Piston Protrusion Check

For information on Ford Color Coded Illustrations, refer to OEM COLOR CODING

Special Tool(s) / General Equipment 

Check 

1. Verify that the cylinder block deck surface and the pistons are clean.
2. The piston protrusion is measured in-line front and rear avoiding raised or etched marking.

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3. NOTE: Use a commercially available deck bridge such as the Proform® 66797 Magnetic Deck Bridge or equivalent.
   • Using the dial indicator and a commercially available deck bridge, position at one of the points on the cylinder block deck surface. Use the General Equipment: Dial Indicator
   • Zero the dial indictor on the cylinder block deck surface.

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4. NOTE: Only rotate the crankshaft clockwise.
   NOTE: The piston must remain at TDC or an inconsistent reading will result.
   • Position the dial indicator and a commercially available deck bridge, over the piston. Use the General Equipment: Dial Indicator
   • Rotate the crankshaft until the piston is at TDC. Use the General Equipment: Dial Indicator
   • Record the reading.

   Courtesy of FORD MOTOR COMPANY

5. • Move the dial indicator and the commercially available deck bridge, on the cylinder block deck surface at the opposite position. Use the General Equipment: Dial Indicator
   • Zero the dial indictor on the cylinder block deck surface.

   Courtesy of FORD MOTOR COMPANY

6. • Move the dial indicator and the commercially available deck bridge, onto the piston at the opposite position. Use the General Equipment: Dial Indicator
   • Record the reading.

   Courtesy of FORD MOTOR COMPANY

7. Average the readings and record.
8. Repeat on the remaining pistons.
9. Determine the cylinder head gasket thickness. Refer to: Specifications in the appropriate engine article.