Fitting Pistons & Rings: Notes
WARNING: This page is about a different car, the 1987 Chevrolet Sprint. However, it is still accessible from the selected car via links, so may be relevant.
- Check cylinder bores for scratches, roughness or ridges which indicate excessive wear. Using a cylinder bore gauge, measure cylinder bore in thrust and axial directions. Take measurements at 1.96" (50.0 mm) and again at 3.74" (95.0 mm) from top of cylinder bore.
- There are 3 numbers stamped on top of cylinder block, toward crankshaft pulley side. They identify cylinder bore diameter. The left number identifies cylinder No. 1, the center number identifies cylinder No. 2 and the number to the right identifies cylinder No. 3.
- Measure bore diameter, taper and out-of-round. If specifications are exceeded, rebore all cylinders to next oversize. Measure outer diameter of piston and determine piston-to-bore clearance. Measure piston .060" (15.0 mm) from bottom of piston skirt at a 90 degree angle to piston pin bore.
- Piston-to-bore clearance should be .0008-.0015" (.02-.04 mm). Numbers stamped on piston heads identify piston outer diameter. Pistons are stamped with either a "1" or "2". When installing standard pistons, ensure that piston is matched with cylinder. Oversize pistons are available in .010" (.25 mm) and .020" (.50 mm).
- Insert ring into top of cylinder bore and measure end gap using a feeler gauge. If end gap exceeds specifications, replace ring.
- Clean pistons. Insert new ring in piston groove. Use a feeler gauge to determine side clearance. If side clearance exceeds specifications, replace ring.