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Block and Piston Inspection

  1. Remove the piston from the engine block (see CRANKSHAFT AND PISTON REMOVAL  ).
  2. Check the piston for distortion or cracks.
  3. Measure the piston diameter at a point 16.0 mm (0.63 in.) from the bottom of the skirt.

    Piston Diameter 

    • Standard (New): 88.975-88.985 mm (3.5029-3.5033 in.) 
    • Service Limit: 88.965 mm (3.5026 in.) 

    Oversize Piston Diameter 

    • 0.25: 89.225-89.235 mm (3.5128-3.5132 in.) 
    Fig 1: Measuring Piston Diameter From Bottom Of Skirt
    G03639461Courtesy of AMERICAN HONDA MOTOR CO., INC.
  4. Measure wear and taper in direction X and Y at three levels in each cylinder as shown in Fig 2 . If measurements in any cylinder are beyond the oversize bore service limit, replace the engine block. If the engine block has to be rebored, refer to step  7 after reboring.

    Cylinder Bore Size 

    • Standard (New): 89.000-89.015 mm (3.5039-3.5045 in.) 
    • Service Limit: 89.065 mm (3.5065 in.) 

    Oversize 

    • 0.25: 89.250-89.265 mm (3.5138-3.5144 in.) 
    • Reboring Limit: 0.25 mm (0.01 in.) 

    Bore Taper 

    • Limit: (Difference between first and third measurement) 0.05 mm (0.002 in.) 
    Fig 2: Measuring Wear And Taper In Direction X And Y
    G03639462Courtesy of AMERICAN HONDA MOTOR CO., INC.
  5. Hone any scored or scratched cylinder bores.
  6. Check the top of the engine block for warpage. Measure along the edges and across the center as shown in Fig 3 .

    Engine Block Warpage 

    • Standard (New): 0.07 mm (0.003 in.) max. 
    • Service Limit: 0.10 mm (0.004 in.) 
    Fig 3: Measuring Along Edges And Across Center
    G03639463Courtesy of AMERICAN HONDA MOTOR CO., INC.
  7. Calculate the difference between cylinder bore diameter and piston diameter. If the clearance is near or exceeds the service limit, inspect the piston and cylinder bore for excessive wear.

    Piston-to-Cylinder Bore Clearance 

    • Standard (New): 0.015-0.040 mm (0.0006-0.0016 in.) 
    • Service Limit: 0.08 mm (0.003 in.) 
    Fig 4: Calculating Difference Between Cylinder Bore Diameter And Piston Diameter
    G03639464Courtesy of AMERICAN HONDA MOTOR CO., INC.