Cylinder Bore Diameter Gauge

If installing new rings in a used cylinder that has not been refinished, remove the cylinder wall glaze using only spring-loaded Engine Cylinder Hone Set 303-S084 (T73L-6011-A). Remove only if there is no visible sign of cross-hatch markings on the cylinder walls. (Refer to Cylinder Walls, Refinishing.) Always clean the cylinder bore thoroughly with detergent and water solution.

1. NOTE: After any refinishing operation, allow cylinder bore to cool. Make sure piston and bore are clean and dry before checking piston fit.

Calculate size of piston to be used by taking a cylinder bore check.
2. Select proper size piston to provide desired clearance. Measure piston diameter in-line with centerline of piston pin and at 90 degrees to piston pin axis.
3. Make sure piston and cylinder block are at room temperature, 21°C (70°F).
Measure the piston diameter to obtain the specified clearance. It may be necessary periodically to use another piston (within the same grade size) that is either slightly larger or smaller to achieve the specified clearance.