Cylinder Bore and Piston-Sizing

Fig. 3

The cylinder walls should be checked for out-of-round and taper with recommended tool C-119 or equivalent (Fig. 3). The cylinder bore out-of-round and cylinder bore taper must within service limits. Refer to General Specifications. Engine 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 operations should be closely coordinated with the fitting of pistons and rings in order to maintain specified clearances. Refer to Honing Cylinder Bores in Standard Service Procedures. Cylinder Bore Honing
Measure the cylinder bore at three levels in directions A and B (Fig. 3). 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 General Specifications for cylinder block specifications. Engine Specifications

SIZING PISTONS





Fig. 4

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 (Fig. 4). Cylinder bores should be measured halfway down the cylinder bore and transverse to the engine crankshaft center line shown in (Fig. 3). Correct piston to bore clearance must be established in order to assure quiet and economical operation. Refer to General Specifications for cylinder block and piston specifications. Engine Specifications
DaimlerChrysler 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).