Block and Piston Inspection: Inspection

How to use this manual .

1. Engine Block Warpage - Inspect

   Preconditions 

   • Engine Block Removed

   Courtesy of HONDA, U.S.A., INC.

   Courtesy of HONDA, U.S.A., INC.

   Procedure/Specifications 

   • Check the top of the block for warpage. Measure along the edges and across the center as shown.

   Tool Details 

   Name
   a	Precision Straight Edge (Commercially Available)
   b	Feeler Gauge

   Specifications 

   Standard Value (New)
   0.07 mm (0.002 in) max.

   Result 

   • If the measurement is not within specifications, replace the engine block .
2. Cylinder Bore - Inspect

   Preconditions 

   • Engine Block Removed

   Figure 1 

   Courtesy of HONDA, U.S.A., INC.

   Figure 2 

   Courtesy of HONDA, U.S.A., INC.

   Procedure/Specifications 

   1. Measure the wear and taper in direction Y and X at three levels inside each cylinder as shown. (Figure 1 and 2)

   Measurement Position (Figure 1) 

   Standard Value
   a	First Measurement	10 mm (0.39 in)
   b	Second Measurement	50 mm (1.97 in)
   c	Third Measurement	130 mm (5.12 in)

   Specifications (Cylinder Bore Size) (Figure 2) 

   Standard Value (New)		Service Limit
   X	89.000-89.020 mm (3.50393-3.50472 in)	89.065 mm (3.50649 in)
   Y	89.000-89.015 mm (3.50393-3.50452 in)

   Oversize Bore 

   Standard Value
   0.25	86.250-86.265 mm (3.39566-3.39625 in)

   Specifications (Bore Taper) 

   Service Limit
   (Difference between first and third measurement) 0.025 mm (0.00098 in)

   2. Hone any cored or scratched cylinder bores - Refer to: Block and Piston Inspection ()  or Cylinder Bore Honing ()  if needed. If the engine block is being rebored, check the piston-to- cylinder bore clearance.

   Reboring Limit 

   Standard Value
   0.25 mm (0.0098 in) max.

   Result 

   • If measurements in any cylinder are beyond the oversize bore service limit, replace the engine block .
3. Piston Skirt Diameter - Inspect

   Preconditions 

   • Piston Removed

   Figure 1 

   Courtesy of HONDA, U.S.A., INC.

   Figure 2 

   Courtesy of HONDA, U.S.A., INC.

   Procedure/Specifications 

   1. Check the pistons for distortion or cracks.

   Specifications 

   Object	Specification
   Piston	No distortion or cracks

   2. Measure the piston skirt diameter at a point (a) from the bottom of the skirt. (Figure 1)

   Measurement Position (Figure 1) 

   Standard Value
   a	16 mm (0.63 in)

   Specifications (Figure 1) 

   Service Limit
   b	88.950 mm (3.50196 in)

   Tool Details (Figure 2) 

   Name
   c	Micrometer

   Result 

   • If the measurement is not within specifications, replace the piston.
4. Piston-to-Cylinder Bore Clearance - Inspect

   Preconditions 

   • Piston Removed

   Courtesy of HONDA, U.S.A., INC.

   Procedure/Specifications 

   • Calculate the difference between the cylinder bore diameter and the piston diameter.

   Specifications 

   Service Limit
   a	0.08 mm (0.0031 in)

   Result 

   • If the measurement is not within specifications, the clearance is near, or exceeds the service limit, inspect the piston and the cylinder bore for excessive wear.