GM Service Manual Online
For 1990-2009 cars only

Application

Specification

Metric

English

General

  • Engine Type

V8

  • Displacement

8.1L

496 CID

  • RPO

L18

  • VIN - Light Duty

G

  • VIN - Medium Duty

E

  • Bore

107.95 mm

4.25 in

  • Stroke

111.0 mm

4.37 in

  • Compression Ratio

9.1:1

  • Firing Order

1-8-7-2-6-5-4-3

  • Spark Plug Gap

1.52 mm

0.06 in

Block

  • Crankshaft Main Bearing Bore Diameter

74.606-74.622 mm

2.9372-2.9379 in

  • Cylinder Bore Diameter - Production

107.95-107.968 mm

4.25-4.2507 in

  • Cylinder Bore Diameter - Service

107.94-107.99 mm

4.2496-4.2516 in

  • Cylinder Bore Out-of-Round - Production, Maximum Minus Minimum Bore Diameter

0.018 mm

0.0007 in

  • Cylinder Bore Out-of-Round - Service, Maximum Minus Minimum Bore Diameter

0.05 mm

0.002 in

  • Cylinder Bore Taper - Production

0.018 mm

0.0007 in

  • Cylinder Bore Taper - Service Thrust Axis

0.05 mm

0.002 in

  • Cylinder Bore Taper - Service Pin Axis

0.05 mm

0.002 in

  • Cylinder Head Deck Height - from Centerline of Crankshaft

259.875-260.125 mm

10.231-10.241 in

  • Cylinder Head Deck Surface Flatness - Entire Face

0.1 mm

0.004 in

  • Cylinder Head Deck Surface Flatness - Within 150 mm (6 in)

0.05 mm

0.002 in

  • Valve Lifter Bore Diameter

21.417-21.443 mm

0.843-0.844 in

Camshaft

  • Camshaft Bearing Inside Diameter

49.548-49.573 mm

1.9507-1.9517 in

  • Camshaft Journal Diameter

49.472-49.522 mm

1.9477-1.9497 in

  • Camshaft Lobe Lift - Exhaust

6.973-7.075 mm

0.2745-0.2785 in

  • Camshaft Lobe Lift - Intake

6.924-7.026 mm

0.2726-0.2766 in

  • Camshaft Runout - Production

0.051 mm

0.002 in

  • Camshaft Runout - Service

0.076 mm

0.003 in

Connecting Rod

  • Connecting Rod Bearing Clearance - Production

0.033-0.068 mm

0.0013-0.0027 in

  • Connecting Rod Bearing Clearance - Service

0.033-0.081 mm

0.0013-0.0032 in

  • Connecting Rod Side Clearance

0.384-0.686 mm

0.0151-0.027 in

Crankshaft

  • Connecting Rod Journal Diameter

55.854-55.87 mm

2.199-2.1996 in

  • Connecting Rod Journal Out-of-Round - Production

0.0102 mm

0.0004 in

  • Connecting Rod Journal Taper - Production

0.0102 mm

0.0004 in

  • Crankshaft End Play

0.127-0.35 mm

0.005-0.0138 in

  • Crankshaft Main Bearing Clearance - #1, #2, #3, #4 Production

0.022-0.057 mm

0.0008-0.0022 in

  • Crankshaft Main Bearing Clearance - #5 Production

0.034-0.069 mm

0.0013-0.0027 in

  • Crankshaft Main Bearing Clearance - #1, #2, #3, #4 Service

0.022-0.089 mm

0.0008-0.0035 in

  • Crankshaft Main Bearing Clearance - #5 Service Limit

0.035-0.102 mm

0.0014-0.004 in

  • Crankshaft Main Journal Diameter

69.805-69.822 mm

2.7482-2.7489 in

  • Crankshaft Main Journal Out-of-Round - Production

0.0102 mm

0.0004 in

  • Crankshaft Main Journal Taper - Production

0.0102 mm

0.0004 in

  • Crankshaft Runout - Production

0.05 mm

0.002 in

  • Crankshaft Runout - Service

0.065 mm

0.0026 in

Cylinder Head

  • Cylinder Head Height/Thickness

259.875-260.125 mm

10.231-10.241 in

  • Surface Flatness - Block Deck

0.05 mm

0.002 in

  • Surface Flatness - Exhaust Manifold Deck

0.102 mm

0.004 in

  • Surface Flatness - Intake Manifold Deck

0.08 mm

0.003 in

Exhaust Manifold

  • Surface Flatness

0.254 mm

0.01 in

Lubrication System

  • Oil Capacity - Without Filter

5.7L

6.0 Qts

  • Oil Capacity - With Filter

6.15L

6.5 Qts

  • Oil Pressure - Minimum

34 kPa @ 1,000 RPM

5 psi @ 1,000 RPM

  • Oil Pressure - Minimum

69 kPa @ 2,000 RPM

10 psi @ 2,000 RPM

Piston Rings

Piston Ring End Gap

  • First Compression Ring - Production

0.3-0.45 mm

0.012-0.018 in

  • First Compression Ring - Service

0.45-0.675 mm

0.018-0.027 in

  • Second Compression Ring - Production

0.45-0.65 mm

0.017-0.025 in

  • Second Compression Ring - Service

0.675-0.975 mm

0.026-0.039 in

  • Oil Control Ring - Production

0.249-0.759 mm

0.0098-0.0299 in

  • Oil Control Ring - Service

0.373-1.138 mm

0.015-0.045 in

Piston Ring-to-Groove Clearance

  • First Compression Ring

0.031-0.074 mm

0.0012-0.0029 in

  • Second Compression Ring

0.031-0.074 mm

0.0012-0.0029 in

  • Oil Control Ring

0.051-0.203 mm

0.002-0.008 in

Piston and Pins

Piston

  • Piston Diameter

Not Measurable

Not Measurable

  • Piston-to-Bore Clearance

Interference Fit

Interference Fit

Pin

  • Pin-Piston Pin Fit in Connecting Rod Bore-Production

0.010-0.023 mm

0.0004-0.0009 in

  • Pin-Piston Pin Fit in Connecting Rod Bore-Service

0.010-0.023 mm

0.0004-0.0009 in

  • Pin-Piston Pin Clearance-to-Piston Pin Bore-Production

0.003-0.011 mm

0.00019-0.00043 in

  • Pin-Piston Pin Clearance-to-Piston Pin Bore-Service

0.003-0.011 mm

0.00019-0.00043 in

  • Pin-Piston Pin Diameter

26.416-26.419 mm

1.039-1.040 in

Valve System

Valves

  • Valve Face Angle - Exhaust

45 degrees

  • Valve Face Angle - Intake

45 degrees

  • Valve Head Diameter - Exhaust

43.69 mm

1.72 in

  • Valve Head Diameter - Intake

55.63 mm

2.19 in

  • Valve Lash - Exhaust

Net Lash

Net Lash

  • Valve Lash - Intake

Net Lash

Net Lash

  • Valve Seat Angle - Exhaust

46 degrees

  • Valve Seat Angle - Intake

46 degrees

  • Valve Seat Runout - Exhaust

0.05 mm

0.002 in

  • Valve Seat Runout - Intake

0.05 mm

0.002 in

  • Valve Seat Width - Exhaust

1.651-2.159 mm

0.060-0.095 in

  • Valve Seat Width - Intake

0.8-1.2 mm

0.03-0.06 in

  • Valve Stem Diameter - Exhaust

9.431-9.449 mm

0.3713-0.372 in

  • Valve Stem Diameter - Intake

9.436-9.454 mm

0.3715-0.3722 in

  • Valve Stem-to-Guide Clearance - Exhaust - Production

0.03-0.079 mm

0.0012-0.0031 in

  • Valve Stem-to-Guide Clearance - Intake - Production

0.025-0.074 mm

0.001-0.0029 in

  • Valve Stem-to-Guide Clearance - Exhaust - Service

0.03-0.104 mm

0.0012-0.0041 in

  • Valve Stem-to-Guide Clearance - Intake - Service

0.025-0.099 mm

0.001-0.0039 in

Rocker Arms

  • Valve Rocker Arm Ratio

1.7:1

Valve Springs

  • Valve Spring Free Length

56.35 mm

2.218 in

  • Valve Spring Installed Height

45.92-46.69 mm

1.808-1.838 in

  • Valve Spring Load - Closed

381-419 N at 45.92 mm

86-94 lb at 1.808 in

  • Valve Spring Load - Open

964-1056 N at 33.99 mm

216-236 lb at 1.338 in