Ford Workshop Service and Repair Manuals

Piston: Specifications

Piston 

Diameter

Coded red 1....................................................................................................................................................... 90.177-90.197 mm (3.550-3.551 inch)
Coded blue 2................................................................................................................................................. 90.190-90.210 mm (3.5507-3.5515 inch)
Coded yellow 3............................................................................................................................................... 90.203-90.223 mm (3.513-3.5521 inch)

Piston-to-cylinder bore clearance............................................................................................................................ 0.012-0.0026 mm (0.0005-0.001 inch)
Piston ring end gap

Compression (top and bottom).................................................................................................................................. 0.23-0.49 mm (0.010-0.020 inch)
Oil ring (steel rail)..................................................................................................................................................... 0.05-0.66 mm (0.006-0.026 inch)

Piston ring groove width

Compression (top)................................................................................................................................................. 1.520-1.550 mm (0.060-0.610 inch)
Compression (bottom)......................................................................................................................................... 1.520-1.530 mm (0.060-0.0602 inch)
Oil ring................................................................................................................................................................ 6.996-7.224 mm (0.275-0.2844 inch)

Piston ring width

Compression.......................................................................................................................................................... 1.49-1.47 mm (0.0587-0.0579 inch)
Oil ring rail (2)........................................................................................ 0.473-0.447 mm (0.0186-0.0176 inch), 0.483 mm (0.0190 inch) max. at ID
Oil ring expander.................................................................................................................................................. 2.038-1.960 mm (0.080-0.077 inch)

Piston ring-to-groove clearance

Compression...................................................................................................................................................... 0.030-0.070 mm (0.0012-0.0028 inch)
Oil ring assembly.............................................................................................................................................. 0.046-0.196 mm (0.0018-0.0077 inch)

Piston pin

Bore diameter................................................................................................................................................ 22.0015-22.004 mm (0.866-0.8663 inch)
Pin diameter................................................................................................................................................................................. 22.0 mm (0.866 inch)
Pin length..................................................................................................................................................................................... 61.8 mm (2.433 inch)
Pin-to-piston fit................................................................................................................................................. 0.005-0.010 mm (0.0002-0.0004 inch)