Main engine bearing clearance where and how to measure.

Main bearing
          It is measured between journal pin and top shell when the piston is at any convenient position.
Crosshead bearing
          It is measured between top shell and crosshead pin, piston should be at 45° aftrr TDC.
GUIDESHOE CLEARANCE
           Measured between GUIDESHOE and guide bar.
Bottom end bearing
            Measured between bottom shell and con rod. Piston should be at BDC.
   NOTE ALL CLEARANCE SHOULD BE BETWEEN 0.25-0.4MM

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