Northstar Engine Series - Northstar Series

Northstar Series

The engine was introduced in mid-1992 in the 1993 Cadillac Allanté, eventually ended up in most Cadillac automobiles, but is now nearly phased out of most Cadillac models. The original Northstar Allanté also introduced the Northstar System which included traction control, adaptive suspension, and antilock brakes. Early Northstar required premium grade gasoline to run safely.

The Northstar was sold exclusively by Cadillac for over a decade before being introduced in the 2004-2005 Pontiac Bonneville and 2006 Buick Lucerne. However, the 4.0L L47 V8 variant was used in the Oldsmobile Aurora and the 3.5L LX5 V6 in the Oldsmobile Intrigue. The engine received a forged steel crankshaft in October 2003. Cadillac had planned to introduce a V12 Northstar this decade, likely for use in the Escalade, but economics and new CAFE standards had killed the idea.

Most Northstar engines produce 275 hp (205 kW) to 315 hp (235 kW). The engines were revised for 2000 with coil-on-plug ignition and roller follower valvegear for improved fuel economy and reduced emissions. Though power output did not change, this update eliminated the need for premium fuel.

All but the supercharged Northstars displaced 4.6 L (279 cu in) with a 93 mm (3.7 in) bore and 84 mm (3.3 in) stroke. For better head gasket sealing between cylinders, the supercharged version is de-bored to 91 mm (3.6 in) for a total displacement of 4.4 L (266 cu in). The block is said to be capable of expansion up to 5.4 L, though no such engine has been produced.

The Northstar was on the Ward's 10 Best Engines list for 1995, 1996, and 1997.

The Northstar System was Cadillac's trademarked name for a package of automobile performance features. Introduced in mid 1992 on the 1993 Cadillac Allanté and later on that year's Seville and Eldorado, the Northstar name continues in use to this day, although only in the Cadillac DTS, since it was announced that the final production year of the STS will use the 3.6L V6 engine only.

The Northstar System included the following components:

• • L37 high-output 300 hp (224 kW) and 295 lb·ft (400 N·m)
  • LD8 high-torque 275 hp (205 kW) and 300 lb·ft (407 N·m)
• GM 4T80-E 4-speed automatic transmission
• Road Sensing Suspension

RSS was available in both standard and CV-RSS (continuously-variable) systems. It monitored damping rates of the shock absorbers every 15 milliseconds, selecting between two settings.

• 4-wheel disc brakes with Bosch antilock brakes
• Magnasteer speed-variable power steering

Magnasteer combines conventional hydraulic power steering and magnetized "doughnuts" mounted around the output shaft, which stiffen the steering as vehicle speed increases.

The later versions of the Northstar engine included the 4.6L 320 hp (239 kW) and 315 lb·ft (427 N·m) LH2 which began in 2004, and supercharged 4.4L 469 hp (350 kW) LC3 created for the STS-V which are detailed below.

General Motors employed a continuously variable system for the Cadillac Northstar System, VVT (Variable Valve Timing). The Northstar VVT provides a continuously variable system throughout the rpm range, increasing fuel economy. GM engines use the double overhead cam, varying both intake and exhaust for better performance.