Piston-To-Cylinder Bore Clearance

WARNING: This page is about a different car, the 2004 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.

Using a bore gauge, measure cylinder bore for wear, out-of-round and taper. The X axis is in the longitudinal direction of the engine.
Cylinder bore inner diameter

Fig 1: Cylinder Bore Specification Chart
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 2: Identifying Cylinder Bore Inner Diameter
Courtesy of NISSAN MOTOR CO., U.S.A.

If it exceeds the limit, rebore all cylinders. Replace cylinder block if necessary.
1. Out-of-round (Difference between, X - Y) :less than 0.015 mm (0.0006 in)
2. Taper (Difference between, C - A) :less than 0.015 mm (0.0006 in)
Fig 3: Measuring Cylinder Bore Inner Diameter
Courtesy of NISSAN MOTOR CO., U.S.A.
Check for scratches and seizure. If seizure is found, hone it.
- If both cylinder block and piston are replaced with new ones, select piston of the same grade number punched on cylinder block rear position. These numbers are punched in either Arabic or Roman numerals.
  
  Fig 4: Checking Scratches And Seizure
  Courtesy of NISSAN MOTOR CO., U.S.A.
Measure piston skirt diameter.
1. Piston diameter "A": Refer to PISTON, PISTON RING AND PISTON PIN .
2. Measuring point a (distance from the top): 41.0 mm (1.614 in)
Fig 5: Measuring Piston Skirt Diameter
Courtesy of NISSAN MOTOR CO., U.S.A.
Check that piston-to-bore clearance is within specification.
1. Piston-to-bore clearance at "B": 0.010 - 0.030 mm (0.0004 - 0.0012 in)
- The piston-to-bore clearance is measured at the B level in the cylinder as shown.
  
  Fig 6: Measuring Piston-To-Bore Clearance
  Courtesy of NISSAN MOTOR CO., U.S.A.
Determine piston oversize according to amount of cylinder wear.
- Oversize pistons are available for service.
- If oversize piston is used, use it for all cylinders with oversize piston ring. Refer to PISTON, PISTON RING AND PISTON PIN .
Cylinder bore size is determined by adding piston-to-bore clearance to piston diameter "A".
1. Rebored size calculation where,: D = A + B - C
  1. D: Bored diameter
  2. A: Piston diameter as measured
  3. B: Piston-to-bore clearance
  4. C: Honing allowance 0.02 mm (0.0008 in)
Install main bearing caps, and tighten to the specified torque. Otherwise, cylinder bores may be distorted after boring.
Cut cylinder bores.
- When any cylinder needs boring, all other cylinders must also be bored.
- Do not cut too much out of cylinder bore at a time. Cut only 0.05 mm (0.0020 in) or so in diameter at a time.
Hone cylinders to obtain specified piston-to-bore clearance.
Measure finished cylinder bore for out-of-round and taper.
- Measurement should be done after cylinder bore cools down.