Engine Guides / LS Engines

LY2 4.8L Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More

The LY2 is a 4.8L iron-block Gen. III engine that was introduced in 2007. It replaced the LR4 as the Vortec 4800. It was available in GM pickups, vans, and SUVs until 2009.

These engines are strong and durable. Many people use them with boost or nitrous. With upgraded internals, the blocks can handle over 1,000 hp.

The engine specs and information here is for a stock LY2 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 LY2 engine? Check out LY2 4.8L Engine Upgrade Guide: Expert Advice for LY2 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 LY2 4.8L Vortec 4800.

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.)

LY2 4.8L Vortec 4800 Engine Specs

LY2 Performance Specifications

LY2 Engine Ratings
Compression Ratio9.1:1
Horsepower Rating260-295 hp
Torque Rating295-305 ft.-lbs.

LY2 Applications

LY2 Applications
VIN 8th DigitYearMakeModel

LY2 Engine Block Specs

LY2 Block Specs
Casting Number12576177, 12576178, 1589779
Displacement4.8L / 293 c.i.d.
Bore Dia. 3.780 in.
Stroke3.267 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 in. Bore 2/4 = 2.326 in. Bore 3 = 2.307 in.
Cam-to-Crank Centerline4.914 in.

LY2 Rotating Assembly

LY2 Rotating Assembly Specs
Piston MaterialHypereutectic Cast Aluminum Alloy
Piston StyleFlat Top with valve reliefs
Piston Volume0cc
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 Casting Number (last three digits)121
Crankshaft MaterialCast Iron
Crankshaft Casting Number (last three digits)482
Crankshaft Main Journal Dia.2.559 in.
Crankshaft Rod Journal Dia.2.100 in.
Reluctor Wheel58x

LY2 Cylinder Heads

LY2 Cylinder Head Specs
Casting Numbers799
Combustion Chamber Volume65cc
Intake Port ShapeCathedral
Intake Runner Volume210cc
Exhaust Port ShapeD-Port
Exhaust Runner Volume75cc
Intake Valve Diameter2.000 in.
Exhaust Valve Diameter1.575 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

LY2 Camshaft Specs

Duration @ .050 in. (int./exh.)191°/190°
Valve Lift (int./exh.)0.457 in./0.466 in.
Lobe Separation Angle114°
Cam Gear Attachment1-Bolt
Cam Gear Poles4x
Active Fuel Management (AFM)No
Variable Valve Timing (VVT)No

LY2 Valvetrain

LY2 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 OffsetNone
Valve Spring StyleBeehive
Valve Spring ColorNatural
Valve Angle15 Degrees
Intake Valve MaterialSteel, Solid Stem
Intake Valve Dia.2.000 in.
Exhaust Valve MaterialSteel, Solid Stem
Exhaust Valve Dia.1.575 in.

LY2 Throttle Body, Fuel Injector Specs & More

Intake ManifoldTruck-Style
Throttle Body87mm, 4-bolt
Throttle Control Electronic, Drive-by-Wire
Fuel Injector Part Number 12580681
Fuel Injector Flow29.6 lb./hr. @ 58 psi
Flex Fuel CapableNo
Fuel Injector Length Between O-Rings 1.900 in.
Fuel Injector Connector EV6
Crankshaft Reluctor Ring58x
Camshaft Sensor LocationFront mount, 4x on Cam
Oil Pan
Deep Rear Sump
Oil PumpStandard Flow
(0.96 c.i. per rev.)

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. Great information! Thank you

  2. Dennis Gray says:

    I recently purchased a 2008 Chevy Silverado with an LY2 4.8L V8. 8th vin letter
    ” C “.
    I have tried to research, and speak to people about this engine,even calling GM on whether or not it uses fuel management/cylinder displacement, as after reading any number of horror stories about issues with such technology, I wanted nothing to do with it !
    The dealership, ( not GM/Chevy ) told me it didn’t use AFM Etc.
    Even the manufacturer of the OBD2 devices used to circumvent AFM, has told me no 4.8 L used AFM/cylinder displacement, therefore they do not make such a device for the 4.8L.
    Basically most say no 4.8L engines use this technology!
    However, when I researched the build sheet, it describes cylinder displacement ?
    Coming from a manufacturing back ground, I know how paperwork sometimes says one thing, and reality is something different !
    I have tried putting it through it’s paces, to see if I could tell any noticable changes as I drive it, but nothing I have seen so far,( change in R.P.M. strange sounds etc. ) has given me a clue.
    This year does have a DIC in the dash display, but no hint of showing any V8 to V4 displays.
    What am I to believe ?
    Any thoughts would be much appreciated !
    Thank You in advance for your time !

    • If no one has answered you question, the LY2 4.8 didn’t have AFM. A quick check if you still have questions is to look at the valley cover. A Non-AFM engine has a smooth valley cover other than the breather fitting on the passenger front corner. AFM covers have oil passages in them which cause the covers to have ridges on them.

  3. Pingback: L20 4.8L Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More

  4. Pingback: LY2 4.8L Engine Upgrade Guide: Expert Advice for LY2 Engine Mods to Maximize Performance

  5. This is a great write up that clarified a lot of things for me but it is also misleading in the fact that the ly2 is a gen IV and not a gen 3 like this article states. Even on another article from this same website, it calls it a gen IV. Other than that, this is absolutely fantastic

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