K. CRANKSHAFT : 1. Carry out visual inspection of the crankshaft for the following : Overheating of journals – indicated by bluish • brown color. Scoring marks on journals • Using magnetic crack detector, check for • cracks. 2. Place crankshaft on V-block, and check for run out on 1st and 5th bearing journals. 3. If the run out exceeds permissible limits, using a press carefully straighten the crankshaft in cold condition. 4. Check lateral and radial run out of flywheel mounting flange/ 5. Check dimensions of crankshaft main bearing and crank pin journals. (Grind if necessary, crankshaft main bearing and crank pin journals to the next under size.) If the 4th main bearing has to be ground, then 6. grind it to next oversize. 7. Always re-chamfer oil holes on journals to avoid scoring of new bearing shells. 8. Clean oil holes with wire brush. 9. Finish journals by covering with 320 grit lapping cloth of suitable width. Re-check main bearing, crank pin journal 10. dimensions and run out of crank shaft. Clean crankshaft with suitable cleansing agent. 11. MAINTENANCE LIMIT (REVOTRON 1.2L) IN MM Connecting rod small end bush inside diameter (finished after installation) 18.007 / 18.020 Maximum permissible out of parallelism (bend) between connecting rod small end and big end parent bores. 0.015 Center to center distance between connecting rod small end and big end parent bores 138.8 ± 0.03 Maximum permissible twist of connecting rod 0.030 Connecting rod big end parent bore diameter 45.000 / 45.016 Big end parent bore and cylindricity 0.01 Bearing shell to be selected such that clearance is maintained as 0.027 - 0.066 Crush height of connecting rod big end bearing shells 0.025 - 0.055 Connecting rod big end axial play 0.05 - 0.35 NOTE Connecting rod bearing shells are precision finished and should not be bored or scraped. NOTE Maintain correct fillet radii for journals. Width of journals should not increase during grinding. NOTE After grinding, re-check crankshaft for cracks and balance. Crankshaft must always be stored in vertical position. All machined surfaces should be greased. CRANK BORE DIAMETER (MM) M 52.000 - 52.009 N 52.010 - 52.019 1.2L REVOTRON CNG PHASE-2 ENGINE 73
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