GM / Chevy LY2 Vortec 4800

GM / Chevy LY2The GM / Chevy LY2 (VIN – “C”) is a 4.8 l (293 natural aspirated V8 90° four-stroke gasoline engine from a Generation IV small-block V8 truck engine series. The engine was manufactured from 2007 to 2009.

The GM LY2 Vortec 4800 features a V8 90° cast-iron cylinder block with a five-bearings crankshaft, two aluminum heads, a single one-piece cast camshaft, and two valves per cylinder (16 in total). The LY2 used a sequential multi-port fuel injection system and 84.0 mm (3.31 in) throttle body with electronic (Drive-by-Wire) control and coil-near-plugs ignition system with iridium spark plugs and low resistance spark plug wires

The compression ratio rating is 9.1:1. Cylinder bore and piston stroke are 96.0 mm (3.78 in) and 83.0 mm (3.27 in), respectively. The engine produced from 264 PS (194 kW; 260 HP) to 300 PS (220 kW; 295 HP). The maximum torque is from 400 N·m (40.8 kg·m, 294.8 ft·lb) to 414 N·m (42.2 kg·m, 305.1 ft·lb).

General information

Engine Specifications
Engine codeGM / Chevy LY2 Vortec 4800
LayoutFour stroke, V8
Fuel typeGasoline (petrol)
Displacement4.8 L, (293 cu in)
Fuel systemSequential fuel injection
Power adderNone
Power output From 264 PS (194 kW; 260 HP)
to 300 PS (220 kW; 295 HP)
Torque output From 400 N·m (40.8 kg·m, 294.8 ft·lb)
to 414 N·m (42.2 kg·m, 305.1 ft·lb)
Firing order1-8-7-2-6-5-4-3
Dimensions (L x W x H):

Cylinder block

The LY2 has a cast-iron cylinder block with a five-bearings crankshaft supported system. The crankshaft journal diameter is 65.0 mm (2.55 in), the crankpin diameter is 53.3 mm (2.09 in). The crankshaft is a cast nodular iron.

The cylinder bore is 96.0 mm (3.78 in), piston stroke is 83.0 mm (3.27 in) and the compression ratio rating is 9.1:1. The GM LY2 motor has two compression and one oil control rings. The pistons are cast aluminum. The piston pins are chromium steel and are a full-floating design. The connecting rods are powdered metal.

Cylinder block
Cylinder block alloyCast-iron
Compression ratio:9.1:1
Cylinder bore:96.0 mm (3.78 in)
Piston stroke:83.0 mm (3.27 in)
Number of piston rings (compression / oil):2 / 1
Number of main bearings:5
Cylinder inner diameter (standard):96.000-96.018 mm (3.7795-3.7802 in)
Piston skirt diameter (standard):96.000 mm (3.7795 in)
Piston pin outer diameter:23.952-23.955 mm (0.943-0.9431 in)
Piston ring side clearance:Top0.040-0.085 mm (0.0016-0.0033 in)
Second0.040-0.078 mm (0.0016-0.0031 in)
Oil0.012-0.200 mm (0.0005-0.0079 in)
Piston ring end gap:Top0.23-0.44 mm (0.0091-0.0173 in)
Second0.44-0.70 mm (0.0173-0.0276 in)
Oil0.18-0.75 mm (0.0071-0.0295 in)
Connecting rod small end diameter24.000 mm (0.9449 in)
Connecting rod big end diameter:56.505-56.525 mm (2.2246-2.2254 in)
Crankshaft main journal diameter:64.993-65.007 mm (2.5588-2.5593 in)
Crankpin diameter:53.318-53.338 mm (2.0991-2.0999 in)

Cylinder head

The cylinder heads are made of strong, light aluminum alloy which gives it good cooling efficiency. The camshaft is driven by a single chain. The timing chain transmits the rotational movement from the crankshaft to the camshafts. Valves are operated via pedestal mounting rocker arms.

Cylinder head
Block head alloyAluminium
Valve Arrangement:OHV, chain drive
Valves:16 (2 valves per cylinder)
Intake valve timing:191°
Exhaust valve timing:190°
Valve head diameter:INTAKE
Valve length:INTAKE
Valve stem diameter:INTAKE7.955-7.976 mm (0.3132-0.314 in)
EXHAUST7.955-7.976 mm (0.3132-0.314 in)
Valve spring free length:INTAKE52.9 mm (2.0827 in)
EXHAUST52.9 mm (2.0827 in)
Camshaft lobe lift:INTAKE7.2 mm (0.2835 in)
EXHAUST7.2 mm (0.2835 in)
Camshaft journal diameter:54.99-55.04 mm (2.165-2.1669 in)

Head tightening procedure and torque specs:
M8 bolts:

  • 30 Nm (3.06 kg·m; 22.14 ft·lb)

M11 bolts:

  • Step 1: 30 Nm (3.06 kg·m; 22.14 ft·lb)
  • Step 2: Turn all bolts: 90°
  • Step 3: Turn all bolts: 70°

Maintenance data

Compression pressure
Standard12.5 kg/m2 / 300 rpm
Minimun7.0 kg/m2 / 300 rpm
Compression differential limit between cylinders1.0 kg/m2 (15 psi) / 300 rpm
Oil system
Oil consumption , L/1000 km (qt. per miles)up to 0.5 (1 qt. per 1200 miles)
Recommended engine oil 5W-30, 10W-30
Oil type API
Engine oil capacity (Refill capacity) Without oil filter: 5.2 L (5.5 US. qt, 4.6 Imp. qt.)
With oil filter: 5.7 L (6.0 US. qt, 5.00 Imp. qt.)
Oil change interval, km (miles)12,000 km (7,500 miles)
Oil Pressure 41 kPa at 1,000 rpm
124 kPa at 2,000 rpm
165 kPa at 4,000 rpm
Ignition system
Spark plugAC Delco: 41-985 Iridium
Spark plug gap1.01 mm (0.0398 in)

Vehicle applications

ModelYears Produced
Chevrolet Express2008–2009
Chevrolet Silverado2007–2009
Chevrolet Tahoe2007–2009
GMC Sierra2007–2009
GMC Yukon2007–2009
GMC Savana2008–2009
Author: Sergei Wers
About: Co-founder and CEO of a multi-brand auto repair shop (engine repair, chassis repair, body repair and painting) for over 15 years. I have been developing internet sites with technical specifications for more than seven years.

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