The LMF engine is a 5.3L Gen. IV iron-block engine used in GM cargo vans between 2010 and 2014.

For marketing purposes, it was also known as the Vortec 5300. The engine specs and information listed here is for a stock LMF 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 LMF engine? Check out LMF 5.3L Engine Upgrade Guide: Expert Advice for LMF 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 LMF 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.)

LMF 5.3L Vortec 5300 Engine Specs

LMF Performance Specifications

Engine Ratings
Compression Ratio9.6:1
Horsepower Rating301 hp
Torque Rating325 ft./lbs.

LMF Applications

VIN 8th DigitYearMakeModel
42010-14ChevroletExpress AWD
42010-14GMCSavana AWD

LMF Engine Blocks

LMF Engine Block Specs
Casting Numbers12576177, 12576178, 1589779
MaterialIron
Displacement5.3L / 325 c.i.d.
Bore Dia. 3.780 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.

LMF Rotating Assembly

LMF 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 Casting Number (last 3 digits)143
Crankshaft MaterialCast Iron
Crankshaft Casting Number (last 3 digits)216
Crankshaft Main Journal2.559 in.
Crankshaft Rod Journal2.100 in.
Reluctor Wheel58x

LMF Cylinder Heads

LMF Cylinder Head Specs
Casting Numbers799, 243
MaterialAluminum
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

LMF Camshaft Specifications

LMF Camshaft Specifications
Duration @ .050 in. (int./exh.)191°/190°
Valve Lift (int./exh.)0.457 in./0.466 in.
Lobe Separation114°
Cam Gear Attachment1-Bolt
Cam Gear Poles4x
Active Fuel Management (AFM) No
Variable Valve Timing (VVT)Yes

LMF Valvetrain

LMF 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.

Other Key LMF Specs

Throttle Body, Fuel Injectors, Oil Pan Specs & More
Intake ManifoldTruck-Style
Throttle Body87mm, 4-bolt
Throttle ControlElectronic (Drive-by-Wire)
Fuel Injector Part Number12613411
Fuel Injector Flow32 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 ConnectorEV6
ComputerE38
Crankshaft Reluctor Ring58x
Camshaft Sensor LocationFront mount, 4x on cam
Oil PanDeep 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.