Piston Selection
WARNING: This page is about a different car, the 2002 Pontiac Sunfire and 2002 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
Important: Measurements of all components should be taken with the components at normal room temperature.
For proper piston fit, the engine block cylinder bores must not have excessive wear or taper.
A used piston and pin set may be reinstalled if, after cleaning and inspection, they are within specifications.
- Inspect the engine block cylinder bore. Refer to Engine Block - Cleaning & Inspection .
- Inspect the piston and the piston pin. Refer to Piston, Connecting Rod & Bearings - Cleaning & Inspection .
- Using the J 8087 measure the cylinder bore diameter. Measure at a point 64 mm (2.5 in) from the top of the cylinder bore.
- Measure the J 8087 with a micrometer and record the reading.
- With a micrometer or caliper at a right angle to the piston, measure the piston 42 mm (1.68 in) from the top of the piston.
- Subtract the piston diameter from the cylinder bore diameter in order to determine piston-to-bore clearance.
- For proper piston-to-bore clearance, refer to Engine Mechanical Specifications .
- If the proper clearance cannot be obtained, select another piston and measure for the clearances.
- If the proper fit cannot be obtained, hone the cylinder bore or replace the cylinder block.
- When the piston-to-cylinder bore clearance is within specifications, mark the top of the piston using a permanent marker for installation to the proper cylinder. Refer to Separating Parts .