LS Engines

LS3 Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More

 
2009 Pontiac G8 LS3 Engine

(Image/Car and Driver)

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.)

Chevy LS3 Engine Specs

The LS3 is a Gen. 4, 6.2L small block engine used in GM performance cars between 2009 and 2017. The information listed here is for a stock engine.

 

LS3 Performance Specifications

Engine Ratings
Compression Ratio10.7:1
Horsepower Rating426-436 hp
Torque Rating420-428 ft./lbs.

LS3 Applications

VIN 8th DigitYearMakeModel
W2008-13ChevyCorvette (Base and Z51)
W2009PontiacG8 GXP
W2010-13ChevyCorvette Grand Sport*
W2010-15ChevyCamaro SS (manual)
W2014-17ChevySS
N/A**2009-15HoldenHSV
N/A**2015-17HoldenCommodore VF
*The Corvette Grand Sport used a special version of the LS3. It had a dry sump oiling system and a modified crankshaft.
**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 Number12584724, 12584727
Casting Number12621766
MaterialAluminum
Displacement6.2L / 376 c.i.d.
Bore Dia. 4.065 in.
Stroke3.622 in.
Deck Height9.240 in.
Bore Spacing4.400 in.
Thrust Bearing Location#3 Main
Main Cap Style6-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 Centerline4.914 in.

LS3 Rotating Assembly

LS3 Rotating Assembly Specs
Engine VersionWet SumpDry Sump
Piston MaterialHypereutectic Cast Aluminum Alloy Hypereutectic Cast Aluminum Alloy
Piston StyleFlat TopFlat Top
Piston Volume0cc0cc
Wrist Pin Dia.0.9431 in. (full floating)0.9431 in. (full floating)
Connecting Rod MaterialPowdered MetalPowdered Metal
Connecting Rod StyleI-BeamI-Beam
Connecting Rod Length6.098 in.6.098 in.
Connecting Rod Housing Bore2.225 in.2.225 in.
Connecting Rod BoltsM9 x 1 x 43M9 x 1 x 43
Connecting Rod Part Number1264919012649190
Crankshaft MaterialCast IronForged Steel
Crankshaft Part Number1259756912630431
Crankshaft Rear Flange6-Bolt6-Bolt
Crankshaft Main Journal2.559 in.2.559 in.
Crankshaft Rod Journal2.100 in.2.100 in.
Reluctor Wheel58x58x

LS3 Cylinder Heads

LS3 Cylinder Head Specs
Casting Number821
MaterialAluminum
Combustion Chamber Volume70cc
Intake Port ShapeRectangle
Intake Runner Volume257cc
Exhaust Port ShapeD-Port
Exhaust Runner Volume87cc
Intake Valve Diameter2.165 in.
Exhaust Valve Diameter1.590 in.
Cylinder Head Bolt StyleTorque to Yield (TTY)
Cylinder Head Bolt Size(10) M11 x 2 x 100, (5) M8 x 1.25 x 45

LS3 Cam Specifications

Engine VersionWet SumpDry 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 Separation117°117°
Camshaft Part Number1262306612631811
Cam Gear Attachment1-Bolt3-Bolt
Cam Gear Poles4x4x
Active Fuel Management (AFM)NoNo
Variable Valve Timing (VVT)NoNo

LS3 Valvetrain

LS3 Valvetrain Specs
Lifter StyleHydraulic Roller
Lifter Link StylePlastic Lifter Tray
Lifter Body Diameter0.842 in.
Pushrod Length7.385 in.
Rocker Arm Mounting StylePedestal
Rocker Arm StyleDie-Cast, Roller Fulcrum
Rocker Ratio1.7
Rocker OffsetIntake Rocker, 6.25mm
Valve Spring StyleBeehive
Valve Spring ColorNatural
Valve Angle15 Degrees
Intake Valve MaterialSteel - Hollow Stem
Intake Valve Dia.2.165 in.
Exhaust Valve MaterialSteel - Solid Stem
Exhaust Valve Dia.1.590 in.
Timing Chain Guide StyleSpring Loaded Tensioner

Other Key LS3 Specs

Throttle Body, Fuel Injectors, Oil Pan Specs & More
Intake ManifoldCar-Style
Throttle Body90mm, 4-Bolt, Gold Blade
Throttle ControlElectronic, Drive-by-Wire
Fuel Injector Part Number12576341
Fuel Injector Flow42 lbs./hr. at 58 psi
Flex Fuel Capable (E-85)No
Fuel Injector Length (between O-Rings)1.5 in.
Fuel Injector ConnectorEV6-USCAR
PCME38
Crankshaft Reluctor Ring58x
Camshaft SensorFront mount, 4x
Oil Pan Sump LocationVaries By Model
Oil PumpStandard Volume (.96 c.i. per rev. @ 33 psi)
Oil Pump Part Number12678151 (wet sump), 12623097 (dry sump)
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