LQ9 Engine Specs and Review

Are you planning to buy a Cadillac Escalade or a pickup truck from General Motors? If yes, then the chances are that the vehicle is equipped with the LQ9 engine. Or, maybe, you are thinking of getting the LQ9 engine for your vehicle and wondering if it is a good match. In this LQ9 engine review, I’ll list its features and specs so you can decide if it is the right car engine for you.

The LQ9 engine was introduced in 2002 as an improved and higher output version of the LQ4 engine. It was initially launched for the Cadillac Escalade and later on, was used in other General Motors pickup trucks. The LQ9 is a 6.0L Third Generation small block engine originally marketed either as VortecMAX or Vortec HO 6000.

Read on to learn more about the LQ9 engine, including its specs and features.

About the LQ9 Engine

LQ9 Engine

Improved and Higher Output Version of the LQ4 Engine

The LQ9 engine was launched in 2002 as an improved and higher output version of the LQ4 engine. It was initially produced for the Cadillac Escalade and later on, was used in other General Motors pickup trucks.

6.0L Third Generation Small Block Engine

The LQ9 is a 6.0L Third Generation small block engine originally marketed either as VortecMAX or Vortec HO 6000.

Features High Compression Flat Top Piston

LQ9 engines only had one manufacturing plant in Romulus, Michigan. It featured high compression flat top pistons to deliver an added 20 horsepower (hp) and ten lb-ft of torque.

This translates to 15 kW and 14 Nm, providing 345 hp or 257 kW power output. That is about 380 lb-ft of torque or 515 Nm. 

Produced Between 2002 and 2007

The LQ9 type of engine was only produced between 2002 and 2007. So, if you’re interested in a used Cadillac, Chevrolet, or GMC vehicle, you might find a unit equipped with this engine.

Vehicles Equipped with LQ9 Engine

Some of the vehicles that have the LQ9 engine are the following:

  • 2002 – 2006 Cadillac Escalade AWD
  • 2006 Cadillac Escalade 2WD
  • 2002 – 2006 Cadillac Escalade EXT
  • 2003 – 2006 Cadillac Escalade ESV
  • 2003 – 2007 Chevrolet Silverado SS
  • 2004 – 2006 Chevrolet Silverado
  • 2004 – 2006 GMC Sierra Vortec HO Edition
  • 2004 – 2006 Chevrolet Silverado Performance Edition
  • 2004 – 2006 GMC Sierra Performance Edition
  • 2005 – 2006 GMC Sierra Denali pickup
  • 2005 – 2006 GMC Yukon Denali
  • 2007 Classic Chevrolet Silverado
  • 2007 GMC Sierra VortecMAX
  • 2007 Chevrolet Silverado Performance Edition
  • 2007 GMC Sierra Performance Edition

LQ9 Engine Specs

Let’s take a look at the more detailed LQ9 specs based on the following categories:

  1. Performance Specifications
  2. Application Information
  3. Engine Block Specifications
  4. Cylinder Head Specifications
  5. Valvetrain Specifications
  6. Rotating Assembly Specifications
  7. Camshaft Specifications
  8. Other Specifications

1. Performance Specifications

The LQ9 engine forms part of the third generation of the LS family. It is a 6.0L iron-block truck engine. For its performance specifications, its compression ratio is 10.1:1. The LQ9 horsepower rating is 345 hp, and the torque rating is 380 ft/lb.

LQ9 Engine Performance Specifications

Compression Ratio10.1:1
Horsepower (hp) Rating345 hp
Torque Rating380 ft / lb

2. Application Information

You would know if a vehicle features an LQ9 engine by checking its Vehicle Identification Number (VIN). If the VIN’s 8th character is “N,” then the engine is undoubtedly an LQ9 engine.

LQ9 Engine VIN Information

VIN 8th DigitN

The Cadillac Escalade, EXT, and the ESV manufactured between 2002 and 2006 have LQ9 engines. As for the Chevrolet Silverado SS manufactured between 2003 and 2007, they also all have LQ9 engines.

Between 2004 and 2006, the Chevrolet Silverado HO Edition and the GMC Sierra HO Edition manufactured were equipped with LQ9 engines. So did the Chevrolet Silverado Classic Vortec Max and the GMC Sierra Classic Vortec Max manufactured between 2006 and 2007.

LQ9 Engine Application Information

YearMakeModel
2002 – 2006CadillacEscalade
CadillacEscalade EXT
CadillacEscalade ESV
2003 – 2007ChevroletSilverado SS
2004 – 2006ChevroletSilverado HO Edition
GMCSierra HO Edition
2006 – 2007ChevroletSilverado Classic Vortec Max
GMCSierra Classic Vortec Max

3. Engine Block Specifications

Casting Numbers

The casting numbers for the LQ9 engine, which is made of iron, include 12551364, 12573581, and 12577184. Its displacement is 6.0 liters/364 cid.

Bore Diameter

The bore diameter measures 4.000 inches, while the stroke measures 3.622 inches. Its deck height measures 9.230 – 9.240 inches, while the bore spacing measures 4.400 inches. The thrust bearing location is #3 Main, and its main cap style is six bolts.

Main Housing Bore Diameter

Its main housing bore diameter measures 2.751 inches. As for the cam housing bore diameter of vehicles manufactured between 2002 and 2003, the bore 1/5 equals 2.326, bore 2/4 equals 2.317, while bore 3 equals 2.307.

When it comes to cars produced between 2003 and 2007, the bore 1/5 equals 2.346, bore 2/4 equals 2.326, and bore 3 equals 2.307. In terms of the cam-to-crank centerline, the measurement is 4.914 inches.

LQ9 Engine Block Specifications

Casting Numbers12551364, 12573581, 12577184
MaterialIron
Displacement6.0L / 364 cid
Bore Diameter4.000 inches
Stroke3.622 inches
Deck Height9.230 – 9.240 inches
Bore Spacing4.400 inches
Thrust Bearing Location#3 Main
Main Cap Style6 Bolts
Main Housing Bore Diameter2.751 inches
Cam Housing Bore Diameter1/5 = 2.326
2/4 = 2.317
3 = 2.307 (2002-03 1st design)
1/5 = 2.346
2/4 = 2.326
3 = 2.307 (2003- 07 2nd design)
Cam-to-Crank Centerline4.914 inches

4. Cylinder Head Specifications

Casting Numbers

The casting numbers for the cylinder head are 035 and 317, whereas the combustion chamber volume is 71 cc. This engine’s cylinder head is aluminum and has a cathedral intake port shape.

The intake runner volume is 210 cc, while the exhaust runner volume is 75 cc. As for the shape of the exhaust port, it is a D port. The intake valve diameter measures 2.000 inches, while the exhaust valve diameter measures 1.550 inches.

Bolt Size for Engines Manufactured Between 2002 and 2003

Let’s now move to the cylinder head bolt style, Torque to Yield (TTY). The bolt size for engines manufactured between 2002 and 2003 have the following details:

  • (8) M11 x 2 x 155
  • (2) M11 x 2 x 100
  • (5) M8 x 1.25 x 45

Cylinder Bolt Size for Engines Produced Between 2004 and 2007

Whereas the cylinder bolt size for engines produced between 2004 and 2007 has the following details:

  • (10) M11 x 2 x 100
  • (5) M8 x 1.25 x 45

LQ9 Engine Cylinder Head Specifications

Years2002 – 2007
Casting Numbers035, 317
Combustion Chamber Volume71 cc
MaterialAluminum
Intake Port ShapeCathedral
Intake Runner Volume210 cc
Exhaust Port ShapeD Port
Exhaust Runner Volume75 cc
Intake Valve Diameter2.000 inches
Exhaust Valve Diameter1.550 inches
Cylinder Head Bolt StyleTorque to Yield (TTY)
Cylinder Head Bolt Size (2002- 2003)(8) M11 x 2 x 155, (2) M11 x 2 x 100, (5) M8 x 1.25 x 45
Cylinder Head Bolt Size (2004 – 2007)(10) M11 x 2 x 100, (5) M8 x 1.25 x 45

5. Valvetrain Specifications

lq9 engine specs

Lifter

For the Valvetrain specifications, let’s start with the lifter. Lifter body diameter measures 0.842 inches, the lifter link style is a plastic lifter tray, and the lifter style is a hydraulic roller. As for the pushrod length, it measures 7.385 inches.

Rocker

When it comes to the rocker, the rocker arm mounting style is a pedestal, and the rocker arm style is a die-cast roller fulcrum. There is no rocker offset, while the rocker ratio is 1.7.

Valve

In terms of the valve, the valve angle is 15 degrees. It has a natural valve spring color and beehive valve spring style. The intake valve material is steel – solid stem and measures 2.000 inches.

As for the exhaust valve, the material is steel – solid stem, while the exhaust valve diameter measures 1.550 inches.

LQ9 Engine Valvetrain Specifications

Lifter StyleHydraulic Roller
Lifter Link StylePlastic Lifter Tray
Lifter Body Diameter0.842 inches
Pushrod Length7.385 inches
Rocker Arm Mounting StylePedestal
Rocker Arm StyleDie-Cast, Roller Fulcrum
Rocker Ratio1.7
Rocker OffsetNone
Valve Spring StyleBeehive
Valve Spring ColorNatural
Valve Angle15 Degrees
Intake Valve MaterialSteel – Solid Stem
Intake Valve Diameter2.000 inches
Exhaust Valve MaterialSteel – Solid Stem
Exhaust Valve Diameter1.550 inches

6. Rotating Assembly Specifications

Piston

Let’s talk about the piston of the LQ9 engine. It is made of hyper eutectic cast aluminum alloy, has a flat top piston style, and has a 0cc piston volume.

Wrist Pin Diameter

As for the wrist pin diameter, it measures 0.9429 inches and 0.9431 inches, fully floating.

Connecting Rod

The connecting rod’s material is powdered metal with an I-beam connecting rod style. Its length measures 3.098 inches, while its rod bolts measure M9 x 1 x 43.

Crankshaft

For the crankshaft, the material used is cast iron. The crankshaft’s main journal measures 2.559 inches, while the crankshaft rod journal measures 2.100 inches. The reluctor wheel is 24x, while the flexplate/flywheel mounting flange measures 0.857 inches.

LQ9 Engine Rotating Assembly Specifications

Piston MaterialHypereutectic Cast Aluminum Alloy
Piston StyleFlat Top
Piston Volume0 cc
Wrist Pin Dia. (2002-07)0.9429 inches, 0.9431 inches (Full Floating)
Connecting Rod MaterialPowdered Metal
Connecting Rod StyleI-Beam
Connecting Rod Length6.098 inches
Connecting Rod BoltsM9 x 1 x 43
Crankshaft MaterialCast Iron
Crankshaft Main Journal2.559 inches
Crankshaft Rod Journal2.100 inches
Reluctor Wheel24x
Flexplate/Flywheel Mounting Flange0.857 inches

Again, what is an LQ9 engine? GM trucks (2002 to 2007) are equipped with the LQ9 engine, a 6.0L Gen. 3 small block engine. LQ9 engine is also famous as the Vortec HO 6000 or VortecMAX.

7. Camshaft Specifications

The camshaft manufactured between 2002 and 2007 has part number 12561721. Its duration at .050 in is 196 / 201 for intake and exhaust, respectively. The intake and exhaust valve lift measurements are 0.467 inches / 0.479 inches.

The lobe separation angle is 116 degrees, and the cam gear attachment is three bolts.

LQ9 Engine Camshaft Specifications

Years2002 – 2007
Part Number12561721
Duration at .050 in (int./exh)196 / 201
Valve Lift (int./exh)0.467 inches / 0.479 inches
Lobe Separation Angle (in degrees)116
Cam Gear Attachment3 Bolts

8. Other Specifications

Let’s now talk about all the other specifications worth noting.

Throttle System

When it comes to the throttle system, the throttle body features three bolts and measures 80 mm. It also has electronic Drive-by-Wire control. The intake manifold has a truck style.

Fuel Injector Flow

In terms of the fuel injector flow, it weighs 25.2 lbs. It has an EV6 fuel injector connector, and its length between O rings is 1.9 inches.

Camshaft Sensor

The camshaft sensor is rear-mounted and 1 x on cam, whereas the crankshaft reluctor ring is 24 x. The oil pan is a deep rear sump, while the pump has a standard volume. Lastly, the PCM is Warren.

LQ9 Engine Specifications (Other)

Throttle Body80 mm, 3-Bolt
Throttle ControlElectronic (Drive-by-Wire)
Intake ManifoldTruck Style
Fuel Injector Flow25.2 lbs
Fuel Injector ConnectorEV6
Fuel Injector Length (between O-Rings)1.9 inches
Camshaft SensorRear Mount, 1x on cam
Crankshaft Reluctor Ring24x
Oil PanDeep Rear Sump
Oil PumpStandard Volume
PCMWarren

Summary of the LQ9 Engine Specs

lq9 engine horsepower
Application Information
VIN 8th DigitN
YearMake / Model
2002 – 2006Cadillac Escalade
Cadillac Escalade EXT
Cadillac Escalade ESV
2003 – 2007Chevrolet Silverado SS
2004 – 2006Chevrolet Silverado HO Edition
GMC Sierra HO Edition
2006 – 2007Chevrolet Silverado Classic Vortec Max
GMC Sierra Classic Vortec Max
Engine Block Specifications
Casting Numbers12551364, 12573581, 12577184
MaterialIron
Displacement6.0L / 364 cid
Bore Diameter4.000 inches
Stroke3.622 inches
Deck Height9.230 – 9.240 inches
Bore Spacing4.400 inches
Thrust Bearing Location#3 Main
Main Cap Style6 Bolts
Main Housing Bore Diameter2.751 inches
Cam Housing Bore Diameter1/5 = 2.326
2/4 = 2.317
3 = 2.307 (2002-03 1st design)
1/5 = 2.346
2/4 = 2.326
3 = 2.307 (2003- 07 2nd design)
Cam-to-Crank Centerline4.914 inches
Rotating Assembly Specifications
Piston MaterialHypereutectic Cast Aluminum Alloy
Piston StyleFlat Top
Piston Volume0 cc
Wrist Pin Dia. (2002-07)0.9429 inches, 0.9431 inches (Full Floating)
Connecting Rod MaterialPowdered Metal
Connecting Rod StyleI-Beam
Connecting Rod Length6.098 inches
Connecting Rod BoltsM9 x 1 x 43
Crankshaft MaterialCast Iron
Crankshaft Main Journal2.559 inches
Crankshaft Rod Journal2.100 inches
Reluctor Wheel24x
Flexplate/Flywheel Mounting Flange0.857 inches
Cylinder Head Specifications
Years2002 – 2007
Casting Numbers035, 317
Combustion Chamber Volume71 cc
MaterialAluminum
Intake Port ShapeCathedral
Intake Runner Volume210 cc
Exhaust Port ShapeD Port
Exhaust Runner Volume75 cc
Intake Valve Diameter2.000 inches
Exhaust Valve Diameter1.550 inches
Cylinder Head Bolt StyleTorque to Yield (TTY)
Cylinder Head Bolt Size (2002- 2003)(8) M11 x 2 x 155, (2) M11 x 2 x 100, (5) M8 x 1.25 x 45
Cylinder Head Bolt Size (2004 – 2007)(10) M11 x 2 x 100, (5) M8 x 1.25 x 45
Valvetrain Specifications
Lifter StyleHydraulic Roller
Lifter Link StylePlastic Lifter Tray
Lifter Body Diameter0.842 inches
Pushrod Length7.385 inches
Rocker Arm Mounting StylePedestal
Rocker Arm StyleDie-Cast, Roller Fulcrum
Rocker Ratio1.7
Rocker OffsetNone
Valve Spring StyleBeehive
Valve Spring ColorNatural
Valve Angle15 Degrees
Intake Valve MaterialSteel – Solid Stem
Intake Valve Diameter2.000 inches
Exhaust Valve MaterialSteel – Solid Stem
Exhaust Valve Diameter1.550 inches
Camshaft Specifications
Years2002 – 2007
Part Number12561721
Duration at .050 in (int./exh)196/201
Valve Lift (int./exh)0.467 inches/0.479 inches
Lobe Separation Angle (in degrees)116
Cam Gear Attachment3 Bolts
Other Specifications
Throttle Body80mm, 3-Bolt
Throttle ControlElectronic (Drive-by-Wire)
Intake ManifoldTruck Style
Fuel Injector Flow25.2 lbs
Fuel Injector ConnectorEV6
Fuel Injector Length (between O-Rings)1.9 inches
Camshaft SensorRear Mount, 1x on cam
Crankshaft Reluctor Ring24x
Oil PanDeep Rear Sump
Oil PumpStandard Volume
PCMWarren
Summary of LQ9 Engine Specifications

Frequently Asked Questions – Is the LQ9 Engine Good?

Several frequently asked questions about the LQ9 engine, including its specs and features:

LQ9 vs. LQ4 – Are They the Same?

The only difference between the LQ9 and the LQ4 engines is the piston. In terms of the LQ4 engine, its piston is dished, while the LQ9 engine has a flat top piston. This then increases compression to a ratio of 10:1, as well as the HP to 345.

The LQ9 is an engine with limited production. It is highly desirable since it is a HO 6.0L engine with a premium price.

Is the LQ9 Aluminum?

All LQ9 engines feature aluminum heads, while LQ4 engines have iron heads.

In Closing: Is the LQ9 Engine a Good Engine

To sum it up, the LQ9 engine was launched in 2002 as an improved and higher output version of the LQ4 engine. It was initially produced for the Cadillac Escalade and later on, was used in other General Motors pickup trucks.

The LQ9 is a 6.0L Third Generation small block engine originally marketed either as VortecMAX or Vortec HO 6000.

It was subject to limited production and came with a premium price. Up until now, it has been offered at a premium price. The LQ9 is recognized as a highly desirable engine.

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