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
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
Is the 5.3 L Vortec a Good Engine?
LQ9 Engine Specs
Let’s take a look at the more detailed LQ9 specs based on the following categories:
- Performance Specifications
- Application Information
- Engine Block Specifications
- Cylinder Head Specifications
- Valvetrain Specifications
- Rotating Assembly Specifications
- Camshaft Specifications
- 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 Ratio | 10.1:1 |
| Horsepower (hp) Rating | 345 hp |
| Torque Rating | 380 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 Digit | N |
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
| Year | Make | Model |
| 2002 – 2006 | Cadillac | Escalade |
| Cadillac | Escalade EXT | |
| Cadillac | Escalade ESV | |
| 2003 – 2007 | Chevrolet | Silverado SS |
| 2004 – 2006 | Chevrolet | Silverado HO Edition |
| GMC | Sierra HO Edition | |
| 2006 – 2007 | Chevrolet | Silverado Classic Vortec Max |
| GMC | Sierra 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 Numbers | 12551364, 12573581, 12577184 |
| Material | Iron |
| Displacement | 6.0L / 364 cid |
| Bore Diameter | 4.000 inches |
| Stroke | 3.622 inches |
| Deck Height | 9.230 – 9.240 inches |
| Bore Spacing | 4.400 inches |
| Thrust Bearing Location | #3 Main |
| Main Cap Style | 6 Bolts |
| Main Housing Bore Diameter | 2.751 inches |
| Cam Housing Bore Diameter | 1/5 = 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 Centerline | 4.914 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
| Years | 2002 – 2007 |
| Casting Numbers | 035, 317 |
| Combustion Chamber Volume | 71 cc |
| Material | Aluminum |
| Intake Port Shape | Cathedral |
| Intake Runner Volume | 210 cc |
| Exhaust Port Shape | D Port |
| Exhaust Runner Volume | 75 cc |
| Intake Valve Diameter | 2.000 inches |
| Exhaust Valve Diameter | 1.550 inches |
| Cylinder Head Bolt Style | Torque 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
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 Style | Hydraulic Roller |
| Lifter Link Style | Plastic Lifter Tray |
| Lifter Body Diameter | 0.842 inches |
| Pushrod Length | 7.385 inches |
| Rocker Arm Mounting Style | Pedestal |
| Rocker Arm Style | Die-Cast, Roller Fulcrum |
| Rocker Ratio | 1.7 |
| Rocker Offset | None |
| Valve Spring Style | Beehive |
| Valve Spring Color | Natural |
| Valve Angle | 15 Degrees |
| Intake Valve Material | Steel – Solid Stem |
| Intake Valve Diameter | 2.000 inches |
| Exhaust Valve Material | Steel – Solid Stem |
| Exhaust Valve Diameter | 1.550 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 Material | Hypereutectic Cast Aluminum Alloy |
| Piston Style | Flat Top |
| Piston Volume | 0 cc |
| Wrist Pin Dia. (2002-07) | 0.9429 inches, 0.9431 inches (Full Floating) |
| Connecting Rod Material | Powdered Metal |
| Connecting Rod Style | I-Beam |
| Connecting Rod Length | 6.098 inches |
| Connecting Rod Bolts | M9 x 1 x 43 |
| Crankshaft Material | Cast Iron |
| Crankshaft Main Journal | 2.559 inches |
| Crankshaft Rod Journal | 2.100 inches |
| Reluctor Wheel | 24x |
| Flexplate/Flywheel Mounting Flange | 0.857 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
| Years | 2002 – 2007 |
| Part Number | 12561721 |
| 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 Attachment | 3 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 Body | 80 mm, 3-Bolt |
| Throttle Control | Electronic (Drive-by-Wire) |
| Intake Manifold | Truck Style |
| Fuel Injector Flow | 25.2 lbs |
| Fuel Injector Connector | EV6 |
| Fuel Injector Length (between O-Rings) | 1.9 inches |
| Camshaft Sensor | Rear Mount, 1x on cam |
| Crankshaft Reluctor Ring | 24x |
| Oil Pan | Deep Rear Sump |
| Oil Pump | Standard Volume |
| PCM | Warren |
Summary of the LQ9 Engine Specs
| Application Information | |
| VIN 8th Digit | N |
| Year | Make / Model |
| 2002 – 2006 | Cadillac Escalade |
| Cadillac Escalade EXT | |
| Cadillac Escalade ESV | |
| 2003 – 2007 | Chevrolet Silverado SS |
| 2004 – 2006 | Chevrolet Silverado HO Edition |
| GMC Sierra HO Edition | |
| 2006 – 2007 | Chevrolet Silverado Classic Vortec Max |
| GMC Sierra Classic Vortec Max | |
| Engine Block Specifications | |
| Casting Numbers | 12551364, 12573581, 12577184 |
| Material | Iron |
| Displacement | 6.0L / 364 cid |
| Bore Diameter | 4.000 inches |
| Stroke | 3.622 inches |
| Deck Height | 9.230 – 9.240 inches |
| Bore Spacing | 4.400 inches |
| Thrust Bearing Location | #3 Main |
| Main Cap Style | 6 Bolts |
| Main Housing Bore Diameter | 2.751 inches |
| Cam Housing Bore Diameter | 1/5 = 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 Centerline | 4.914 inches |
| Rotating Assembly Specifications | |
| Piston Material | Hypereutectic Cast Aluminum Alloy |
| Piston Style | Flat Top |
| Piston Volume | 0 cc |
| Wrist Pin Dia. (2002-07) | 0.9429 inches, 0.9431 inches (Full Floating) |
| Connecting Rod Material | Powdered Metal |
| Connecting Rod Style | I-Beam |
| Connecting Rod Length | 6.098 inches |
| Connecting Rod Bolts | M9 x 1 x 43 |
| Crankshaft Material | Cast Iron |
| Crankshaft Main Journal | 2.559 inches |
| Crankshaft Rod Journal | 2.100 inches |
| Reluctor Wheel | 24x |
| Flexplate/Flywheel Mounting Flange | 0.857 inches |
| Cylinder Head Specifications | |
| Years | 2002 – 2007 |
| Casting Numbers | 035, 317 |
| Combustion Chamber Volume | 71 cc |
| Material | Aluminum |
| Intake Port Shape | Cathedral |
| Intake Runner Volume | 210 cc |
| Exhaust Port Shape | D Port |
| Exhaust Runner Volume | 75 cc |
| Intake Valve Diameter | 2.000 inches |
| Exhaust Valve Diameter | 1.550 inches |
| Cylinder Head Bolt Style | Torque 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 Style | Hydraulic Roller |
| Lifter Link Style | Plastic Lifter Tray |
| Lifter Body Diameter | 0.842 inches |
| Pushrod Length | 7.385 inches |
| Rocker Arm Mounting Style | Pedestal |
| Rocker Arm Style | Die-Cast, Roller Fulcrum |
| Rocker Ratio | 1.7 |
| Rocker Offset | None |
| Valve Spring Style | Beehive |
| Valve Spring Color | Natural |
| Valve Angle | 15 Degrees |
| Intake Valve Material | Steel – Solid Stem |
| Intake Valve Diameter | 2.000 inches |
| Exhaust Valve Material | Steel – Solid Stem |
| Exhaust Valve Diameter | 1.550 inches |
| Camshaft Specifications | |
| Years | 2002 – 2007 |
| Part Number | 12561721 |
| 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 Attachment | 3 Bolts |
| Other Specifications | |
| Throttle Body | 80mm, 3-Bolt |
| Throttle Control | Electronic (Drive-by-Wire) |
| Intake Manifold | Truck Style |
| Fuel Injector Flow | 25.2 lbs |
| Fuel Injector Connector | EV6 |
| Fuel Injector Length (between O-Rings) | 1.9 inches |
| Camshaft Sensor | Rear Mount, 1x on cam |
| Crankshaft Reluctor Ring | 24x |
| Oil Pan | Deep Rear Sump |
| Oil Pump | Standard Volume |
| PCM | Warren |
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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