The LS9 is a Gen. 4, 6.2L, aluminum small block engine used in GM cars between 2009 and 2013. The information listed here is for a stock LS9 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.
[NOTE: Looking to upgrade your LS9? Read: LS9 6.2L Engine Upgrade Guide: Expert Advice for LS9 Mods to Maximize Performance.]
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 specific guide is for the GM LS9 6.2L engine.
You can find more LS engine spec guides and LS-related information here.
(Summit Racing’s Paul Spurlock and Brian Nutter contributed to this article.)
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LS9 6.2L Engine Specs
LS9 Performance Specifications
| Engine Ratings | |
|---|---|
| Compression Ratio | 9.1:1 |
| Horsepower Rating | 638 hp @ 6,300 rpm |
| Torque Rating | 604 ft./lbs. |
LS9 Engine Blocks
| LS9 Engine Block Specs | |
|---|---|
| Casting Numbers | 12621766 |
| Material | 319-T7 Aluminum |
| Displacement | 6.2L / 376 c.i.d. |
| Bore Dia. | 4.065 in. |
| Stroke | 3.622 in. |
| Deck Height | 9.240 in. |
| Bore Spacing | 4.400 in. |
| Thrust Bearing Location | #3 Main |
| Main Cap Style | 6-Bolt, Billet Steel |
| Main Housing Bore Dia. | 2.751 in. |
| Cam Housing Bore Dia. | Bore 1/5 = 2.346, Bore 2/4 = 2.326, Bore 3 = 2.307 |
| Cam-to-Crank Centerline | 4.914 in. |
| Head Bolts | M12 |
LS9 Rotating Assembly
| LS9 Rotating Assembly Specs | |
|---|---|
| Piston Material | Hypereutectic Cast Aluminum Alloy |
| Piston Part Number | 19180414 |
| Piston Style | Dished; No Relief Valves |
| Piston Volume | +15cc |
| Wrist Pin Dia. | 0.984 in. |
| Connecting Rod Part Number | 12624231 |
| Connecting Rod Material | Titanium, Moly-Coated |
| Connecting Rod Weight | 452-482g |
| Connecting Rod Style | I-Beam |
| Connecting Rod Length | 5.990 in. |
| Connecting Rod Housing Bore | 2.225 in. |
| Connecting Rod Bolts | M9 x 1 x 40 |
| Crankshaft Material | Forged Steel, 46MnVS |
| Crankshaft Part Number | 12598610 (2009-11), 12641693 (2011-15) |
| Crankshaft Rear Flange | 9-Bolt |
| Crankshaft Snout | Long, with keyway |
| Crankshaft Main Journal | 2.559 in. |
| Crankshaft Rod Journal | 2.100 in. |
| Reluctor Wheel | 58x |
LS9 Cylinder Heads
| LS9 Cylinder Head Specs | |
|---|---|
| Cylinder Head Part Number | 12621773 |
| Casting Numbers | 1771 |
| Material | 356-T6 Rotocast Aluminum |
| Combustion Chamber Volume | 69.8cc |
| Intake Port Shape | Rectangle |
| Intake Runner Volume | 259cc |
| Exhaust Port Shape | D-Port |
| Exhaust Runner Volume | 89cc |
| Valve Seat Material (int./ext.) | PMF28 / Brico 3220 |
| Cylinder Head Bolt Style | Torque to Yield (TTY) |
| Cylinder Head Bolt Size | (10) M12 x 2 x 100, (5) M8 x 1.25 x 45 |
| Head Gasket Part Number | 12622033 |
| Head Gasket Compressed Thickness | 0.055 in. |
LS9 Camshaft Specifications
| LS9 Camshaft Specifications | |
|---|---|
| Camshaft Part Number | 126384277 |
| Duration @ .050 in. (int./exh.) | 211°/230° |
| Valve Lift (int./exh.) | 0.562 in./0.558 in. |
| Lobe Separation | 122.5° |
| Cam Gear Attachment | 3-Bolt |
| Cam Gear Poles | 4x |
| Active Fuel Management (AFM) | No |
| Variable Valve Timing (VVT) | No |
LS9 Valvetrain
| LS9 Valvetrain Specs | |
|---|---|
| Lifter Style | Hydraulic Roller |
| Lifter Link Style | Plastic Lifter Tray |
| Lifter Body Diameter | 0.842 in. |
| Pushrod Length | 7.385 in. |
| Pushrod Diameter | 0.3125 in. |
| Rocker Arm Mounting Style | Pedestal |
| Rocker Arm Style | Die-Cast, Roller Fulcrum |
| Rocker Ratio | 1.7 |
| Rocker Offset | Intake only |
| Valve Spring Style | Beehive |
| Valve Spring Seat Pressure | 90 lbs. @ 1.800 in. |
| Valve Spring Spring Open Pressure | 295 lbs. @ 1.250 in. |
| Valve Spring Color | Natural |
| Valve Angle | 15 Degrees |
| Intake Valve Material | Titanium, with Chrome Nitride |
| Intake Valve Dia. | 2.165 in. |
| Exhaust Valve Material | Stainless steel, Sodium Filled |
| Exhaust Valve Dia. | 1.590 in. |
| Timing Chain Part Number | 12646386 |
| Timing Chain Guide Style | Wedge Shaped Plastic Dampener |
LS9 Supercharger Specifications
| Supercharger Part Number | 19244103 (solid coupler) R2300 |
|---|---|
| Displacement | 2.3L |
| Supercharger Drive | 2.32 drive ratio, 15,080 rpm, 9.4 lbs. boost |
| Rotor Dimensions | 4.400 diameter, 8.300 length, 160 degree |
| Pulley Diameter | 3.100 in. upper / 7.330 in. lower |
Other Key LS9 Specs
| Throttle Body, Fuel Injectors, Oil Pan Specs & More | |
|---|---|
| Intake Manifold | Cast Aluminum, with integrated intercooler |
| Throttle Body | 87mm |
| Throttle Control | Electronic (Drive-by-Wire) |
| ECM | E-67 |
| Fuel Injector Part Number | 12598646 |
| Fuel Injector Flow | 59 lb./hr. @ 58 psi |
| Flex Fuel Capable (E-85) | No |
| Fuel Injector Length (between O-Rings) | 1.500 in. |
| Fuel Injector Connector | EV6-USCAR |
| Camshaft Sensor Location | Timing Cover |
| Oiling System | Dry Sump |
| Oil Pan | Center Sump (with a bolt-on cooler) |
| Oil Pump Part Number | 12578147 |
| Oil Pump Volume | 32.3 gpm |
| Engine Weight (with Manifolds, supercharger, Clutch, Flywheel, Balancer, Waterpump | 531 lbs. |
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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.
[…] [Every engine spec you’ll need can be found here: LS9 Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More.] […]
[…] LS9 Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More […]
We would like to consider the adaption of the LS9 engine for use on aircraft. We designed the 500 CID, 750 HP Thunder engine, Installed on aircraft and certified with the FAA. To test for survivability and part failure we ran the engine at max power (750 @ 5300 RPM) for 823 hours before the failure of the quill shaft due to lack of cooling oil, is easy fix. We have gear reduction housings that fit the LS9 block. It’s a $30M+ a year market.
Is there any interest in pursuing is market?
[…] Yep, it wasn’t until 2012 that the alphanumeric combo of Z, R, and 1 first appeared on a Corvette pace car. Boasting north of 630 horsepower, it was the most powerful production pace car at the time. Under its hood was a supercharged 6.2-liter LS9 engine. […]
Dude, you forgot Australia’s legendary muscle car that used this engine… the 2017 HSV GTSR W1. Gosh, I miss our car industry.
Excellent if you want to drop the hammer when needed for the sound and performance