressor eliminate common sources of noise, vibration and harshness. Full-circle transmission attachment and a structural oil pan improve powertrain rigidity.

The 2.2L has undergone the toughest and most comprehensive validation process in GM history, passing all of the dynamometer and vehicle tests traditionally run by various GM organizations worldwide. Validation included thousands of miles of real-world road testing in an extreme range of climates. Since the 2.2L’s introduction, virtually every system or component has been reviewed for improvement. Continual development has included optimized rod and main bearing material and shape changes, polymer coated pistons, and a new piston profile that reduces noise. Refinements such as an electrically operated power steering pump have been added to most Ecotec applications. The timing chain tensioner has also been redesigned for quieter operation

For all its design and production efficiencies and multitude of applications, the Ecotec 2.2L succeeds for one reason. It’s a world-class four cylinder engine that delivers excellent performance without sacrificing durability, economy or smooth, quiet operation.

The Ecotec engine variants are built at plants in Tonawanda, N.Y., Spring Hill, Tenn., and Kaiserslautern, Germany.

2007 GM 2.8L V6 VVT (LP1)

2.8L V6 VVT (LP1) CAR ENGINE

2007 Model Year Summary

Smaller Pitch Timing Chain

Dual-Spray Fuel Injectors

Improved Oil Pan

Full Description of New and Updated Features

Smaller Pitch Timing Chain

The 2.8L V6 VVT in the Cadillac CTS has a new timing chain with a smaller pitch (7.7 mm compared to 9.5mm previously) and more links. The chain features an inverted tooth design. The smaller links engage at a lower impact speed, which decreases the noise generated. In conjunction with the new chain, the number of teeth on the sprockets is also increased, increasing the meshing frequency and further reducing noise and vibration.

The new timing chain is a running change that will occur in all of GM Powertain’s V6 VVT engines through the course of the 2007 model year

Dual-Spray Fuel Injectors

New injectors feature two tiny spray nozzles and improve fuel atomization in the combustion chambers compared to single-tip injectors. Developed with Bosch, the dual-spray injectors allow more complete combustion and better emissions management. The new fuel injectors were a running change introduced during the 2006 model year.

Improved Oil Pan

The oil pan on the 2.8L V6 VVT has been stiffened to improve powertrain rigidity and reduce vehicle vibration. The oil pan bolts to the transmission bell housing as well as the engine block, eliminating points of vibration.

Overview

The 2.8L V6 VVT (RPO LP1) shares design values with GM Powertain’s other high feature, global V6 engines, and the results are hard to beat: A market-leading balance of good specific output, high torque over a broad rpm band, fuel economy, low emissions and first-rate noise, vibration and harshness control.

The first V6 VVT was launched in North America in the 2004 Cadillac CTS and SRX at a displacement of 3.6 liters. The 2.8L followed for 2005 as the standard engine in the CTS. The global V6 architecture was developed jointly by GM technical centers in Australia, Germany, the United States and Sweden. The design is based on the philosophy that a true family of global engines provides the best value and performance for the customer and the best return on investment for General Motors. These V6s apply the most advanced automotive engine technology available, from state-of-the-art casting processes to full four-cam phasing to ultra-fast data processing and torque-based engine management. They include exclusive durability enhancing features and require very little maintenance.

The 2.8L V6 VVT’s engine block is sand-mold cast from A319 aluminum, with cast-in iron bore liners, six-bolt main bearing caps and inter-bay breather vents. Compared to the 3.6L V6 VVT, its bore is reduced from 94 mm to 89 mm, and its stroke from 85.6mm to 74.8 mm. The 2.8L’s compression ratio is also reduced slightly to 10:1, compared to 10.2:1 in the 3.6L. With changes in the combustion chamber design and engine controls, the 2.8L operates on regular octane gasoline.

Cylinder heads are also A319 aluminum, with dual overhead cams, four-valve-per-cylinder heads and a silent chain valvetrain that contribute to both smoothness and high output. The 2.8L V6 VVT employs four-cam phasing to change the timing of valve operation as operating conditions such as rpm and engine load vary. The result is linear delivery of torque, with near-peak levels over a broad rpm range and without sacrificing high-rpm horsepower, overall engine response or drivability. The 2.8L V6 VVT generates well over well over one horsepower per cubic inch. Cam phasing also reduces exhaust emissions by optimizing exhaust valve overlap and eliminating the need for a separate exhaust gas recirculation (EGR) system. The 2.8L meets all emissions mandates without complex, weight-increasing emissions control systems such as EGR and air injection reaction (AIR).

Aluminum-intensive construction extends to the pistons, which are manufactured of forged aluminum and considerably lighter than conventional steel pistons. Less weight means less reciprocating mass in the engine, which in turn means less inertia and greater operating efficiency. Moreover, the V6 VVT pistons are crafted with a number of features that enhance durability and reduce noise and harshness, including a high-tech polymer coating and floating wrist pins. The V6 VVT engine family was developed with pressure-actuated oil squirters in all applications. Three jet assemblies in the block hold a pair of oil-squirting nozzles that drench the underside of each piston and the surrounding cylinder wall with an extra layer of cooling, friction-reducing oil. The jets reduce piston temperature, which in turn allows the engine to produce more power without reducing long-term durability. The extra layer of oil on the cylinder walls and wristpin further dampens noise emanating from the pistons, meaning quieter operation.

The oil pan demonstrates extensive efforts to minimize noise and vibration in the V6 VVT. Cast aluminum dampens internal engine noise better than a conventional stamped steel pan; structurally, it is considerably stiffer. The design was optimized with math-based analysis and carefully crafted curves in the pan’s sides and bottom. These reduce the broadcasting or “drumming’’ of noise created as oil flows through the crankcase, and they increase bending stiffness in the pan.

The 2.8L V6 VVT is managed one of the most sophisticated Engine Control Modules available: the Bosch Motronic ME9. It uses a torque-based control strategy, which improves upon throttle-based management systems that rely exclusively on throttle position sensor to manage electronic throttle control. The torque-based strategy measures optimal throttle position, the position of the intake plenum plate, cam phasing positions and other operational parameters and translates that data into an ideal throttle position and engine output, based on the driver’s positioning of the gas pedal.

The ECM provides a limp-home mode for ignition timing, in the event either the crank or cam sensor fails. It also provides coolant loss protection, which allows the V6 VVT to operate safely at reduced power, even after there has been a total loss of engine coolant, so the driver can reach a secure location. The ECM allows a number of other customer-friendly features, including GM's industry-leading Oil Life System, which determines oil change intervals by actual operation parameters, rather than a preset mileage limit.

The cam drive and valvetrain components require no scheduled maintenance. A sophisticated cam-chain tensioner, high-quality cam phasing components and hydraulic lash adjusters are designed to ensure optimal valvetrain performance for the life of the engine with no adjustment. Even perishable components provide extended useful life. The spark plugs have dual-platinum electrodes and a service life of 100,000 miles without degradation in spark density. They’re located in the center of the cam covers, and easy to remove. Extended life coolant retains its cooling and corrosion-inhibiting properties for 100,000 miles in normal use. The two accessory-drive belts are manufactured of EPDM rather than neoprene and should last the same 100,000 miles before replacement is recommended. The oil filter requires only element replacement, and it’s designed to virtually eliminate spillage when the cartridge is removed.

The V6 VVT development and production teams made assembly efficiency a priority. All global V6 variants can be built with no significant casting changes to major components. Core engine components are designed to be common whenever possible. The basic V6 block is used in all vehicle applications, with differences limited to machining. While different vehicles require different oil pans, the pan’s mating surfaces with the engine block and transmission are common in all cases, allowing considerable assembly efficiencies. The net result is streamlined procurement practices, fewer tool changes in the plant, shorter assembly time and improved quality for the customer.

The is 2.8L V6 VVT is built in St. Catharines, Ontario, Canada and Port Melbourne, Australia