Fitting Pistons

WARNING: This page is about a different car, the 2002 Pontiac Firebird and 2002 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Replace the pistons and the pins that are damaged or show signs of excessive wear. The piston and the pin are a matched set. If service is required, replace the piston and the pin as an assembly.

NOTE: DO NOT wire brush any part of the piston.

Clean the varnish from the piston and the pin with cleaning solvent. Dry the piston and the pin with compressed air. Clean the piston ring grooves with a suitable ring groove cleaning tool. Clean the oil lubrication holes and slots.
Inspect the piston and the pin for the following:
- Cracks in the piston ring lands, the piston skirt, or the pin bosses.
- Piston ring grooves for nicks, burrs, or warpage which may cause the piston ring to bind. MINOR imperfections may be removed from the piston with a fine file.
- Scuffed or damaged skirts.
- Eroded areas at the top of the piston.
- Scoring to the piston pin bore or the piston pin.
To determine piston pin-to-bore clearance, use a micrometer and measure the piston pin. To determine piston pin-to-bore clearance, use an inside micrometer and measure the piston pin bore. To determine the proper piston pin-to-bore clearance, subtract the piston pin diameter from the piston pin bore diameter. See PISTONS, PINS & RINGS SPECIFICATIONS table.
Measure the piston for out-of-round. See PISTONS, PINS & RINGS SPECIFICATIONS table.