Honda CR-V: Block and Piston Inspection

1. Remove the crankshaft and pistons.

2. Check the piston for distortion or cracks.

3. Measure the piston diameter at a point 13 mm (0.5 in.) from the bottom of the skirt. There are two standard-size pistons (No Letter or A, and B). The letter is stamped on the top of the piston. Letters are also stamped on the block as cylinder bore sizes.

Piston Diameter

Standard (New):
No Letter (or A): 86.980-86.990 mm (3.4244-3.4248 in.)
B: 86.970-86.980 mm (3.4240-3.4244 in.)
Service Limit: No Letter (or A): 86.930 mm (3.4224 in.)
B: 86.920 mm (3.4220 in.)

Oversize Piston Diameter
0.25: 87.230-87.240 mm (3.4342-3.4346 in.)

4. Measure the wear and taper in direction X and Y at three levels inside each cylinder as shown. If the measurements in any cylinder are beyond the Oversize Bore Service Limit, replace the block. If the block is being rebored, refer to step 7 after reboring.

Cylinder Bore Size

Standard (New):
A or I: 87.010-87.020 mm (3.4256-3.4260 in.)
B or II: 87.000-87.010 mm (3.4252-3.4256 in.)
Service Limit: 87.070 mm (3.4279 in.)

Oversize Bore
0.25: 87.250-87.260 mm (3.4350-3.4354 in.)

Reboring Limit: 0.25 mm (0.01 in.) max.

Bore Taper

Limit: (Difference between first and third measurement) 0.05 mm (0.002 in.)

5. Scored or scratched cylinder bores must be honed.

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

Engine Block Warpage

Standard (New): 0.07 mm (0.003 in.) max.
Service Limit: 0.10 mm (0.004 in.)

7. Calculate the difference between the cylinder bore diameter and the 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): 0.020-0.040 mm (0.0008-0.0016 in.)
Service Limit: 0.05 mm (0.002 in.)

Cylinder Bore Honing

Only a scored or scratched cylinder bore must be honed.

1. Measure the cylinder bores.

If the block is to be reused, hone the cylinders, and remeasure the bores.

2. Hone the cylinder bores with honing oil and a fine (400 grit) stone in a 60 degree cross-hatch pattern (A). Use only a rigid hone with 400 grit or finer stone such as Sunnen, Ammco, or equivalent. Do not use stones that are worn or broken.

3. When honing is complete, thoroughly clean the engine block of all metal particles. Wash the cylinder bores with hot soapy water, then dry and oil them immediately to prevent rusting. Never use solvent, it will only redistribute the grit on the cylinder walls.

4. If scoring or scratches are still present in the cylinder bores after honing the engine block to the service limit, rebore the engine block. Some light vertical scoring and scratching is acceptable if it is not deep enough to catch your fingernail, and does not run the full length of the bore.

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