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It is meant to be used as a guide; please use the information at your own risk.
Last Updated: May 20, 2009

Overview:

The Quad 4 (called Twin Cam after 1995) was a DOHC and SOHC straight-4 automobile engine produced by General Motors' Oldsmobile division.

The LD2 was the standard version of the Quad 4, and was the first incarnation of the Quad 4. It was a lower output version of the Quad 4 when compared to the LGO or High Output Quad 4. There was a transitional version of the LD2 in 1995 that appeared in the 1995 Pontiac Sunfire GT, Chevrolet Cavalier Z24, Pontiac Grand Am SE, and Oldsmobile Achieva.

The LD9 Twin Cam was a 2.4L Quad 4 variant with balance shafts, debuting in 1996. Bore was decreased from 92 mm to 90 mm and stroke increased from 85 mm to 94 mm for better torque, and power was increased to 150 hp (112 kW). This engine received a minor update halfway through the 1999 model year that eliminated the EGR, increased the compression ratio from 9.5:1 to 9.7:1, and switched from low impedance fuel injectors to high impedance.

The history of this motor lies deep within the Quad 4 motor. The Quad 4 was a DOHC straight-4 automobile engine produced by General Motors' Oldsmobile division in the 1990s. It was a modern engine for the time, but was criticized for roughness. Balance shafts were added in 1995, also known as a transitional year from the quad 4 to the renamed TWIN CAM variant, in 1996 2.4 (LD9) the complete engine makeover was accomplished. The name is derived from the engine's four cylinders and four valves per cylinder layout. There was a single overhead camshaft variant that made production as well, albeit for a brief time. The Quad 4 used an iron block and an aluminum head. The Quad 4 debuted in 1987 and was replaced after 2002 by the Ecotec.

Quad 4 engines were produced at Oldsmobile's Delta Township, Michigan plant. In recent years, it has gained a minor following in hot rodding circles as a period style engine (which looks like a 1930's Offenhauser twin cam unit).
– Source: Wikipedia

One of the best known articles comparing the Quad 4 and Twin Cam: http://www.babcox.com/editorial/ar/ar49935.htm


Images:

LD9 'Twin Cam' Engine (Side View) LD2 'Quad 4' Engine (Side View)



General Engine Data:

- Engine Type: Inline 4 Cylinder
- Displacement: 2.4 Liter (146 CID)
- RPO: LD9
- Bore: 90 mm 3.54 in
- Stroke: 94 mm 3.70 in
- Compression Ratio: 9.5:1 (96-98)/ 9.7:1 (99-02)
- Firing Order: 1-3-4-2
- Horse Power: 150 @ 5600 rpm
- Torque Rating: 155 @ 2400-4400 rpm
- Oil Pressure @ 3000 RPM 207 Kpa 30 psi min.
- Oil Pressure @ 900 RPM 69 Kpa 10 psi min.
- Recommended octane: 87
- Fuel Tank Capacity: 14.1-15.2 gal.
- EPA Mileage Estimates: (City/Highway):
    Manual: 23 mpg / 33 mpg
    Automatic: 22 mpg / 30 mpg
- Fuel Delivery: Sequential Fuel Injection (SFI)
- Thermostat opening temperature 180 degrees F
- Emissions: Low emissions vehicle equipped with single Catalyst


Fluids and Capacities:

All capacities are approximate; add fluid as necessary.

- Brake Fluid: Delco Supreme 11 or DOT-3 Equivalent
- Cluch Fluid: Delco Supreme 11 or DOT-3 Equivalent
- Engine Oil Type - SAE 5w30
- Engine Oil Capacity - 4 qts
- Coolant - Dexcool antifreeze – 50/50 mix with drinkable water - Coolant Capacity - 10.7 quarts
- Auto trans fluid - DEXRON-III Automatic Transmission Fluid
- Auto trans fluid capacity – 3-spd transaxles: 7.0 qts / 4-spd transaxles: 9.5 qts
- Manual trans fluid:
    1995-1999 - Syncromesh Transmission Fluid (GM Part Number 12345349)
    2000-2002 - DEXRON-III Automatic Transmission Fluid
- Manual trans fluid capacity:
    1995-1999 - 2.0 qts
    2000-2002 - 1.8 qts
- Refrigerant: R-134a
- Power Steering Fluid: GM p/n 1050017
- Chassis grease: SAE NLGI no. 2 chassis grease

Brief Engine Differences:

96 Model Year
- Engine had different oil passages, and water-pump problems
- Large starter
- One wire front O2 sensor
- Low impedance injectors
- 12465154 (Version 1a) no longer offered
- EGR valve
- Dished pistons
- 9.5:1 CR
- Large knock sensor
- Head casting number is 683-18

97-98 Model Year
- Oil passages and water-pump problems lessen
- Large starter
- One wire front O2 sensor
- Low impedance injectors
- EGR valve
- Dished pistons
- 9.5:1 CR
- Large knock sensor
- Head Casting number is 683-18

97-98 Chevrolet, Pontiac J & N (LD9)(2.4T)
Part # 12462258 Version 1b
Application
1997-98 Chevrolet, Pontiac J (LD9)(2.4T)
1997-98 Chevrolet, Pontiac, N (LD9)(2.4T)
1997-98 Oldsmobile, Buick
1999 Pontiac N (LD9)(2.4T)
  12462258 Version 1b replaces: 12465154 Version 1a
  Order 11516479 self-taping screw for Camshaft Position Sensor. For 2nd design, see 12465154.
  You can use either version 1a, 1b, or 2 in your car with little modification.

99 model year
- Smaller starter
- One wire first O2 sensor
- High impedance injectors
- No EGR valve
- Flat top pistons
- 9.7:1 CR
- Better intake manifold design. Doesn’t have flange on the inside plenum like 00-02 years.
- New oiling passages
- Small knock sensor
- Head casting number is 779
- New style water-pump

00-02 model year
- Smaller starter
- Two wire front O2 sensor
- High impedance injectors
- No EGR valve
- Flat top pistons
- 9.7:1 CR
- New oiling passages
- Small knock sensor
- Head casting number is 779
- New style water-pump
- Belt tensioner changed

01 model year changes
- Received a "higher capacity" Catalytic Converter
- Redesigned starter motor


Torque Specifications

NOTE: some specs are FOOT pounds, some are INCH pounds, do not confuse the two. And keep in mind some common sense is your best friend - if you come across something that says valve cover is torqued to 75 lb ft, common sense should tell you that is way to much. Torque spec listings are not always 100% accurate, just use your head.

- Balance Shaft Cover Nut and Bolt........................................................................115 lb in
- Balance Shaft Driven Sprocket Bolt (left hand thread).........................................30 lb ft + 45°
- Balance Shaft Housing Bolts 8 mm hex................................................................89 lb in + 40°
- Balance Shaft Housing Bolts 10 mm hex..............................................................11 lb ft + 40°
- Balance Shaft to block Bolts 13 mm hex...............................................................18 lb ft + 70°
- Balance Shaft to block Bolts 15 mm hex............................................................... 39 lb ft
- Balance Shaft to Block Bolts 18 mm hex............................................................. 30 lb ft + 60°
- Camshaft (exhaust) Rear Cover............................................................................124 lb in
- Camshaft Position Sensor Bolt............................................................................ 89 lb in
- Camshaft Sprocket to the Camshaft Bolt.............................................................52 lb ft
- Connecting Rod Nuts............................................................................................18 lb ft + 80°
- Coolant Bleeder Valve - Fully Driven, Seated, Not Stripped
- Coolant Outlet to Cylinder Head..........................................................................19 lb ft
- Coolant Pump Cover to the Block........................................................................19 lb ft
- Coolant Pump to the Coolant Pump Cover..........................................................124 lb in
- Coolant Pump to the Timing Chain Housing........................................................19 lb ft
- Crankshaft Balancer to the Crankshaft..................................................................129 lb ft + 90°
- Crankshaft Bearing Cap Bolts................................................................................15 lb ft + 90°
- Crankshaft Position Sensor to Block.....................................................................80 lb in
- Cylinder Head Bolts Refer to Procedure
- Cylinder Head Threaded Plug............................................................................... 19 lb ft
- EGR Pipe to the EGR Adapter.............................................................................19 lb ft
- Engine Coolant Air Bleed Pipe ..............................................................................124 lb in
- Engine Coolant Air Bleed Pipe Nut........................................................................31 lb ft
- Engine Coolant Temperature Gauge Sensor to the Cylinder Head - Fully Driven, Seated, Not Stripped
- Engine Coolant Temperature Sensor to the Coolant Outlet....................................97 lb in
- Engine Lift Bracket..................................................................................................68 lb ft
- Engine Mount Bracket Adapter to Block Bolt Auto Trans.................................... 44 lb ft + 60°
- Engine Mount Bracket Adapter to Block Bolt Manual Trans..................................44 lb ft + 60°
- Engine Mount (right hand side) to the Body Support Bolt..................................... 49 lb ft
- Engine Mount (right hand side) to the Body Support Nut...................................... 32 lb ft
- Engine Mount (right hand side) to the Engine Mount Bracket Bolts.......................46 lb ft
- Engine Mount Strut..................................................................................................74 lb ft
- Engine Mount Strut Bracket Bottom Bolts.............................................................. 96 lb ft
- Engine Mount Strut Bracket Front Bolts..................................................................49 lb ft
- EVAP Canister Purge Valve Solenoid Bracket Bolt..................................................72 lb in
- Exhaust Manifold Brace to the Exhaust Manifold Bolt.............................................41 lb ft
- Exhaust Manifold Brace to the Oil Pan Nuts............................................................19 lb ft
- Exhaust Manifold to the Cylinder Head Nut............................................................11 lb ft
- Exhaust Manifold to the Cylinder Head Studs......................................................... 97 lb in
- Exhaust Manifold Upper Heat Shield to the Manifold Bolts...................................124 lb in
- Flywheel to Clutch Cover .....................................................................................15 lb ft + 45°
- Flywheel to the Converter.......................................................................................49 lb ft
- Flywheel to the Crankshaft....................................................................................22 lb ft + 45°
- Front Cover to the Timing Chain Housing................................................................106 lb in
- Fuel Pipe Bracket to the Camshaft Housing.............................................................11 lb ft +30°
- Fuel Pipe to the Fuel Rail Nut...................................................................................22 lb ft
- Fuel Rail to the Camshaft Housing............................................................................19 lb ft
- Ignition Coil and Module Assembly to the Camshaft Housings...............................16 lb ft
- Intake Manifold to the Cylinder Head Bolts/Nuts....................................................18 lb ft
- Intake Manifold to the Cylinder Head Studs........................................................... 97 lb in
- Knock Sensor.............................................................................................................15 lb ft
- Oil/Air Separator To Block Bolts..............................................................................18 lb ft
- Oil Dipstick Tube Bolt/Screw...................................................................................71 lb in
- Oil Filter Connector to the Block..............................................................................21 lb ft
- Oil Filter to the Block 3/4 to one complete turn after gasket contact
- Oil Pan Bolts.............................................................................................................18 lb ft
- Oil Pan Bolts, Second Set.........................................................................................106 lb in
- Oil Pan Drain Plug.....................................................................................................19 lb ft
- Oil Pan Studs ...........................................................................................................19 lb ft
- Oil Passage Plug Bolt................................................................................................ 22 lb ft
- Oil Passage Plugs, 1/4x18 ...........................................................................................15 lb ft
- Oil Passage Plugs, 3/8x18............................................................................................22 lb ft
- Oil Passage Plugs, Block 1/8x27................................................................................89 lb in
- Oil Pressure Switch......................................................................................................124 lb in
- Oil Pump Cover to the Oil Pump Housing - Short Bolt............................................89 lb in
- Oil Pump to the Balance Shaft Housing - Long Bolts..............................................106 lb in
- Oxygen Sensor To Exhaust Manifold .........................................................................31 lb ft
- Power steering Pipe to the Pump Nut........................................................................20 lb ft
- Power steering Pump to the Cam Carrier Bolts.........................................................19 lb ft
- Rear Crankshaft Seal Housing to Block.................................................................... 106 lb in
- Spark Plugs to the Cylinder Hea...............................................................................13 lb ft
- Starter to the Block Bol..............................................................................................66 lb ft
- Tensioner to Tensioner Bracket Nut.......................................................................... 40 lb ft
- Throttle Body to the Intake Manifold.........................................................................89 lb in
- Thrust Plate to the Balance Shaft Housing.................................................................. 115 lb in
- Timing Chain Housing to the Block Bolts/Studs..........................................................21 lb ft
- Timing Chain Housing to the Camshaft Housings.......................................................19 lb ft
- Timing Chain Tensioner to Housing and Block............................................................89 lb in
- Transaxle To Block Bol................................................................................................43 lb ft
- Transaxle To Block Nut................................................................................................49 lb ft
- Transaxle To Block Stud...............................................................................................115 lb in


GM Supercharger Overview:

A popular option for adding forced induction to the 2.4L LD9 'Twin Cam' engine is the supercharger kit offered by General Motors.

LD9 'Twin Cam' Supercharger (Click to Enlarge) This integral "roots-type" supercharger and manifold design was developed to maximize both engine horsepower and torque without sacrificing durability. Vehicle Control Module (VCM) calibration is a key factor in both performance and driveability. This supercharger has its own unique calibration designed specifically for 2000 to 2002 model year 2.4L Twin Cam engines. Being an integral design gives the supercharger a "clean" factory look and more importantly, it's GM factory engineered. The GM Performance Part kit is the only supercharger that has met GM Engineering standards. The 2.4L Twin Cam Supercharger has undergone more extensive testing and tuning than any other power-adding device. If your goal is to make a reliable 190 HP and add over 40 lb/ft of torque with your 2.4 Twin Cam, this is the only way to go. The end result is a reliable, compact powertrain that has more power than many V6 engines.

The supercharger kit is available under GM part number 12498287. It includes many parts, specifically:
- All mounting brackets and all mounting fasteners required for installation.
- All air ducts and adapters including new PCV hoses, baffle and tubes required for installation.
- Gen II Map Sensor, four spark plugs, accessory drive belt required for installation.
- Recalibration of the Vehicle Control Module (VCM) is also included in the kit.

The supercharger kit, without any additional modifications, brings the stock horsepower up to about 190hp. It was specifically designed for the 2000-2002 Chevrolet Cavalier and Pontiac Sunfire models with the 2.4L LD9 engine and M86/M94 transaxle.

Normal technician's hand tools are all that's required to install this supercharger kit (recalibration of the on-board vehicle control module must be done at an authorized GM dealership). Skilled technicians can easily complete a full installation in a single day.

The 2.4L Twin Cam Supercharger Kit carries a warranty covering the complete kit for defects in material and workmanship for a period of 12 months or 12,000 miles from date of installation. In addition to the product warranty, this supercharger kit will cover the powertrain (internally lubricated engine and transmission components) for the length of the original factory powertrain warranty. For specific details contact your local GM Performance Parts dealer.