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.)
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LY2 4.8L Vortec 4800 Engine Specs
LY2 Performance Specifications
| LY2 Engine Ratings | |
|---|---|
| Compression Ratio | 9.1:1 |
| Horsepower Rating | 260-295 hp |
| Torque Rating | 295-305 ft.-lbs. |
LY2 Applications
| LY2 Applications | |||
|---|---|---|---|
| VIN 8th Digit | Year | Make | Model |
| C | 2007-09 | Chevrolet | Silverado |
| C | 2007-09 | Chevrolet | Tahoe |
| C | 2007-09 | GMC | Sierra |
| C | 2007-09 | GMC | Yukon |
| C | 2008-09 | Chevrolet | Express |
| C | 2008-09 | GMC | Savana |
LY2 Engine Block Specs
| LY2 Block Specs | |
|---|---|
| Casting Number | 12576177, 12576178, 1589779 |
| Material | Iron |
| Displacement | 4.8L / 293 c.i.d. |
| Bore Dia. | 3.780 in. |
| Stroke | 3.267 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 in. Bore 2/4 = 2.326 in. Bore 3 = 2.307 in. |
| Cam-to-Crank Centerline | 4.914 in. |
LY2 Rotating Assembly
| LY2 Rotating Assembly Specs | |
|---|---|
| Piston Material | Hypereutectic Cast Aluminum Alloy |
| Piston Style | Flat Top with valve reliefs |
| Piston Volume | 0cc |
| Wrist Pin Dia. | 0.9431 in. (Full Floating) |
| Connecting Rod Material | Powdered Metal |
| Connecting Rod Style | I-Beam |
| Connecting Rod Length | 6.098 in. |
| Connecting Rod Housing Bore | 2.225 in. |
| Connecting Rod Bolts | M9 x 1 x 43 |
| Connecting Rod Casting Number (last three digits) | 121 |
| Crankshaft Material | Cast Iron |
| Crankshaft Casting Number (last three digits) | 482 |
| Crankshaft Main Journal Dia. | 2.559 in. |
| Crankshaft Rod Journal Dia. | 2.100 in. |
| Reluctor Wheel | 58x |
LY2 Cylinder Heads
| LY2 Cylinder Head Specs | |
|---|---|
| Casting Numbers | 799 |
| Material | Aluminum |
| Combustion Chamber Volume | 65cc |
| Intake Port Shape | Cathedral |
| Intake Runner Volume | 210cc |
| Exhaust Port Shape | D-Port |
| Exhaust Runner Volume | 75cc |
| Intake Valve Diameter | 2.000 in. |
| Exhaust Valve Diameter | 1.575 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 |
LY2 Camshaft Specs
| Years | 2007-09 |
|---|---|
| Duration @ .050 in. (int./exh.) | 191°/190° |
| Valve Lift (int./exh.) | 0.457 in./0.466 in. |
| Lobe Separation Angle | 114° |
| Cam Gear Attachment | 1-Bolt |
| Cam Gear Poles | 4x |
| Active Fuel Management (AFM) | No |
| Variable Valve Timing (VVT) | No |
LY2 Valvetrain
| LY2 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 | None |
| Valve Spring Style | Beehive |
| Valve Spring Color | Natural |
| Valve Angle | 15 Degrees |
| Intake Valve Material | Steel, Solid Stem |
| Intake Valve Dia. | 2.000 in. |
| Exhaust Valve Material | Steel, Solid Stem |
| Exhaust Valve Dia. | 1.575 in. |
LY2 Throttle Body, Fuel Injector Specs & More
| Years | 2007-09 |
|---|---|
| Intake Manifold | Truck-Style |
| Throttle Body | 87mm, 4-bolt |
| Throttle Control | Electronic, Drive-by-Wire |
| Fuel Injector Part Number | 12580681 |
| Fuel Injector Flow | 29.6 lb./hr. @ 58 psi |
| Flex Fuel Capable | No |
| Fuel Injector Length Between O-Rings | 1.900 in. |
| Fuel Injector Connector | EV6 |
| PCM | E38 |
| Crankshaft Reluctor Ring | 58x |
| Camshaft Sensor Location | Front mount, 4x on Cam |
| Oil Pan | Deep Rear Sump |
| Oil Pump | Standard Flow (0.96 c.i. per rev.) |
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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.
Great information! Thank you
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.
[…] L20 is a 4.8L Gen. IV iron block truck engine. It replaced the LY2 in 2010. It was upgraded with Variable Valve Timing (VVT) and Flex Fuel technology. It was […]
[…] LY2 4.8L Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More […]
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
WILL AN LY2 OUT OF A 2008 VAN FIT IN A 2008 SILVERADO?
THANKS
JOHN
It will indeed
Mine came with the 242 heads
In the process of selling my 2008 Silverado, the body is rusting out.Has the LY2 with 200,000 miles on it.Runs like new,never had a problem.