LS Engines

L99 6.2L Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More

The L99 is a 6.2L, Gen. 4, small block engine used in the Chevy Camaro SS from 2010-2015. The information listed here is for a stock L99 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.

[Looking to upgrade your L99 engine? Check out L99 6.2L Engine Upgrade Guide: Expert Advice for L99 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 L99 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.)

L99 6.2L Engine Specs

L99 Performance Specifications

Engine Ratings
Compression Ratio10.4:1
Horsepower Rating400 hp
Torque Rating410 ft./lbs.

L99 Applications

VIN 8th DigitYearMakeModel
J2010-15ChevroletCamaro SS (w/ auto trans.)

L99 Engine Blocks

L99 Block Specs
Casting Number12584724
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.

L99 Rotating Assembly

L99 Rotating Assembly Specs
Piston MaterialHypereutectic Cast Aluminum Alloy
Piston StyleFlat Top with Valve Reliefs
Piston Volume+3cc
Wrist Pin Dia.0.9431 in. (full floating)
Connecting Rod MaterialPowdered Metal
Connecting Rod StyleI-Beam
Connecting Rod Length6.098 in.
Connecting Rod Housing Bore2.225 in.
Connecting Rod BoltsM9 x 1 x 43
Connecting Rod Part Number12649190
Crankshaft MaterialCast Iron
Crankshaft Part Number12588612
Crankshaft Main Journal2.559 in.
Crankshaft Rod Journal2.100 in.
Reluctor Wheel58x

L99 Cylinder Heads

L99 Cylinder Head Specs
Casting Numbers823
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

L99 Cam Specifications

L99 Camshaft Specs
Camshaft Part Number12623066
Duration @ .050 in. (int./exh.)195°/201°
Valve Lift (int./exh.)0.500 in./.492 in.
Lobe Separation115°
Cam Gear Attachment1-Bolt
Cam Gear Poles4x
Active Fuel Management (AFM)Yes
Variable Valve Timing (VVT)Yes

L99 Valvetrain

L99 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
Valve Spring StyleBeehive
Valve Spring ColorNatural
Valve Angle15 Degrees
Intake Valve MaterialSteel - Solid 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 L99 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)1.500 in.
Fuel Injector ConnectorEV6-USCAR
Crankshaft Reluctor Ring58x
Camshaft SensorFront mount, 4x
Oil Pan Sump LocationCenter sump
Oil PumpHigh volume (1.25 c.i. per rev. @ 33 psi)

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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  1. Pingback: L99 6.2L Engine Upgrade Guide: Expert Advice for L99 Mods to Maximize Performance - OnAllCylinders

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  3. Ronald Miller says:

    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?

  4. You are not fine Ronald. They also don’t list the valve lift specs quite right. They are different for the AFM cylinders and the non-AFM cylinders. The cams ARE different too, if you try using an AFM cam on a non-AFM motor and vise versa, you will get a hard misfire guaranteed. I’ve done it. Now if you get an LS3 cam and delete AFM and tune it, your probably ok.
    As of today according to GM service information the lift specs for an 11 Camaro L99

    Valve Lift – Exhaust – Non Active Fuel Management
    12.52 mm
    0.493 in

    •Valve Lift – Exhaust – Active Fuel Management
    12.74 mm
    0.501 in

    •Valve Lift – Intake – Non Active Fuel Management
    12.69 mm
    0.499 in

    •Valve Lift – Intake – Active Fuel Management
    12.91 mm
    0.508 in

    • I have a 2010 ss camaro I was wondering if some or the 2010 or the earlyer modle camaro did they not come win afm because mine 2010 seems like it don’t have it or note it is a automatic car ss thanks.

  5. vrey helful m question is does the vvt dekete kit work nd for the AFM lifters i have no ifed could you educate me>

  6. Will W-pistons fit on J-engines? (W=LS3 w man. J=L99 w auto). Will rebuild a Camaro 2012 2SS with auto and delete AFM.

    • Glenn Wratni says:

      All 6.2 motors use same 4.065 dia. pistons. Compression ratio is the same for LS3 & L99 motors. So you should be fine.

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