ZEST BOLT Service Manual

ENGINE 1.3 QUADRAJET (75PS) 55 Above is an example of identifying the main journal and crankpin grade referring to an engine with nominal diameter main journals (51.000 mm). 1) Crankpin alphabetical identification code - BBBB (the same for all bearings): the first letter from the left refers to the first timing side bearing. 2) Main journal alphabetical identification code - AAAAA (the same for all bearings): the first letter from the left refers to the first timing side bearing. 3) Alphabetical identification code for thrust washers - R. Only use the alphabetical codes for references 1, 2 and 3 in the diagram, all the other codes on the counter-weight should not be used. For the identification of the main journal grade, refer to the alphabetical code 2 shown in the diagram. In the case of the diagram, for example, the letter code AAAAA (Grade A - Normal) indicates that all five bearings are prepared for the fitting of half- bearings with a Red coloured paint mark on the edge; as a result, specific half-bearings should be identified for different alphabetical codes (bearing grade). The letter code stamped on the timing side counter- weight is required for selecting the grade. Normal grades are usually used on new engines with undersizes only used in exceptional cases. ALLOCATION OF HALF-BEARINGS TO MAIN JOURNALS: Having defined the grade for each crankshaft bearing (to which a specific diameter corresponds according to the grade), it is necessary to select the p air of Main journal grade Diameter Paint Mark grade A (normal) 51.000 ~ 50.994 mm RED paint mark grade B (normal), 50.994 ~ 50.988 mm BLUE paint mark grade C (normal), 50.988 ~ 50.982 mm YELLOWpaint mark grade AM (0.127 undersize) 50.873 ~ 50.867mm BROWN paint mark grade BM (0.127 undersize) 50.867 ~ 50.861mm, GREEN paint mark grade CM (0.127 undersize) 50.861 ~ 50.855mm BLACK paint mark Minimum Maximum 0.025 mm 0.052 mm bearings which are the same colou.r This is designed to guarantee the optimum operational clearances for all the bearings. Lastly, we wish to point out that, generally , the clearance between the main journal and the half- bearing, obtained through the selection method indicated above, should be within the following values: