SENR9977 53 Testing and Adjusting Section The correct piston height must be maintained in order to ensure that the engine conforms to the standards for emissions. i01897548 Flywheel - Inspect Note: The top of the piston should not be machined. If the original piston is installed, be sure that the original piston is assembled to the correct connecting rod and installed in the original cylinder. Alignment of the Flywheel Face Six grades of length of connecting rods determine the piston height above the cylinder block. The grade of length of a connecting rod is identified by a letter or a color. The letter or the color is marked on the side of the connecting rod.
Refer to Testing and Adjusting, “Connecting Rod - Inspect” and Specifications, “Connecting Rod” for additional information. g00987751 Illustration 60 1. Install the dial indicator. Refer to Illustration 60. 2. Set the pointer of the dial indicator to 0 mm (0 inch). 3. Turn the flywheel. Read the dial indicator for every 90 degrees. g00983585 Illustration 59 (1) Dial gauge (2) Dial gauge holder Note: During the check, keep the crankshaft pressed toward the front of the engine in order to remove any end clearance. 1. Use the dial gauge (1) and the dial gauge holder (2) in order to measure the piston height above the cylinder block. Use the cylinder block face to zero the dial gauge (1). 4.
Calculate the difference between the lowest measurement and the highest measurement of the four locations. This difference must not be greater than 0.03 mm (0.001 inch) for every 25 mm (1.0 inch) of the radius of the flywheel. The radius of the flywheel is measured from the axis of the crankshaft to the contact point of the dial indicator. 2. Rotate the crankshaft until the piston is at the approximate top center. 3. Position the dial gauge holder (2) and the dial gauge (1) in order to measure the piston height above the cylinder block. Slowly rotate the crankshaft in order to determine when the piston is at the highest position. Record this dimension.
Compare this dimension with the dimensions that are given in Specifications, “Piston and Rings”.