GM Premium V engine

Automotive

GM Premium V engine

The Premium V family of automobile engines is General Motors' modern 90° v engine architecture. The family is most associated with Cadillac's Northstar V8, but the family has also seen use at Oldsmobile (as the Aurora L47 V8 and "Shortstar" LX5). Recently, Premium V engines have been used at Pontiac and will soon be used by Buick (in the Lucerne) and Alfa Romeo (in the US-market Kamal).

Northstar

The engine was introduced in 1992 in the Cadillac Allante and continues to be used in the Cadillac STS, Cadillac SRX, and Cadillac XLR. It was sold exclusively by Cadillac for over a decade before being introduced in the Pontiac Bonneville for 2004, though the L47 V8 variant was used in the Oldsmobile Aurora and the 3500 LX5 V6 in the Oldsmobile Intrigue. Cadillac is planning to introduce a V12 Northstar this decade.

The original Northstar Allante also introduced the Northstar System which included traction control, adaptive suspension, and antilock brakes.

The all-aluminum Northstar features Dual-Overhead Cams, Variable Valve Timing, and other modern technologies. The VVT system can vary intake by up to 40° and the exhaust by up to 50°. Most Northstar engines produce 275 to 315 hp (205 to 235 kW). The engine displaces 279 in³ (4645 cc) from a 3.66 in (93 mm) bore and 3.31 in (84 mm) stroke. The engine got a forged steel crankshaft in 2003. The block can be expanded up to 5.4 L though no such engine has been produced.

The Northstar block's bellhousing bolt pattern is substantially similar that found on the GM/Isuzu 60-degree V6 engine family [1] (http://myweb.cableone.net/bcanderson/trooper/AuroraSwap.html). One bolt hole location is different, and the starter is located in the valley between cylinder banks rather than on the side of the block. This fact raises interesting possibilities for using this engine family for purposes other than originally intended; if one can find a transmission with a version that bolts to the GM 60-degree family, one can more easily transplant the Northstar engines into other FWD or RWD vehicles. Some possibilities are: GM 700R4; Aisin-Warner transmissions whose bellhousing-to-transmission pattern is shared with the Jeep AX-5, AX-15, and NV3550 transmissions (various Toyota G, R, W, and Isuzu AR models).

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

L37

The L37 was the original Northstar. It is tuned for responsiveness and power, while the later LD8 is designed for more sedate use. The L37 topped out at 300 hp (224 kW) in 2002 on the STS and ETC models, making these the most powerful front wheel drive cars ever built.

Vehicles using the L37 include:

• 1993 Cadillac Allante
• Cadillac DeVille Concours
• Cadillac Seville STS
• Cadillac Eldorado ETC

LD8

The LD8 is a transverse V8 for front wheel drive cars. Introduced in 1994, it is designed to provide more torque than the high-revving L37. The 1998 revision is quieter (thanks to hydraulic engine mounts) and performs better (thanks to a tuned intake system) than previous Northstars. It produces 275 hp and 300 ft.lbf.

Vehicles using the LD8 include:

• Cadillac DeVille
• Cadillac Eldorado
• Cadillac Seville SLS
• Pontiac Bonneville GXP

LH2

The Northstar was designed originally for transverse front wheel drive applications. It was modified substantially in 2004 for longitudinal rear- and all wheel drive use in the SRX and XLR. The RWD (LH2) Northstar is good for 315hp (235kW) and 310ft.lb (420Nm).

Vehicles using the LH2 include:

• 2004 Cadillac SRX
• 2004 Cadillac XLR
• 2004 Cadillac STS

Supercharged

A 4.4 L supercharged Northstar is used in the 2005 Cadillac STS-V. The bore was reduced for increased strength. Variable valve timing is used on both the intake and exhaust sides.

Applications:

• 2005 Cadillac STS-V

L47

The L47 Aurora engine was a special V8 designed for the Oldsmobile Aurora, based on the Northstar engine. It is a DOHC 4.0 L (3995 cc) V8 which produced 250 horsepower (186 kW) and 260 ft.lbf (353 Nm) of torque. The bore is 87 mm and the stroke is 84 mm.

A special version of this engine was used as one of the two engines available to Indy Racing League competitors at the inception of that automobile racing promotion (the other engine was a modified Infiniti V8).

The Aurora engine was introduced in 1994 for the 1995 model year, and General Motors has not used this engine since the demise of the marque in 2004.

LX5

The 3500 LX5 V6 is a DOHC engine from Oldsmobile, introduced in 1999 with the Oldsmobile Intrigue. It was produced by the Premium engine group at GM and was thus called the Premium V6, or PV6, while it was being developed. It is based on the L47 Aurora V8, which is itself based on the Northstar engine, so engineers called it the Short North, though Oldsmobile fans have taken to calling it the Shortstar.

It is not a simple cut-down V8. Although it has a 90° vee-angle like the Northstar and Aurora, the engine block was engineered from scratch, so bore centers are different. It has chain-driven dual overhead cams and 4 valves per cylinder, but is an even-firing design with a split-pin crankshaft similar to the modern GM 3800 engines. The LX5 displaced 3.5 L (3473 cc) and produced 215 hp (160 kW) and 230 ft.lbf (312 Nm). Bore is 89.5 mm and stroke is 92 mm.

The cost of building this engine was high, and it was not used in many vehicles. It was said at the time that a family of premium V6s would follow, with displacements ranging from 3.3 L to 3.7 L, but only the LX5 was ever produced. It was entirely different from any other V6 in the GM inventory, and as with the Aurora V8, production stopped with the demise of Oldsmobile.

This engine was used in the following:

• 1999 Oldsmobile Intrigue
• 2001-2002 Oldsmobile Aurora

The 3500 LX5 was on the Ward's 10 Best Engines list for 1999 and 2000.

See also

• Cadillac V8 engine
• List of GM engines
• Technical article from AutoSpeed (http://www.autospeed.com/cms/A_1569/article.html)
• Ward's article (http://waw.wardsauto.com/ar/auto_general_motors_corp_3)