GM / Chevy LY2 VORTEC 4800 is a 4.8 L (4807 cc, 293.34 cu·in) natural aspirated V8 90° four-stroke liquid-cooled internal combustion gasoline engine, manufactured by General Motors from 2007 to 2009. The LY2 (VIN code “C”) is the smallest engine of the Generation IV Vortec truck engines.
The cylinder bore is 96.1 mm (3.78 in) and the piston stroke is 83.0 mm (3.27 in). The compression ratio rating is 9.1:1. This engine produced from 264 PS (194 kW; 260 HP) to 300 PS (220 kW; 295 HP) of horsepower and from 400 N·m (40.8 kg·m, 294.8 ft·lb) to 414 N·m (42.2 kg·m, 305.1 ft·lb) of torque.
The GM LY2 features:
- OHV design with 2 valves per cylinder (16 in total)
- Cast-iron cylinder block with five main bearings
- Aluminum cilinder heads
- Cast aluminum pistons
- Powdered metal connecting rods
- Throttle body 84.0 mm (3.31 in) with electronic (Drive-by-Wire) control
- Cast nodular iron crankshaft
- Coil-Near-Plug ignition system
- Sequential Fuel Injection (SFI)
General information
| Engine Specifications | |
| Engine model | GM / Chevy LY2 Vortec 4800 |
| Production | 2007-2009 |
| Engine type | 4-stroke, V8, OHV, chain driven |
| Displacement | 4.8 L, 4,807 cm3, (293 CID) |
| Max. horsepower | From 264 PS (194 kW; 260 HP) to 300 PS (220 kW; 295 HP) |
| Max. torque | From 400 N·m (40.8 kg·m, 294.8 ft·lb) to 414 N·m (42.2 kg·m, 305.1 ft·lb) |
| Ignition system | Coil-Near-Plugs |
| Fuel system | Sequential fuel injection (SFI) |
| Power adder | None |
| Firing order | 1-8-7-2-6-5-4-3 |
| Cooling system | Liquid-cooled |
| Lubricating system | Wet sump |
Cylinder Block and Head
| Cylinder block | |
| Cylinder block alloy: | Cast-iron |
| Compression ratio: | 9.1:1 |
| Cylinder bore: | 96.1 mm (3.78 in) |
| Piston stroke: | 83.0 mm (3.27 in) |
| Cylinder internal diameter (standard): | 96.000-96.018 mm (3.7795-3.7802 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) |
| Piston pin diameter: | 23.952-23.955 mm (0.943-0.9431 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: | 64.992-65.008 mm (2.5587-2.5594 in) |
| Crankpin journal diameter: | 53.318-53.338 mm (2.0991-2.0999 in) |
| Crankshaft center distance: | 41.5 mm (1.635 in) |
| Cylinder head | |
| Cylinder head alloy: | Aluminum |
| Valve arrangement: | OHV, chain driven |
| Valves: | 2,(16 valves in total) |
| 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 height (INTAKE): | 7.2 mm (0.2835 in) |
| Camshaft lobe height (EXHAUST): | 7.2 mm (0.2835 in) |
| Camshaft journal diameter : | 54.990-55.040 mm (2.165-2.1669 in) |
Head tightening torque
| 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° |
Service Data
| Oil system | |
| Lubrication system: | Pressurized lubrication |
| Oil type: | – |
| Recommended oil: | 5W-30, 10W-30 |
| Oil 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 pressure: | 41 kPa (5.9 psi) at 1000 rpm 124 kPa (18 psi) at 2,000 rpm 165 kPa (23.9 psi) at 4,000 rpm |
| Ignition system | |
| Type: | Coil-Near-Plug |
| Spark plug: | AC Delco 41-985 |
| Spark plug gap: | 1.01 mm (0.0398 in) |
| Spark plug torque: | 15 N·m (1.5 kg·m, 11.1 ft·lb) |
Applications
| Model | Years Produced |
| Chevrolet Express | 2008–2009 |
| Chevrolet Silverado | 2007–2009 |
| Chevrolet Tahoe | 2007–2009 |
| GMC Sierra | 2007–2009 |
| GMC Yukon | 2007–2009 |
| GMC Savana | 2008–2009 |
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