Northstar engine series
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| Northstar engine | ||
|---|---|---|
Cooling system Water-cooled | | |
| Output | ||
| Power output | 215–469 hp (160–350 kW) | |
| Torque output | 234–439 lb⋅ft (317–595 N⋅m) | |
| Chronology | ||
| Predecessor | ||
| Successor | ||
The Northstar engine is a family of high-performance 90°
Displacing 4.6 L; 278.6 cu in (4,565 cc) in its basic form, the direct family line transitioned to
.The related Northstar System was Cadillac's trademarked name for a package of performance features introduced in mid-1992 that coupled the 4T80E transmission, a 100,000 mile service interval, road sensing suspension, variable power steering, and 4-wheel disc brakes to the Division's high-output and high-torque Northstar engines.
GM ceased production of the Northstar in 2011. The final cars to receive it, the
Development and features
GM initiated what ultimately became the Northstar's design at Oldsmobile R&D[
Cadillac was developing new models which they hoped would compete against the best luxury cars from BMW, Mercedes-Benz, and Asian rivals like Lexus, Acura, and Infiniti. GM developed a laundry list of items to be included in the Allanté and updated Eldorado and Seville STS, including sophisticated steering, braking, and suspension technologies, and an engine exclusive to "Cadillac" the Division's dealers were clamoring for. This group of features became known as the Northstar System. Central to it was a high-tech V8 with the performance and sophistication to compete with an ever-expanding list of imported challengers.
Capable of producing 300 hp (224 kW) out of its 4.6 L; 278.6 cu in (4,565 cc) displacement, the Northstar featured a cast aluminum 90° V8 block with 4 in (101.6 mm) bore spacing split into unitary upper and lower halves. The lower crankcase assembly supported the crankshaft without conventional main bearing caps. An oil manifold plate with an integrated silicone gasket forms the oil gallery under this. A typical oil change used 7.5–8 US qt (7.1–7.6 L; 6.2–6.7 imp qt) of oil.
GM specified cast-iron
One notable feature advertised at the time was the "limp home" fail-safe mode, which allowed the engine to continue running for a limited time without any coolant. Supplying fuel to only one cylinder bank in turn, the engine would "air cool" the inactive bank. This technique, combined with its all-aluminum construction and large oil capacity, allows the engine to maintain safe temperatures, allowing a Northstar-equipped car to be driven with no coolant for about 100 mi (161 km) without damage. Another unusual feature of some heavily electronic-laden Northstar-equipped cars such as the
Later developments included direct coil-on-plug ignition, roller lifters, and variable valve timing, which can vary intake by up to 40° and the exhaust by up to 50°. VVT was devised for the longitudinal LH2 version, and was not used on the transverse front wheel drive engines due to packaging considerations.[clarification needed]
Northstar series
The engine was introduced in mid-1992 in the 1993
The Northstar was sold exclusively by that name by Cadillac for over a decade before being introduced in the 2004-2005 Pontiac Bonneville and 2006 Buick Lucerne. However, the 4.0 L; 243.8 cu in (3,995 cc) L47 V8 Northstar variant was used in the Oldsmobile Aurora the 3.5L LX5 V6 in the Oldsmobile Intrigue and Oldsmobile Shelby Series 1. The LH2 engine variant received a forged steel crankshaft in October 2003. The LD8 and L37 variants received a forged crankshaft for the 2006 model year. Cadillac had planned to introduce a V12 Northstar this decade, likely for use in the Escalade, but economics and new CAFE standards killed the idea.
Most Northstar engines produce 275 to 300 hp (205 to 224 kW), with power reaching as high as 469 hp (350 kW) in the
All but the supercharged Northstars displaced 4.6 L; 278.6 cu in (4,565 cc) with a 93 mm × 84 mm (3.66 in × 3.31 in) bore and stroke. For better head gasket sealing between cylinders, the supercharged version is de-bored to 91 mm (3.58 in) for a total displacement of 4.4 L; 266.7 cu in (4,371 cc). The block is believed 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 4.6L V8 engine found in models from 1995-2005 were notorious for failure due to a design flaw involving the use of torque-to-yield bolts in the head gasket.[2] Essentially, these type of bolts are stretched beyond their elasticity upon installation, ultimately increasing wear and fatigue on the bolt and decreasing its service life. The high load of the engine would eventually cause these bolts to weaken and loosen in their threads, rupturing the seal and in turn blowing the head gasket.
Northstar System
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 the 1993 Seville and Eldorado.
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)
- Variable valve timing (VVT), 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.
- GM 4T80-E 4-speed automatic transmission
- Road Sensing Suspension (RSS), which monitored damping rates of the shock absorbers every 15 milliseconds, selecting between two settings.
- RSS was available in both standard and CV-RSS (continuously-variable) systems.
- 4-wheel antilock brakes
- Magnasteer speed-variable hydraulic power steeringand magnetized "doughnuts" mounted around the output shaft, which stiffen the steering as vehicle speed increases.
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.
L37
The 4.6 L; 278.6 cu in (4,565 cc) L37 (
The original L37 was specified at 290 hp (216 kW), but 1993 production examples were rated at 295 hp (220 kW). The engine topped out at 300 hp (224 kW) from 1996 through 2004 on the
| Year | Model | Power | Torque |
|---|---|---|---|
| 1993 | Cadillac Allanté | 295 hp (220 kW) @ 5600 rpm | 290 lb⋅ft (393 N⋅m) @ 4400 rpm |
| 1993–1994 | Cadillac Eldorado ETC | 295 hp (220 kW) @ 5600 rpm | 290 lb⋅ft (393 N⋅m) @ 4400 rpm |
| 1995–2002 | 300 hp (224 kW) @ 6000 rpm | 295 lb⋅ft (400 N⋅m) @ 4400 rpm | |
| 1993-1994 | Cadillac Seville STS | 295 hp (220 kW) @ 5600 rpm | 290 lb⋅ft (393 N⋅m) @ 4400 rpm |
| 1995–2004 | 300 hp (224 kW) @ 6000 rpm | 295 lb⋅ft (400 N⋅m) @ 4400 rpm | |
| 1996–2004 | Cadillac DeVille Concours/DTS
| ||
| 2005 | Cadillac DeVille DTS |
290 hp (216 kW) @ 5600 rpm | 285 lb⋅ft (386 N⋅m) @ 4400 rpm |
| 2006–2011 | Cadillac DTS Performance | 292 hp (218 kW) @ 6300 rpm | 288 lb⋅ft (390 N⋅m) @ 4500 rpm |
| 2008–2011 | Buick Lucerne Super |
LD8
The 4.6 L; 278.6 cu in (4,565 cc) LD8 (VIN "Y") 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 LD8 code had been used on all torque-tuned transverse Northstars, even as the exact engine specifications evolved. Compression ratio is 10.3:1 for engines built prior to model year 2000, and 10.0:1 for those built afterwards. The 1998 revision is quieter than previous Northstar engines, due to hydraulic engine mounts, and performs better due to a tuned intake system.
Most LD8 Northstars are rated at 275 hp (205 kW) and 300 lb⋅ft (407 N⋅m).
| Year | Model | Power | Torque |
|---|---|---|---|
| 1994 | Cadillac Eldorado | 270 hp (201 kW) | 300 lb⋅ft (407 N⋅m) |
| 1995–2001 | Cadillac Eldorado ESC | 275 hp (205 kW) @ 5750 rpm | |
| 2002 | 275 hp (205 kW) @ 5600 rpm | 300 lb⋅ft (407 N⋅m) @ 4000 rpm | |
| 1993-1994 | Cadillac Seville SLS | 270 hp (201 kW) | 300 lb⋅ft (407 N⋅m) |
| 1995–2004 | 275 hp (205 kW) @ 5600 rpm | 300 lb⋅ft (407 N⋅m) @ 4000 rpm | |
| 1994 | Cadillac DeVille Concours |
270 hp (201 kW) | 300 lb⋅ft (407 N⋅m) |
| 1995 | 275 hp (205 kW) @ 5750 rpm | ||
| 1996–2001 | Cadillac DeVille |
300 lb⋅ft (407 N⋅m) @ 4000 rpm | |
| 2002–2005 | 275 hp (205 kW) @ 5600 rpm | ||
| 2006–2011 | Cadillac DTS | 275 hp (205 kW) @ 6000 rpm | 295 lb⋅ft (400 N⋅m) @ 4400 rpm |
| 2004–2005 | Pontiac Bonneville GXP | 275 hp (205 kW) @ 5600 rpm | 300 lb⋅ft (407 N⋅m) @ 4000 rpm |
| 2006–2007 | Buick Lucerne CXL (optional)/CXS | 275 hp (205 kW) @ 6000 rpm | 295 lb⋅ft (400 N⋅m) @ 4400 rpm |
LH2 (VIN "A")
The 4.6 L; 278.6 cu in (4,565 cc) 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 STS, SRX, and XLR, as well as receiving continuously variable valve timing on both intake and exhaust sides. The RWD (LH2) Northstar produces 320 hp (239 kW) and 315 lb⋅ft (427 N⋅m). The addition of variable valve timing enables most of the increase in power from the L37 and LD8 Northstars.
| Year | Model | Power | Torque |
|---|---|---|---|
| 2004–2009 | Cadillac SRX | 320 hp (239 kW) @ 6400 rpm | 315 lb⋅ft (427 N⋅m) @ 4400 rpm |
| 2004–2009 | Cadillac XLR | 310 lb⋅ft (420 N⋅m) @ 4400 rpm | |
| 2005–2010 | Cadillac STS | 315 lb⋅ft (427 N⋅m) @ 4400 rpm | |
| 2007–2009 | Cadillac SLS (China) |
LC3
A 4.4 L; 266.7 cu in (4,371 cc)
| Year | Model | Power | Torque |
|---|---|---|---|
| 2006–2009 | Cadillac STS-V |
469 hp (350 kW) @ 6400 rpm | 439 lb⋅ft (595 N⋅m) @ 3900 rpm |
| 2006–2009 | Cadillac XLR-V | 443 hp (330 kW) @ 6400 rpm | 414 lb⋅ft (561 N⋅m) @ 3900 rpm |
L47
The L47 Aurora engine was a special V8 designed for the Oldsmobile Aurora, based on the Northstar engine, used during the 1995-1999 and 2001-2003 model years. It is a DOHC 4.0 L; 243.8 cu in (3,995 cc) V8 which produced 250 hp (186 kW) and 260 lb⋅ft (353 N⋅m) of torque. The bore and stroke was 87 mm × 84 mm (3.43 in × 3.31 in). The L47 had a 10.3:1 compression ratio and used premium fuel.
Although most of the Northstar's features, including the coolant loss system, remained intact, the decreased bore increased weight unacceptably. To reduce it, Oldsmobile used a one-piece glass-filled thermoplastic
An early version or
The Aurora engine was introduced in 1994 for the 1995 model year, and
| Year | Model | Power | Torque |
|---|---|---|---|
| 1995–2003 | Oldsmobile Aurora | 250 hp (186 kW) @ 5600 rpm | 260 lb⋅ft (353 N⋅m) @ 4400 rpm |
| 1999–2005 | Shelby Series 1 | 320 hp (239 kW) @ 6500 rpm | 290 lb⋅ft (393 N⋅m) @ 5000 rpm |
LX5 (Shortstar)
The LX5 is a DOHC
Although it has a 90° V-angle like the Northstar, the engine block was engineered from scratch, so bore centers are different. It has chain-driven
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 before GM discontinued the Shortstar in favor of their current flagship V6, the High Feature engine, in 2004.
The LX5 was entirely different from any other V6 in the GM inventory - the only other DOHC V6 engines ever offered by GM included the
| Year | Model | Power | Torque |
|---|---|---|---|
| 1999–2002 | Oldsmobile Intrigue | 215 hp (160 kW) @ 5600 rpm | 234 lb⋅ft (317 N⋅m) @ 4400 rpm |
| 2001–2002 | Oldsmobile Aurora |
The 3.5L LX5 was on the Ward's 10 Best Engines list for 1999 and 2000.
Notes
- ^ "Report: GM's venerable Northstar going out of production in July, replacement not yet announced". Autoblog. Archived from the original on 2011-02-21. Retrieved 2012-06-04.
- ^ Njagi, Kevin (2022-09-26). "10 Cheap Sedans That Will Bankrupt You With Maintenance Bills And Repairs". HotCars. Retrieved 2023-09-21.
- ^ Weitzman, Larry (2001).The Aurora by Oldsmobile (2001), Better in every respect. Autochannel. Retrieved on June 28, 2009.
References
- Frank Markus. "1993 Technical Highlights". Car and Driver (October 1992): 59–60.
- "Technical Highlights". Car and Driver (October 1993): 115.
- Joel D. Pietrangelo. "Northstar is heart of Allante re-do for '93 - V-8 engine, General Motors' Cadillac Motor Car Div.'s new model roadster". Ward's Auto World(February 1992).
External links
