Important:
• | The coating on the piston allows for an interference fit between the cylinder and the bore. The piston diameter can NOT be measured accurately because the piston coating is not a consistent thickness. Do NOT measure the piston diameter. |
To select the correct piston for installation, the cylinder bore must be measured. If the cylinder bore diameter is within service specifications, install the original piston/connecting rod assembly or a new, standard size piston/connecting rod assembly. A piston/connecting rod assembly may be used again if, after cleaning and inspection, the piston is not damaged. If the cylinder bore is NOT within specifications, the cylinder must be resized to accept a new, oversized piston. |
• | If you do not inspect the cylinder block, the boring bar may be tilted. This may result in incorrect rebored cylinder wall to crankshaft angle. |
• | Tighten the bearing caps to the proper torque in order to avoid distortion of the bores in the final assembly. |
• | The crankshaft must be removed prior to cylinder boring. |
Important: Always remove all bearings and components from the engine block before cleaning, boring, or honing the engine block.
• | 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 a final grade with a coarse or medium-grade stone. |
• | Leave sufficient metal so that all stone marks may be removed with fine grade stones. |
• | The rehoned surface finish should be 0.25-0.50 micrometer (10-20 microinch). |
• | Perform final honing with a fine-grade stone and hone the cylinder in a cross-hatch pattern at 20 to 30 degrees to obtain the proper clearance. |
• | Repeatedly inspect the cylinder bore for fit with the selected oversized piston. |
• | All measurements of the cylinder bore should be made with the components at normal room temperature. |
• | The finish marks should be clean but not sharp. |
• | The finish marks should be free from embedded particles and torn or folded metal. |
5.1. | 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. |
• | Abrasive material may cause premature wear of new piston rings and cylinder bores. |
• | Abrasive material will contaminate the engine oil and may cause premature wear of the bearings. |
5.2. | After washing the cylinder bore, dry the bore with a clean shop towel. |