The LS3 is a Gen. 4, 6.2L small block engine used in GM performance cars between 2009 and 2017. The engine specs and information listed here is for a stock LS3 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 specific guide is for the GM LS3, you can find more LS engine spec guides and LS-related information here.
[Do you have an LS3 engine you want to upgrade? Read: LS3 Car Engine Upgrade Guide: Expert Advice for LS3 Engine Mods to Maximize Performance.]
(Summit Racing’s Paul Spurlock and Brian Nutter contributed to this article.)
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Chevy LS3 Engine Specs
LS3 Performance Specifications
| Engine Ratings | |
|---|---|
| Compression Ratio | 10.7:1 |
| Horsepower Rating | 426-436 hp |
| Torque Rating | 420-428 ft./lbs. |
LS3 Applications
| VIN 8th Digit | Year | Make | Model |
|---|---|---|---|
| W | 2008-13 | Chevy | Corvette (Base and Z51) |
| W | 2009 | Pontiac | G8 GXP |
| W | 2010-13 | Chevy | Corvette Grand Sport* |
| W | 2010-15 | Chevy | Camaro SS (manual) |
| W | 2014-17 | Chevy | SS |
| N/A** | 2009-15 | Holden | HSV |
| N/A** | 2015-17 | Holden | Commodore VF |
**The Australian vehicles use a different format for Vehicle Identification Numbers (VIN). The 8th digit is NOT the engine code in an Australian VIN code.
LS3 Engine Blocks
| LS3 Block Specs | |
|---|---|
| Block Part Number | 12584724, 12584727 |
| Casting Number | 12621766 |
| Material | 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 |
| 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. |
LS3 Rotating Assembly
| LS3 Rotating Assembly Specs | ||
|---|---|---|
| Engine Version | Wet Sump | Dry Sump |
| Piston Material | Hypereutectic Cast Aluminum Alloy | Hypereutectic Cast Aluminum Alloy |
| Piston Style | Flat Top | Flat Top |
| Piston Volume | 0cc | 0cc |
| Wrist Pin Dia. | 0.9431 in. (full floating) | 0.9431 in. (full floating) |
| Connecting Rod Material | Powdered Metal | Powdered Metal |
| Connecting Rod Style | I-Beam | I-Beam |
| Connecting Rod Length | 6.098 in. | 6.098 in. |
| Connecting Rod Housing Bore | 2.225 in. | 2.225 in. |
| Connecting Rod Bolts | M9 x 1 x 43 | M9 x 1 x 43 |
| Connecting Rod Part Number | 12649190 | 12649190 |
| Crankshaft Material | Cast Iron | Forged Steel |
| Crankshaft Part Number | 12597569 | 12630431 |
| Crankshaft Rear Flange | 6-Bolt | 6-Bolt |
| Crankshaft Main Journal | 2.559 in. | 2.559 in. |
| Crankshaft Rod Journal | 2.100 in. | 2.100 in. |
| Reluctor Wheel | 58x | 58x |
LS3 Cylinder Heads
| LS3 Cylinder Head Specs | |
|---|---|
| Casting Number | 821 |
| Material | Aluminum |
| Combustion Chamber Volume | 68cc |
| Intake Port Shape | Rectangle |
| Intake Runner Volume | 257cc |
| Exhaust Port Shape | D-Port |
| Exhaust Runner Volume | 87cc |
| Intake Valve Diameter | 2.165 in. |
| Exhaust Valve Diameter | 1.590 in. |
| Cylinder Head Bolt Style | Torque to Yield (TTY) |
| Cylinder Head Bolt Size | (10) M11 x 2 x 100, (5) M8 x 1.25 x 45 |
LS3 Cam Specifications
| Engine Version | Wet Sump | Dry Sump |
|---|---|---|
| Duration @ .050 in. (int./exh.) | 204°/211° | 204°/211° |
| Valve Lift (int./exh.) | 0.551 in./.525 in. | 0.551 in./.525 in. |
| Lobe Separation | 117° | 117° |
| Camshaft Part Number | 12623066 | 12631811 |
| Cam Gear Attachment | 1-Bolt | 3-Bolt |
| Cam Gear Poles | 4x | 4x |
| Active Fuel Management (AFM) | No | No |
| Variable Valve Timing (VVT) | No | No |
LS3 Valvetrain
| LS3 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 | Intake Rocker, 6.25mm |
| Valve Spring Style | Beehive |
| Valve Spring Color | Natural |
| Valve Angle | 15 Degrees |
| Intake Valve Material | Steel – Hollow Stem |
| Intake Valve Dia. | 2.165 in. |
| Exhaust Valve Material | Steel – Solid Stem |
| Exhaust Valve Dia. | 1.590 in. |
| Timing Chain Guide Style | Spring Loaded Tensioner |
Other Key LS3 Specs
| Throttle Body, Fuel Injectors, Oil Pan Specs & More | |
|---|---|
| Intake Manifold | Car-Style |
| Throttle Body | 90mm, 4-Bolt, Gold Blade |
| Throttle Control | Electronic, Drive-by-Wire |
| Fuel Injector Part Number | 12576341 |
| Fuel Injector Flow | 42 lbs./hr. at 58 psi |
| Flex Fuel Capable (E-85) | No |
| Fuel Injector Length (between O-Rings) | 1.5 in. |
| Fuel Injector Connector | EV6-USCAR |
| PCM | E38 |
| Crankshaft Reluctor Ring | 58x |
| Camshaft Sensor | Front mount, 4x |
| Oil Pan Sump Location | Varies By Model |
| Oil Pump | Standard Volume (.96 c.i. per rev. @ 33 psi) |
| Oil Pump Part Number | 12678151 (wet sump), 12623097 (dry sump) |
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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.
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I have a 2012 Camaro SS L99 6.2L. I recently had one of the AFM lifters collapse and I am replacing all of the lifters with LS7 type. I am deleting the AFM from the setup but want to maintain VVT. The cam specs you have listed for the L99 & the LS3 have the exact same model # 12623066. If this is the case, I shouldn’t have to replace the cam. The LS3 does not have AFM or VVT, but the L99 has both. But if they are both using the exact same cam I should be fine, correct?
just buy a LS3 snd you want have to worrie about it and you will be much faster in return.
No, it won’t the piston will expand and the engine block will crack
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What cam bearings does the LS3 use. I was looking at the CH-23 set. Just not sure.
Clarification: *Chevrolet Corvette Grand Sport COUPE WITH MANUAL TRANSMISSION received a special version of the LS3 with the dry sump oil system. These engines were built at the Wixom Performance Build Center alongside the LS6 engines for the Z06 and LS9 engines for the ZR1. Each of these engines were assembled by hand by mechanics qualified for performance engine builds. These engines have a plaque affixed that identify the professional who assembled the engine.
[…] LS3 Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More […]
I was just looking for LS3 Engine Specs. great
How to confirm that I have a ls3 engine in my 2011 grand sport Corvette? Is there any markings I can see on the engine in the car?
Hey Larry, yes–the 8th digit of the VIN will have a “W” and you can find the VIN etched on the engine block’s (driver) side, near the oil filter.
What’s the # of camshaft splines on a new LS3 crate engine? 26? 376/525 hp 6.2L
32 actually
this will fit a 3rd gen trans am, everyone agree??
Plenty of folks have LS-swapped third-gen. F-bodies. Summit Racing has a handy LS Swap Guide here, but you might want to contact the Summit Racing tech folks, because there are some other things to consider (like oil pan clearance and ecu/engine management) and they can help you build a comprehensive list of what you’ll need.