Piston - Selection

WARNING: This page is about a different car, the 2004 Lincoln Navigator and 2004 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: The cylinder bore must be within the specifications for taper and out-of-round before fitting a piston.

Select a piston size based on the cylinder bore.

Fig 1: Identifying Cylinder Diameter Bore Measuring Directions
Courtesy of FORD MOTOR CO.

NOTE: For precision fit, new pistons are divided into three categories within each size range based on their relative position within the range. The specific grade size is marked on each piston.

Fig 2: Identifying Grade Size Of Piston

Courtesy of FORD MOTOR CO.

Choose the piston with the correct grade size.
- Refer to the appropriate article in ENGINES for the procedure.