GM / Chevy LM7 Vortec 5300

GM / Chevy LM7 Vortec 5300 engineThe GM / Chevy LM7 VORTEC 5300 is a 5.3 L (5,328 cc, 325.13 cu·in) natural aspirated V8 four-stroke liquid-cooled internal combustion gasoline engine, manufactured by General Motors since 1999 to 2007. The GM / Chevy LM7 (VIN code “T”) is a Generation III small block V8 Vortec truck engine The engine was manufactured at St. Catharines, Ontario, USA and Romulus, Michigan, USA.

This engine is a longer-stroked by 9.0 mm (0.35 in) version of the LR4 Vortec 4800. The GM / Chevy LM7 engine has a V8 cast-iron block, two aluminum heads with 16 overhead valves (OHV), and a single camshaft. This engine used a sequential fuel injection system and “Coil-Near-Plugs” ignition system and pressurized lubricating system with a wet sump. The engine is equipped with 78.0 mm (3.07 in) 3-bolts mounted throttle body.

The GM / Chevy LM7 Vortec 5.3 engine produced:

  • In 1999 it produced 273 PS (201 kW; 270 HP) of peak horsepower and 427 N·m (43.5 kg·m, 314.7 ft·lb) of max. torque.
  • From 2000 to 2003 the engine made 290 PS (213 kW; 285 HP) of output power and a torque rating is 441 N·m (45 kg·m, 325 ft·lb)
  • The 2004-2007 engines made 299 PS (220 kW; 295 HP) of horsepower and 454 Nm (46.31 kg·m; 335.0 ft·lb) of peak torque.

General information

Engine Specifications
Engine model GM / Chevy LM7 Vortec 5300
Production 1999-2007
Engine type 4-stroke, V8, OHV, chain driven
Displacement 5.3 L (5,328 cm3, 325.13 cu·in)
Max. horsepower 273 PS (201 kW; 270 HP)
290 PS (213 kW; 285 HP)
299 PS (220 kW; 295 HP)
Max. torque 427 N·m (43.5 kg·m, 314.7 ft·lb)
441 N·m (45.0 kg·m, 325.0 ft·lb)
454 N·m (46.3 kg·m; 335.0 ft·lb)
Ignition system Coil-Near-Plugs
Fuel system Sequential fuel injection
Power adder None
Firing order 1-8-7-2-6-5-4-3
Cooling system Liquid-cooled
Lubricating system Wet sump

Cylinder Block

A 96.0 mm (3.78 in) cylinder bore and 92.0 mm (3.62 in) piston stroke give the LM7 engine a total of 5.3 L (325 CID) of displacement. The compression ratio rating is 9.5:1. The engine used a cast-iron cylinder block with 111.76 mm (4.40 in) of bore spacing. The Vortec 5300 is equipped with dish pistons that are made of cast aluminum alloy and powdered metal I-beam style connecting rods. The connecting rod’s length is 154.89 mm (6.098 in). Each piston is fitted with two compression rings and a single oil ring.

Cylinder block
Cylinder block alloy Cast-iron
Compression ratio: 9.5:1
Cylinder bore: 96.0 mm (3.78 in)
Piston stroke: 92.0 mm (3.62 in)
Cylinder internal diameter (standard): 96.000-96.018 mm (3.7795-3.7802 in)
Piston skirt outer diameter (standard): 96.000 mm (3.7795 in)
Number of piston rings (compression / oil): 2/1
Connecting rod big end diameter (standard): 56.505-56.525 mm (2.2246-2.2254 in)
Connecting rod small end diameter (standard): 24.000 mm (0.9449 in)
Piston pin diameter: 23.997-24.000 mm (0.9448-0.9449 in)
Side clearance (Top): 0.040-0.085 mm (0.0016-0.0033 in)
Side clearance (Second): 0.040-0.078 mm (0.0016-0.0031 in)
Side clearance (Oil): 0.012-0.200 mm (0.0005-0.0079 in)
Ring end gap (Top): 0.230-0.440 mm (0.0091-0.0173 in)
Ring end gap (Second): 0.440-0.700 mm (0.0173-0.0276 in)
Ring end gap (Oil): 0.180-0.750 mm (0.0071-0.0295 in)
Number of main bearings: 5
Crankshaft main journal diameter: 64.993-65.007 mm (2.5588-2.5593 in)
Crankpin journal diameter: 53.318-53.338 mm (2.0991-2.0999 in)
Crankshaft center distance: 46 mm (1.81 in)

Cylinder Head

The GM / Chevy LM7 engine has two aluminum heads with 2 valves per cylinder (16 in total) and single camshaft driven by the crankshaft via a chain. The intake port has a cathedral shape with 200 cc intake runner volume and the exhaust has an oval shape with 70 cc exhaust runner volume. Intake and exhaust valves era made of steel with a solid stem. Valves are operated via pedestal mounting rocker arms.

Cylinder head
Cylinder head alloy Aluminium
Valve arrangement: OHV, chain driven
Valves:: 2 (16 valves in total)
Head height: 120.2 mm (4.7323 in)
Intake timig: 191°
Exhaust timig: 190°
Valve lift (INTAKE): 11.60 mm (0.457 in)
Valve lift (EXHAUST): 11.84 mm (0.466 in)
Valve head diameter (INTAKE): 48.0 mm (1.8898 in)
Valve head diameter (EXHAUST): 39.4 mm (1.5512 in)
Valve steam diameter (INTAKE): 7.955-7.976 mm (0.3132-0.314 in)
Valve steam diameter (EXHAUST): 7.955-7.976 mm (0.3132-0.314 in)
Valve spring free length (INTAKE): 52.9 mm (2.0827 in)
Valve spring free length (EXHAUST): 52.9 mm (2.0827 in)
Camshaft lobe lift (INTAKE): 6.96 mm (0.274 in)
Camshaft lobe lift (EXHAUST): 6.82 mm (0.2685 in)
Camshaft journal diameter : 54.99-55.04 mm (2.165-2.1669 in)

Tightening torque

Tightening torque settings
Connecting rod bolts Step 1: 20 Nm (2.04 kg·m; 14.76 ft·lb)
Step 2: Turn all bolts: 70°
Crankshaft bearing cap bolts Step 1: 20 Nm (2.04 kg·m; 14.76 ft·lb)
Step 2: Turn inner bolts: 80° turn outer bolts: 51°
Flywheel bolts Step 1: 20 Nm (2.04 kg·m; 14.76 ft·lb)
Step 2: 50 Nm (5.1 kg·m; 36.9 ft·lb)
Step 3: 100 Nm (10.2 kg·m; 73.8 ft·lb)
Cylinder head bolts Step 1: 30 Nm (3.06 kg·m; 22.14 ft·lb)
Step 2: Turn all bolts: 90°
Step 3: Turn all bolts excluding the medium length bolts at the front and rear of each head: 90°
Step 4: Turn all medium length bolts at the front and rear of each head: 50°
Valve rocker arm bolts 30 Nm (3.06 kg·m; 22.14 ft·lb)

Service Data

The engine oil with a viscosity of 5W-30 is recommended for the LR4, refilling oil capacity is 5.7 L (6.02 US. qt, 5.02 Imp. qt.). A recommended spark plug is AC Delco 41-985 Iridium with 1.01 mm (0.0398 in) spark plug gap.

Oil system
Lubrication system: Wet sump
Oil type: 5W-30
Oil capacity: 5.7 L (6.02 US. qt, 5.02 Imp. qt.)
Oil change interval: 12,000 km (7,500 miles)
Fuel system
Type: Sequential multi-port fuel injection
Fuel Injector Flow: 1999: 2.742 gm/sec (21.8 lb/hr) at 58 psi
2000 : 3.125 gm/sec (24.8 lb/hr) at 58 psi
2001-2007: 3.180 gm/sec (25.2 lb/hr) at 58 psi
Ignition system
Type: Coil-Near-Plugs
Spark plug: AC Delco 41-985 Iridium
Spark plug gap: 1.01 mm (0.03980.0398 in)
Spark plug torque: 15 N·m (1.5 kg·m, 11.1 ft·lb)

Applications

Model Years Produced
Chevrolet Silverado 1500 1999-2007
Chevrolet Tahoe 1999-2006
Chevrolet Suburban 1500 1999-2006
Chevrolet Avalanche 2002-2006
ChevroletExpress 2003-2007
GMC Sierra 1500 1999-2007
GMC Yukon 1999-2006
GMC Yukon XL 1500 1999-2006
GMC Savana 2003-2007
Cadillac Escalade (2WD) 2002-2005

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