Cylinder Bore and Piston-Sizing

Fig. 14

The cylinder walls should be checked for out-of-round and taper with Tool C-119 (Fig. 14). Refer to Engine Specifications for cylinder bore out-of-round and cylinder bore taper specifications. If the cylinder walls are badly scuffed or scored, the cylinder block should be rebored and honed, and new pistons and rings fitted. Whatever type of boring equipment is used, boring and honing operation should be closely coordinated with the fitting of pistons and rings in order that specified clearances may be maintained. Refer to Honing Cylinder Bores outlined in the Standard Service Procedures for specification and procedures.
Measure the cylinder bore at three levels in directions A and B. Top measurement should be 10 mm (3/8 inch) down and bottom measurement should be 10 mm (3/8 inch) up from bottom of bore. Refer to Engine Specifications.

SIZING PISTONS





Fig. 15

Piston and cylinder wall must be clean and dry. Piston diameter should be measured 90 degrees to piston pin about 17.5 mm (11/16 inch) from the bottom of the skirt as shown in image. Cylinder bores should be measured halfway down the cylinder bore and transverse to the engine crankshaft center line shown in (Fig. 14). Refer to Engine Specifications. Correct piston to bore clearance must be established in order to assure quiet and economical operation.
Daimler Chrysler engines use pistons designed specifically for each engine model. Clearance and sizing locations vary with respect to engine model.

NOTE: Pistons and cylinder bores should be measured at normal room temperature, 21°C (70°F).