The LQ9 is a 6.0L Gen. 3 small block engine used in GM trucks between 2002 and 2007. For marketing purposes, it was also known as the Vortec HO 6000 or VortecMAX. The information listed here is for the stock engine.
Mechanically similar, General Motors’ LS and LS-based Vortec engines wound up on almost every branch of the GM family tree: Chevy, Pontiac, GMC, Cadillac, Buick—heck, even Saab, Hummer, and Isuzu got some LS love.
Since LS and Vortec engines are so common, they’ve become the go-to performance and swap engines of the modern era.
These motors are capable of making a lot of horsepower, and respond well to upgrades like turbos, superchargers, high-flow cylinder heads, intake systems, cams, and nitrous oxide.
The aftermarket is strong, crate engines are available, and used motors are often cheaply sourced through junkyards.
Summit Racing has created a series of comprehensive guides for each engine in the LS family, so engine builders and tuners can have a handy reference for their projects.
This guide is specifically for the GM LQ9 engine.
[Looking to upgrade your LQ9 engine? Check out LQ4/LQ9 Engine Upgrade Guide: Expert Advice for LQ4 & LQ9 Mods to Maximize Performance.]
You can explore all of our LS engine spec guides and LS tech resources here.
(Summit Racing’s Brian Nutter and Paul Spurlock contributed to this article.)
Chevy LQ9 Engine Specs
LQ9 Performance Specifications
| Engine Ratings | |
|---|---|
| Compression Ratio | 10.1:1 |
| Horsepower Rating | 345 hp |
| Torque Rating | 380 ft./lbs. |
LQ9 Applications
| VIN 8th Digit | Year | Make | Model |
|---|---|---|---|
| N | 2002-06 | Cadillac | Escalade |
| N | 2002-06 | Cadillac | Escalade EXT |
| N | 2002-06 | Cadillac | Escalade ESV |
| N | 2003-07 | Chevy | Silverado SS |
| N | 2004-06 | Chevy | Silverado HO Edition |
| N | 2004-06 | GMC | Sierra HO Edition |
| N | 2006-07 | Chevy | Silverado Classic VortecMAX |
| N | 2006-07 | GMC | Sierra 1500 Classic VortecMAX |
LQ9 Engine Blocks
| LQ9 Block Specs | |
|---|---|
| Casting Numbers | 12551364, 12573581, 12577184 |
| Material | Iron |
| Displacement | 6.0L / 364 c.i.d. |
| Bore Dia. | 4.000 in. |
| Stroke | 3.622 in. |
| Deck Height | 9.230 - 9.240 in. |
| Bore Spacing | 4.400 in. |
| Thrust Bearing Location | #3 Main |
| Main Cap Style | 6-Bolt |
| Main Housing Bore Dia. | 2.751 in. |
| Cam Housing Bore Dia. (2002-03) | Bore 1/5 = 2.326, Bore 2/4 = 2.317, Bore 3 = 2.307 |
| Cam Housing Bore Dia. (2003-07) | Bore 1/5 = 2.346, Bore 2/4 = 2.326, Bore 3 = 2.307 |
| Cam-to-Crank Centerline | 4.914 in. |
LQ9 Rotating Assembly
| LQ9 Rotating Assembly Specs | |
|---|---|
| Piston Material | Hypereutectic Cast Aluminum Alloy |
| Piston Style | Flat Top |
| Piston Volume | 0cc |
| Wrist Pin Dia. | 0.9429 in., 0.9431 in. (Full Floating) |
| Connecting Rod Material | Powdered Metal |
| Connecting Rod Style | I-Beam |
| Connecting Rod Length | 6.098 in. |
| Connecting Rod Bolts | M9 x 1 x 43 |
| Crankshaft Material | Cast Iron |
| Crankshaft Main Journal | 2.559 in. |
| Crankshaft Rod Journal | 2.100 in. |
| Reluctor Wheel | 24X |
| Flexplate/Flywheel Mounting Flange | 0.857 in. |
LQ9 Cylinder Heads
| LQ9 Cylinder Head Specs | |
|---|---|
| Casting Numbers | 035, 317 |
| Material | Aluminum |
| Combustion Chamber Volume | 71cc |
| Intake Port Shape | Cathedral |
| Intake Runner Volume | 210cc |
| Exhaust Port Shape | D-Port |
| Exhaust Runner Volume | 75cc |
| Intake Valve Diameter | 2.000 in. |
| Exhaust Valve Diameter | 1.550 in. |
| Cylinder Head Bolt Style | Torque to Yield (TTY) |
| Cylinder Head Bolt Size 2002-03 | (8) M11 x 2 x 155, (2) M11 x 2 x 100, (5) M8 x 1.25 x 45 |
| Cylinder Head Bolt Size 2004-07 | (10) M11 x 2 x 100, (5) M8 x 1.25 x 45 |
LQ9 Cam Specifications
| LQ9 Cam Specs | |
|---|---|
| Part Number | 12561721 |
| Duration @ .050 in. (int./exh.) | 196/201 |
| Valve Lift (int./exh.) | 0.467 in./0.479 in. |
| Lobe Separation Angle | 116° |
| Cam Gear Attachment | 3-Bolt |
LQ9 Valvetrain Specs
| LQ9 Valvetrain Specs | |
|---|---|
| Lifter Style | Hydraulic Roller |
| Lifter Link Style | Plastic Lifter Tray |
| Lifter Body Diameter | 0.842 in. |
| Pushrod Length | 7.385 in. |
| 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 Dia. | 2.000 in. |
| Exhaust Valve Material | Steel - Solid Stem |
| Exhaust Valve Dia. | 1.550 in. |
Other Key LQ9 Specs
| LQ9 Throttle Body, Fuel Injectors, Oil Pan Specs & More | |
|---|---|
| Intake Manifold | Truck Style |
| Throttle Body | 80mm, 3-Bolt |
| Throttle Control | Electronic, Drive-by-Wire |
| Fuel Injector Flow | 25.2 lbs./hr. |
| Fuel Injector Length (between O-Rings) | 1.9 in. |
| Fuel Injector Connector | EV6 |
| PCM | Warren |
| Crankshaft Reluctor Ring | 24x |
| Camshaft Sensor | Rear Mount, 1x on Cam |
| Oil Pan | Deep Rear Sump |
| Oil Pump | Standard Volume |
…
NOTE: You can find engine specs and detailed engine upgrade advice for every LS and LS-based Vortec truck engine in one place: The Definitive Guide to LS Engine Specs and LS Engine Upgrades.
[…] LQ9 Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More […]
Necesito el Diagrama eléctrico del LQ9 6.0 montado en un Isuzu serie N (truck)
I’m putting a 2005 lq9 together, and the wrist pins are discolored. It looks like they got extremely hot? Any input? The bearings, all looked good. And blocked chk”d out good.
The LQ9s had full floating rods so there should have been less friction than the press-fit.
The factories do run pin-to-piston clearance tight, in an effort to reduce noise. They will often have a .0002 in. press fit that opens up under running conditions when the aluminum pin bore expands more than the steel pin.
Check the pin bores and see if there is any sign of metal transfer–this will appear as a tear in an otherwise smooth surface. You can also check the small end rod bushing.
Check for excessive wear–you should be able to slide the pin in when it’s completely square and you should feel *almost* no vertical movement at the ends of the pin when you push them up and down.
The pins being discolored isn’t good and it would be good to replace them.
The diameter on the full floating rod Gen. 4 models is about .9431 inch, which is smaller than the old .9449 in. press fit pins.
were all lq9 engines full floating pistons
Bill
Hi Bill, we have found no evidence that LQ9s ever came with anything other than full floating piston pins. Of note, the LS6 came along in 2001 (one year earlier) and had the same.
Is there any difference between a 2002 LQ9 and a 2006 LQ9? Is a 4l60e or 4l80e better to go behind it? And last how much boost can a stock LQ9 handle? I want to install a turbocharger and don’t want to push it over the edge! Thanks
Hello Marcus,
I have a built 4L60E behind my turbo LQ9 installed in an 08 Tahoe. I have no problems up to 7-8 psi (which is all I’m running for now).
All stock rotating assembly and valvetrain too.
What should I do to get the most hp out of my lq9 I’m going twin turbo would like to know what cam an what turbos an whatever else you recommend I’m putting a swap in my 1974 caprice convertible
Just want to know what I need to get the most out my lq9 with a twin turbo set up
Jarrod, try calling Texas Speed and Performance, or Brian Tooley Racing. Either one of those places should be able to recommend a good cam, heads, and whatever else your budget allows for. Good luck!
I have a 2000 6.0 iron block I have a set of 317 heads was told they came off an Escalade but he wasn’t sure what year I’m looking to get ARP head bolts but not sure which ones . Any suggestions ? Thx
[…] LQ9 Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More […]
I’m swapping my aluminum heads for steel heads. Do I need to up grade my rocker arms, water pump, oil pump or any other component connected to the engine to steel if they’re aluminum?
Why going to steel??
What generation is the lq9 considered? Is it an ls1, ls3? I need some help lol
The LQ9 is a Gen3 LS series engine, as is the LS1.
The LS3 is a Gen4 LS series engine.
You can read this article that explains it all.
https://www.onallcylinders.com/2017/09/21/ls-engines-101-introductory-overview-gen-iiiiv-ls-engine-family/
I put a LQ9 motor in my 57. it thru a O2 sensor check engine lite. i don’t know which sensor to get and help please?
Looking for more of an upgrade for marine application. Boat had 2 260 hp 350 mercruiser. Looking to put LQ9’s to replace. Hoping for 440 hp.plus. anu help would be very helpful. thamks
[…] LQ9 Engine Specs: Performance, Bore & Stroke, Cylinder … […]
Looking for answers. I had an engine swap from an lq4 2005 2500HD to an lq9 out of an 04 Escape. Fuel injection Flow on the lq4 is 24.8lbs and hr. Flow on the lq9 is 25.2 and hr. Dose the ECM need to be reprogrammed
I have a Chevy Silverado 1500 HD with a 6.0l LQ4, and was wondering if the LQ9 is a direct swap?
They’re the same thing. The lq4 has dish pistons that give it a 9.4 compression and lq9 has flat top piston which give it a 10.1 compression. The HP difference is 25 more HP ONLY. Cheaper to just put a cam in it with .575 lift up to .600 lift max for the best bang for your buck. With springs and harden push rods the complete kit runs about $500
Does a 2006 gen 3 lq9 have dod?
No
I hav a 2004 gmc Sierra with a Chevy performance 6.0l 364/450 lq9 engine, with the price of gas can I run regular in it. Also pulling my 4000 lb rv is it ok to run 4500 rpm in 2nd gear up hill at 65 mph to keep traffic from backing up?
my tranny is a 4l60e
only premium or it will knock