The LMG engine is a 5.3L Gen. IV iron-block engine used in GM trucks and SUVs between 2007 and 2014. For marketing purposes, it was also known as the Vortec 5300. The information listed here is for a stock LMG 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 LMG engine? Check out LMG 5.3L Engine Upgrade Guide: Expert Advice for LMG 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 LMG 5.3L Vortec 5300.
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.)
…
LMG 5.3L Vortec 5300 Engine Specs
LMG Performance Specifications
| Engine Ratings | |
|---|---|
| Compression Ratio (2007-09) | 9.9:1 |
| Compression Ratio (2010-14) | 9.6:1 |
| Horsepower Rating | 310-326 hp |
| Torque Rating | 335-348 ft./lbs. |
LMG Applications
| VIN 8th Digit | Year | Make | Model |
|---|---|---|---|
| 0 | 2007-13 | Chevrolet | Avalanche |
| 0 | 2007-13 | Chevrolet | Silverado |
| 0 | 2007-13 | GMC | Sierra |
| 0 | 2007-14 | Chevrolet | Suburban |
| 0 | 2007-14 | Chevrolet | Tahoe |
| 0 | 2007-14 | GMC | Yukon |
LMG Engine Blocks
| LMG Engine Block Specs | |
|---|---|
| Casting Numbers | 12576177, 12576178, 1589779 |
| Material | Iron |
| Displacement | 5.3L / 325 c.i.d. |
| Bore Dia. | 3.780 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. |
LMG Rotating Assembly
| LMG Rotating Assembly Specs | |
|---|---|
| Piston Material | Hypereutectic Cast Aluminum Alloy |
| Piston Style (2007-09) | Flat Top |
| Piston Style (2010-14) | Flat Top with Valve Reliefs |
| Piston Volume (2007-09) | 0cc |
| Piston Volume (2010-14) | +3cc |
| 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 3 digits) | 143 |
| Crankshaft Material | Cast Iron |
| Crankshaft Casting Number (last 3 digits) | 216 |
| Crankshaft Main Journal | 2.559 in. |
| Crankshaft Rod Journal | 2.100 in. |
| Reluctor Wheel | 58x |
LMG Cylinder Heads
| LMG Cylinder Head Specs | |
|---|---|
| Casting Numbers | 799, 243 |
| 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 |
LMG Camshaft Specifications
| LMG Camshaft Specifications | ||
|---|---|---|
| Years | 2007-09 | 2010-14 |
| Part Number | 12593207 | 12625436 |
| Duration @ .050 in. (int./exh.) | 193°/193° | 196°/201° |
| Valve Lift (int./exh.) | 0.482 in./0.482 in. | 0.481 in./0.481 in. |
| Lobe Separation | 116° | 116°+2 |
| Cam Gear Attachment | 1-Bolt | 1-Bolt |
| Cam Gear Poles | 4x | 4x |
| Active Fuel Management (AFM) | Yes | Yes |
| Variable Valve Timing (VVT) | No | Yes |
LMG Valvetrain
| LMG 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. |
Other Key LMG Specs
| Throttle Body, Fuel Injectors, Oil Pan Specs & More | |
|---|---|
| Intake Manifold | Truck-Style |
| Throttle Body | 87mm, 4-bolt |
| Throttle Control | Electronic (Drive-by-Wire) |
| Fuel Injector Part Number | 12613411 |
| Fuel Injector Flow | 32 lb./hr. @ 43psi; 36 lb./hr. @ 58 psi |
| Flex Fuel Capable (E-85) | Yes |
| Fuel Injector Length (between O-Rings) | 1.900 in. |
| Fuel Injector Connector | EV6 |
| Computer | 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.) |
…
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.
[…] LMG 5.3L Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More […]
What are some performance upgrade bolt on part numbers that I can purchase for more torque etc
LMG vs LC9
LMG vs L33
[…] related to the LS6. The engine has flex-fuel capability. The engine is close siblings with the LMG which shared many of the same features…except the LMF isn’t saddled with […]
1
[…] I’m swapping a low-mileage 5.3L LS engine from a 2011 GMC truck into a 1982 Cutlass drag car. The engine will be upgraded with a Trick Flow® 455 HP GenX® top end […]
I own 2007 chevy Silverado with 5.3 L motor. Put K&N filter, single dump 3” exhaust, new plugs and wires, and performance tune by Collingdale speed shop. It completely changed truck for the better. Total cost $1600 I smile every time I floor it.
Will a 2011 5.3 Yukon engine work on a 2007 Suburban
What is the weight of the crankshaft hanging on a linear weight scale.
What is the weight of the threaded hanger before threaded into the crankshaft harmonic bolt hole.
What is the weight of the camshaft hanging on a linear weight scale.
What is the compressed force in inch pounds and foot pounds of intake and exhaust valve springs compressed.
What is the friction of the crankshaft in the block caped and torqued to spec for the crankshaft only turned , with assembly lube.
What is the friction of the piston rings on the piston and connecting rod pulled through the cylinder .
What is the friction of the rear main seal on the crankshaft only, to turn the crankshaft only.
What is the vacuum for the vacuum stroke when the Piston reached bottom dead center for the compression stroke with compression stroke ratio to aquire 150 psi compression on the compression stroke at top dead center.
can converting to dual exhaust increase performance for my LTZ 5.3L? If so, what mufflers are needed?