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GM debuted the XV12 Northstar prototype in the Cadillac Cien show car at the January North American International Auto Show. The powerplant, which features many advanced advanced technologies is rumored to be in the future of the STS, Escalade, and possibly a Cadillac supercar. Also to many's shock the engine has even been mentioned for use in a $100K Super Corvette! Below is GM's official release on the new engine.

 

PEBBLE BEACH, Calif. - General Motors' innovative V12 concept engine, called Northstar XV12, showcases several advanced technologies in a fuel efficient, V8-like package.

 

This all-new high-technology, high-output 12-cylinder powerplant, featured in the 2002 Cadillac Cien mid-engine concept car, is a 60-degree, all-aluminum dual overhead cam (DOHC) four-valve engine. It displaces 7.5 liters and produces 750 horsepower (560 kW) and 450 lb-ft of torque (610 Nm), yet is packaged in the size of a V8, and able to deliver excellent fuel economy. The engine has integrated advanced technologies for the future developed by GM Powertrain's Advanced Engineering, and assembled in a compact package that GM engineers refer to as "small on the outside, big on the inside."

 

The Northstar XV12 represents a unique combination of a nod to the past and a glimpse of the future.

 

"The Northstar XV12 provides a realistic look at what could power an assault on the high-end, premium automotive segment," said Fritz Indra, GM Powertrain executive director of advanced engineering. "At the same time it showcases a wealth of new technologies under development at GM Powertrain, many of which will eventually find their way into GM engines of all shapes and sizes."

 

GM historically has had a vision to provide unmatched power, refinement, exclusivity and technical excellence in its powertrains. When GM's Cadillac division was solidifying its standing as the "Standard of the World" in the 1920s and 1930s, it did so powered by notable V12 and V16 engines.

 

The Northstar XV12 is the same length as GM's Vortec 8100 V8, and it has the approximate width and height as the Northstar 4.6-liter and Vortec 6000 V8s.

 

"The packaging was probably the biggest challenge we faced, because from the outset we wanted to fit the V12 inside the package of a V8," said Steve Kowalk, GM Powertrain project manager for the Northstar XV12. "We focused on keeping the size down to fit as many different types of vehicles as possible, while maximizing displacement, and then using Displacement on Demand to deliver the required power at all times. We also minimized cylinder bore wall thickness to 7 millimeters and used a rear cam drive to create a more compact package and enable a lower hoodline."

 

GM's Displacement on Demand enables the V12 engine to run seamlessly on six cylinders at times to maximize fuel savings, and is only one of several technological advancements showcased on the Northstar XV12. Some of the high-tech features included in Northstar XV12's capabilities:

 

Displacement on Demand

 

The cylinder shutdown is enabled through valve deactivation, which is performed by a compact switchable tappet. Cylinder de-activation occurs on the right-hand bank only, which allows the engine to run as a perfectly balanced inline 6-cylinder. The system deactivation and reactivation has a quick response time and the oil system and solenoid layout allows valve switching capability at up to 6000 rpm. In May 2001, GM announced that it will implement Displacement on Demand in its trucks and SUVs beginning in 2004.

 

Direct Injection Gasoline

 

Using a direct-injection gasoline combustion system provides an increase in engine power and also improves fuel economy and cold-start hydrocarbon emissions. The multiple injection set-up also improves emissions and performance through faster catalyst light-off. The single fluid high-pressure fuel injector is centrally located in the combustion chamber, and sprays the fuel vertically down to the piston.

 

Variable Cam Phasing

 

The use of variable cam phasing helps the Northstar XV12 achieve 90 percent of its maximum torque at 1500 rpm, improves combustion stability at idle, improves fuel economy by reducing pumping losses and can be used to speed up catalyst light-off to significantly improve emissions. It provides internal exhaust gas recirculation (EGR), which is more reliable and cost-effective than an external EGR set-up.

 

Variable Intake Manifold

xv12.jpg

 

The Northstar XV12's three-stage variable induction system with tuned primary and secondary pipes results in a flat torque curve. It's a simple, compact and reliable design. Electric variable intake valve actuators enable rapid changes in manifold geometry over conventional pneumatic actuators.

 

Rear Chain Timing Drive

 

Many of the engine's accessories are run off the rear chain timing drive, creating opportunities for better packaging by eliminating the need for a front engine accessory drive and reducing the engine's overall length, as well as the height of its front end. The robust yet quiet-running chain drives the engine's camshafts, high-pressure fuel pump, oil pump, and hydraulic power-assist steering pump, and also has the potential to drive the water pump and air conditioning compressor.

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Guest Tht1KSguy

Ahhh... damn dinky 17" monitor at work... had to get home to the 19" to see it smile.gif

It's pretty sad when you're a designer that your home computer is better than the one you use for 8hrs a day at work. Remind me to convince my boss to let me telecommute.

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What's the date on that article you quoted? Last I read, the Cien was shelved, mostly due to the cost of developing that engine (among other costly parts). They did emphasize "shelved" and not killed off though. It's part of the new Bob Lutz GM culture. All projects must be able to show profit (which only makes sense). But stuff can be held until a business case makes sense. The current economy just doesn't support the effort.

 

There was some european super car that was slated to use that engine and they were forced to look elsewhere.

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  • 5 years later...

Leave it to the Cadillac division to come up with the innovative stuff. They had a V12 in the works in 1968 based on the 472-500 cid V8s that was shelved/killed by CAFE and EPA rules at that time. It was going to be a 12 liter 600 HP low RPM torque monster, but the only one I know of still in existence is in the Cadillac museum near Detroit (and it's gold plated, no less).

Steve

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