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 bore and crankshaft bearing bore

NOTE:

Old bolts can be used for the measuring procedure.

1. Install the crankshaft bearing cap tie plate and tighten.
Fig 3: Measuring Bearing Bore Concentricity And Alignment Using Gauge Tool
Courtesy of GENERAL MOTORS COMPANY
2. Inspect the crankshaft main bearing bores. Use the EN-8087  gauge (1) to measure the bearing bore roundness tolerance. Refer to Engine Mechanical Specifications  to find the permitted values.
3. Replace the engine block and crankshaft bearing cap tie plate if the crankshaft bearing bores are out of specification.
Fig 4: Inspecting Cylinder Bore
Courtesy of GENERAL MOTORS COMPANY
4. Inspect the cylinder bores using the EN-8087  gauge (1). Inspect for the following items:
   • Wear
   • Taper
   • Runout
   • Ridging
5. Refer to Engine Mechanical Specifications  to find the permitted values.
6. If the cylinder bores are out of specification, replace the engine block.
7. Remove the crankshaft bearing cap tie plate.