SAFARI

46 4 DLT ENGINE M easure pre tension of main bearing shell with a feeler gauge after loosening main bearing cap mounting bolt on opposite side of bearing shell lug. (This is to be done on a flat surface plate as it cannot be measured on engine cylinder block because the main bearing caps are guided) MAIN BEARING SHELLS ARE PRECISION FINISHED AND SHOULD NOT BE BORED OR SCRAPED. S elect new pair of thrust washer according to crank shaft 4th main journal width. CYLINDER BORES C lean cylinder bores thoroughly. C heck cylinder bore dimension, taper and ovality. Refer Figures. 74 & 75 I f taper and ovality is found to exceed specified limit or bore is excessively worn out machine cylinder bore to next over size. S election of size to which bore should be machined should be choosen as per following parameters : - Bore diameter of worn out cylinder bore - Size of next piston available - Recommended clearance between piston and bore - Required bore diameter M achine all bores leaving 0.050 to 0.070 mm stock for honing. IT IS VERY IMPORTANT THAT AXIS OF CYLINDER BORESAREPARALLELTOEACHOTHERANDARE AT RIGHT ANGLE TO AXIS OF CRANK SHAFT. T herefore we recommend use of pillar type boring and honing machines. C lean cylinder bores, bearing surface and oil passages in crank case thoroughly. C heck water jackets and oil passages for leakages/ cracks at air pressure of 5 bar under water. A pply grease tomachined surfaces especially if engine assembly is not be taken up immediately. Fig. 74 Fig. 75