Boring Procedure

1. Before you start the honing or boring operation, measure all new pistons with a micrometer contacting at points exactly 90 degrees from the piston pin centerline. All measurements of the piston or the cylinder bore should be made with the components at normal room temperature.

Refer to Piston Selection and Engine Block Clean and Inspect to select the smallest oversize piston available for the cylinder. Piston dimensions vary slightly. Measure ALL pistons to be installed to find the closest match to the specific cylinder.

2. Before you use any type of boring bar, use a fine cut file on the top of the engine block cylinder head deck in order to remove any dirt, burrs or irregularities. Failure to check and/or correct the engine block cylinder head deck may result in a improperly installed boring bar. A improperly installed boring bar may result in the cylinder wall being bored at incorrect angle in relation to the crankshaft.
3. Follow the instructions furnished by the manufacturer regarding use of the boring equipment.
4. When boring cylinders, make sure all crankshaft bearing caps are in place and properly torqued. Failure to tighten the bearing caps to the proper torque may result in distortion of the cylinder bores during final assembly.

The crankshaft must be clear of the boring equipment cutter when boring each cylinder. Cover or protect the crankshaft journals and other internal components during boring or honing operations.

Refer to Crankshaft and Bearings Installation .

5. When taking the final cut with a boring equipment, leave 0.03 mm (0.001 in) diameter for the finish honing procedure. The final honing procedure fits the specific piston to the cylinder with the required clearance specifications. (Carefully perform the honing and boring operation in order to maintain the specified clearances between pistons, rings, and cylinder bores).

Honing Procedure

1. When honing the cylinders, follow the manufacturer's recommendations for equipment use, cleaning, and lubrication. Use only clean, sharp stones of the proper grade for the amount of material you remove. Dull, dirty stones cut unevenly and generate excessive heat. Do not hone to final clearance with a coarse or medium-grade stone. Leave sufficient metal so that all stone marks may be removed with fine-grade stones. Perform final honing with a fine-grade stone, honing the cylinder to the proper clearance.
2. During the honing operation, thoroughly clean the cylinder bore. Repeatedly check the cylinder bore for fit with the selected piston.

All measurements of the piston or the cylinder bore should be made with the components at normal room temperature.

3. When honing to eliminate taper in the cylinder, make full strokes the complete length of the bore. Repeatedly check the measurement at the top, the middle, and the bottom of the bore.
4. The finish marks should be clean but not sharp. The finish marks should be free from imbedded particles and torn or folded metal.
5. By measuring the selected piston at the sizing point and by adding the average of the clearance specification, you can determine the final cylinder honing dimension required.

Refer to Engine Mechanical Specifications .

6. When finished, the reconditioned cylinder bores should have less than or meet the specified out-of-round and taper requirements.
7. After final honing and before the piston is checked for fit, clean the cylinder bores with hot water and detergent. Scrub the bores with a stiff bristle brush and rinse the bores thoroughly with hot water. Do not allow any abrasive material to remain in the cylinder bores. This abrasive material may cause premature wear of the new piston rings and the cylinder bores. Abrasive material will also contaminate the engine oil and may cause premature wear of the bearings. After washing the cylinder bore, dry the bore with a clean rag.
8. Perform final measurements of the piston and the cylinder bore.
9. Permanently mark the top of the piston for the specific cylinder to which it has been fitted.
10. Apply clean engine oil to each cylinder bore in order to prevent rusting.