2010 Northstar 4.6L V-8 (L37/LD8/LH2)
Northstar 4.6L V-8 (L37/LD8/LH2) Car Engine
SUMMARY OF NEW OR CHANGED FEATURES
Carryover from 2009 model year
FULL DESCRIPTIONS OF NEW OR CHANGED FEATURES
Carryover STATE-OF-THE-ART E67 CONTROLLER AVAILABLE for ALL APPLICATIONS:
The E67 electronic control module that was added to the front-drive applications, the Buick Lucerne and Cadillac DTS, for the 2006 Model Year became the standard controller in all of the applications in 2007,which added the STS performance sedan, and the XLR roadster,and SRX crossover SUV. The controller continues for Cadillac DTS and Buick Lucerne for 2010 model year.
As in 2009, Mobil One synthetic oil will be used as the specified oil of choice for all 2010 Cadillac Premium V8 engines in both RWD and FWD applications to achieve extended oil change intervals. This interval as much as 13,000 miles, for all PV8 engines in Cadillac (maximum interval), which is dependent on the owner's driving habits/schedule (city & highway driving mix). FWD Buick Premium V-8's will continue to use mineral oil.
OVERVIEW
The Northstar V-8 was the basis for a technological renaissance at Cadillac, lending its name to an entire automotive system that includes the most advanced traction-enhancement, suspension and anti-skid electronics in the world when it was launched in the 1993 Cadillac Allante. The 90-degree Northstar was the first all-American dual-overhead cam aluminum V8 engine. Sixteen patents protected its advanced technologies; seven more have been granted since. In 1994, the original Northstar (RPO L37) was joined by a second version (LD8). Different camshafts and cam lobe profiles provided different power curves and very different driving characteristics. The L37 is more responsive, higher revving, with more peak horsepower and a higher redline (6500 rpm vs. 6000 rpm). The LD8 puts more emphasis on quick launch and part-throttle response, with greater peak torque. The L37 and LD8 are used in front-drive applications; the LH2 is the rear- and all-wheel-drive variant.
The Buick application uses the LD8 version of the 4.6L, which is defined by sportier throttle response in the Lucerne model , while the DTS is available with either the comfort-tuned L37 or the LD8. Beginning in 2008, the L37 was released for the new Buick Lucerne “Super” offering. This model will continue for the 2010 model year.
Electronic “drive-by-wire” throttle eliminates a mechanical link between the accelerator pedal and throttle plate. The 4.6L V-8 beginning in the 2006 Model Year has no throttle cable; instead, a potentiometer at the pedal measures pedal angle and sends a signal to the engine control module (ECM); the ECM then directs an electric motor to open the throttle at the appropriate rate and angle. Electronic Throttle Control (ETC) is integrated with the ECM, which uses data from multiple sources, including the transmission’s shift patterns and traction at the drive wheels, in determining how far to open the throttle. With this data, the 4.6L V-8 effectively anticipates the driver’s demands, whether it’s a slow-speed parking maneuver or wide-open throttle operation on the open road, and responds appropriately. ETC delivers outstanding throttle response and greater reliability than a mechanical connection. Cruise control electronics are integrated in the throttle, reducing the amount of wiring required, further improving reliability and simplifying engine assembly.
Also in 2006, the latest generation electronic engine control module, E67, was added to the front-drive versions of the 4.6L V-8 to better process signals necessary for the new electronic throttle control and other functions such as variable valve timing. For 2007, all variants use the E67 controller.
To improve emissions performance for the 2006 Model Year, the fuel system was changed to a “returnless” system, meaning that there is no complete loop in the path of the fuel from the fuel tank to the engine and back to the tank. The return regulator is therefore eliminated from the fuel rail. Bosch EV14 injectors were added to the front-drive applications of the 4.6L V-8, common to those used in the XLR and SRX versions of the 4.6L V-8.
Variable valve timing for the engine’s intake and exhaust valves offers flexibility, fuel economy and reduced emissions, making the engine an efficient performer. The four-cam variable valve timing is a key element in the V-8’s control strategy, giving the engine wide-ranging flexibility. Additionally, electronic throttle control effectively coordinates the driver’s intentions with the actions of the various control components.
In Cadillac models, the 4.6L Northstar V-8 VVT is available with the Hydra-Matic 6L50 six-speed electronically controlled automatic transmission with Driver Shift Control. In the Cadillac XLR, a unique torque-tube and rear-mount location of the slightly larger 6L80 transmission helps give the roadster perfect 50-50 weight distribution. The 6L80 also gives drivers the ability to override normal automatic gear selection for more control during aggressive driving. Driver Shift Control (DSC) switches from automatic to clutchless manual shifting with a flick of the gear selector, allowing up- or downshifts with a quick tap on the lever.
Since the engine’s introduction, GM has steadily improved this premium V-8 and continued to push its technological envelope. In 2004, GM's 4.6-liter Northstar V-8 made the transformation to be used in FWD and RWD/AWD applications. FWD applications benefited from a new, stronger forged steel crankshaft, a more powerful engine management computer, and several other key refinements that improved performance.
Also in 2004, the Northstar family of engines benefited from a host of new technologies and engineering features. For example, the LH2 Northstar debuted in the 2004 Cadillac XLR and SRX models, and in 2005 became optional in the 2005 Cadillac STS. Normally, a myriad of changes are required to adapt an existing engine to a new vehicle. In the case of the STS, only a different battery cable was required to enable the LH2 to bolt into an STS.
In the transition from FWD to RWD/AWD applications, the Northstar went from being transversely mounted to longitudinally mounted. Changes were major, and included the LH2 gaining variable valve timing (VVT), electronic throttle control (ETC), a boost in compression, a stronger engine block, a more powerful engine controller, polymer-coated pistons, high-performance exhaust valves, and a host of other technical enhancements. In total, the LH2 gained a five-percent power advantage over the FWD L37 Northstar.
The Northstar V-8s stand among the world’s finest engines. With continuing improvements, the Northstars offer world-class performance and sustained high-speed durability throughout the world’s most demanding operating environments. The Northstar V-8s run with the world’s best. Measured by fuel economy, maintenance requirements or horsepower per liter of displacement, they stand up well when compared to comparable V-8 engines from around the world.
