Piston: Testing and Inspection

1. Piston and cylinder wall must be clean and dry. Piston diameter should be measured 90° to piston pin at size location shown in the figure. Cylinder bores should be measured halfway down the cylinder bore and transverse to the engine crankshaft center line. Correct piston to bore clearance must be established in order to assure quiet and economical operation. The standard value is 0.012 - 0.044 mm (0.0005 - 0.0017 inch)
2. Pistons and cylinder bores should be measured at normal room temperature, 21° C (70° F).