GM Service Manual Online
For 1990-2009 cars only

Application

Specification

Metric

English

General Data

  • Engine Type

60° V-6

  • Displacement

3.1L

191 cu in

  • RPO (VIN Code)

LG8 (J)

  • Bore

89 mm

3.50 in

  • Stroke

84 mm

3.31 in

  • Compression Ratio

9.5:1

  • Firing Order

1-2-3-4-5-6

  • Oil Pressure

103 kPa

15 psi @ 1100 RPM

Cylinder Bore

  • Diameter

89.016-89.034 mm

3.5046-3.5053 in

  • Out Of Round Maximum

0.014 mm

0.0005 in

  • Taper -- Thrust Side Maximum

0.020 mm

0.0008 in

Piston

  • Diameter-Gaged on the skirt 12 mm below the centerline of the piston pin bore

88.974-89.001 mm

3.5029-3.5040 in

  • Clearance

0.032-0.068 mm

0.0013-0.0027 in

  • Pin Bore

23.006-23.013 mm

0.9057-0.9060 in

Piston Ring

  • Top Groove Side Clearance

0.05-0.085 mm

0.002-0.0033 in

  • Second Groove Side Clearance

0.05-0.09 mm

0.002-0.0035 in

  • Top Ring Gap

0.15-0.36 mm

0.006-0.014 in

  • Second Ring Gap

0.5-0.71 mm

0.0197-0.0280 in

  • Groove Clearance

0.20 mm

0.008 in in

  • Gap with segment at 89.0 mm

0.25-1.27 mm

0.0098-0.05 in

Piston Pin

  • Diameter

22.9915-22.9964 mm

0.9052-0.9054 in

  • Clearance In Piston

0.0096-0.0215 mm

0.0004-0.0008 in

  • Fit In Rod

0.0165-0.0464 mm

0.0006-0.0018 in

Crankshaft

  • Main Journal Diameter

67.239-67.257 mm

2.6473-2.6483 in

  • Main Journal Taper

0.005 mm

0.0002 in

  • Out Of Round

0.005 mm

0.0002 in

  • Flange Runout-Max

0.04 mm

0.0016 in

  • Cylinder Block Main Bearing Bore Diameter

72.155-72.168 mm

2.8407-2.8412 in

  • Crankshaft Main Bearing Inside Diameter

67.289-67.316 mm

2.6492-2.6502 in

  • Main Bearing Clearance

0.019-0.064 mm

0.0008-0.0025 in

  • Main Thrust Bearing Clearance

0.032-0.077 mm

0.0012-0.0030 in

  • Crankshaft End Play

0.060-0.210 mm

0.0024-0.0083 in

  • Crankshaft Flange Runout-Max

0.04 mm

0.0016 in

Connecting Rod

  • Connecting Rod Bearing Journal Diameter

50.768-50.784 mm

1.9987-1.9994 in

  • Connecting Rod Bearing Journal Taper

0.005 mm

0.0002 in

  • Connecting Rod Bearing Journal Out Of Round

0.005 mm

0.0002 in

  • Connecting Rod Bearing Bore Diameter

53.962-53.984 mm

2.124-2.125 in

  • Connecting Rod Inside Bearing Diameter

50.812-50.850 mm

2.000-2.002 in

  • Connecting Rod Bearing Journal Clearance

0.018-0.062 mm

0.0007-0.0024 in

  • Connecting Rod Side Clearance

0.18-0.44 mm

0.007-0.017 in

Camshaft

  • Lobe Lift (Intake and Exhaust)

6.9263 mm

0.2727 in

  • Journal Diameter

47.45-47.48 mm

1.868-1.869 in

  • Camshaft Bearing Bore Diameter-Front and Rear

51.03-51.08 mm

2.009-2.011 in

  • Camshaft Bearing Bore Diameter-Middle #2 and #3

50.77-50.82 mm

1.999-2.001 in

  • Camshaft Bearing Inside Diameter

47.523-47.549 mm

1.871-1.872 in

  • Journal Clearance

0.026-0.101 mm

0.001-0.0039 in

  • Journal Runout-Max

0.025 mm

0.001 in

Valve System

  • Roller Lifter

Hydraulic

  • Rocker Arm Ratio

1.60:1

  • Valve Face Angle

45°

  • Seat Angle

45°

  • Valve Seat Runout

0.025 mm

0.001 in

  • Seat Width-Intake

1.55-1.80 mm

0.061-0.071 in

  • Seat Width-Exhaust

1.70-2.0 mm

0.067-0.079 in

  • Valve Margin - Minimum Intake

2.10 mm

0.083 in

  • Valve Margin - Minimum Exhaust

2.70 mm

0.106 in

  • Valve Stem Clearance

0.026-0.068 mm

0.0010-0.0027 in

Valve Spring

  • Valve Springs Free Length

48.5 mm

1.89 in

  • Valve Springs Load (Closed)

320 N @ 43.2 mm

75 lb @ 1.701 in

  • Valve Springs Load (Open)

1036 N @ 32 mm

230 lb @ 1.260 in

  • Installed Height Intake-Exhaust

43.2 mm

1.701 in

  • Approx. # or coils

6.55

Oil Pump

  • Gear Lash

0.094-0.195 mm

0.0037-0.0077 in

  • Gear Pocket Depth

30.52-30.58 mm

1.202-1.204 in

  • Gear Pocket Diameter

38.176-38.226 mm

1.503-1.505 in

Gear

  • Length

30.45-30.48 mm

1.199-1.200 in

  • Diameter

38.05-38.10 mm

1.498-1.500 in

  • Side Clearance

0.038-0.088 mm

0.001-0.003 in

  • End Clearance

0.040-0.125 mm

0.002-0.005 in

  • Valve to Bore Clearance

0.038-0.089 mm

0.0015-0.0035 in