Piston Diameter

WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Typical piston shown.

NOTE: When considering installing a new piston, check the cylinder bore out-of-round specifications, cylinder boring may be necessary. Cylinder bore reconditioning will require oversize service pistons.

Use a 75-100 mm (3-4 in) micrometer to measure the piston skirt. Verify piston size by measuring the skirt diameter.
- Measure 15.5 mm (0.61 in) from the bottom, at 90 degrees to the piston pin, at room temperature of 19-21°C (66-70°F).
- Install a new piston if not within specification. For additional information, refer to SPECIFICATIONS .
  
  Fig 1: Measuring Piston Skirt Using Micrometer
  Courtesy of FORD MOTOR CO.