Measuring Procedure

Engine Block Flatness Inspection

Fig 1: Inspecting Engine Block For Distortion Using Straight Edge
Courtesy of GENERAL MOTORS COMPANY
1. Inspect the engine block as shown for distortion. Use a straightedge (1).
Fig 2: Inspecting Engine Block For Deflection Using Straight Edge
Courtesy of GENERAL MOTORS COMPANY
2. Inspect the engine block as shown for deflection. Use a straightedge (1).

Cylinder Sleeve Diameter Inspection

Fig 3: Inspecting Cylinder Bore
Courtesy of GENERAL MOTORS COMPANY
NOTE:

If the cylinder sleeve measurements are not within the recommended limits, ream the cylinder bores with the recommended oversize. Refer to Engine Mechanical Specifications .

1. Inspect the cylinder bores using the EN-8087  gauge (1). Inspect for the following items:
   • Wear of cylinder sleeve
   • Cylinder sleeve diameter
   • Tapering of cylinder sleeve
   • Oval status of cylinder sleeve

     Refer to Engine Mechanical Specifications  for the recommended limits.

Bearing Bore Diameter In Cylinder Block Inspection

Fig 4: Crankshaft, Lower Crankcase, Locating Pins And Bolts
Courtesy of GENERAL MOTORS COMPANY
1. Install the 10 lower crankcase locating pin, if they was removed.
2. Install the crankshaft to the engine block (4).
3. Install the lower crankcase (1).
4. Loosely install the 10 main bearing bolts M10 (2).
5. Loosely install the 11 lower crankcase bolts M8 (3).
Fig 5: Main Bearing And Lower Crankcase Bolt Tightening Sequence
Courtesy of GENERAL MOTORS COMPANY
CAUTION:

Refer to Fastener Caution .

CAUTION:

Refer to Torque-to-Yield Fastener Caution .

6. Tighten the 10 main bearing bolts.
   1. Tighten the bolts (1-10) a first pass in sequence shown to 50 N.m (37 lb ft).
   2. Tighten the bolts (1-10) a second pass in sequence shown an additional to 90 degrees, using the EN-45059  meter.
   3. Tighten the bolts (1-10) a final pass in sequence shown an additional to 90 degrees, using the EN-45059  meter.
7. Tighten the 11 lower crankcase bolts (11-21) in sequence shown to 34 N.m (25 lb ft).
Fig 6: Measuring Bearing Bore Concentricity And Alignment Using Gauge Tool
Courtesy of GENERAL MOTORS COMPANY
8. Inspect the bearing bore diameter in cylinder block using the EN-8087  gauge (1). Refer to Engine Mechanical Specifications  for the recommended limits.
Fig 7: Crankshaft, Lower Crankcase, Locating Pins And Bolts
Courtesy of GENERAL MOTORS COMPANY
9. Remove the 11 lower crankcase bolts (3).
10. Remove the 10 main bearing bolts (2).
11. Remove the lower crankcase (1) from the engine block (4).
12. Remove the 10 lower crankcase locating pin (5), if they was removed.