FIG. 80

upward and in such a manner that the left end does not touch the bench, and let it cool.
 

Section 2:

Alignment Of The Crankshaft

1. If you are installing a new or rebuilt crankshaft, or are installing new engine cases, it is advisable to check the end play and alignment of the crankshaft.

2. The big end of the connecting rod has a great deal of side clearance on the crank pin to allow for sufficient lubrication at all R.P.M.'s. This presents the need for:

(a) The crankshaft end play to be correct. If the play is too little, it could cause side loading of the main bearings, resulting in their destruction. If the play is too great, it will allow the crankshaft to move back and forth far enough that the crankshaft flywheels could strike the connecting rod.

FIG. 81

(b) The crankshaft is to be aligned so that the connecting rod is centered between the flywheels. If it is not centered properly, the connecting rod could be subjected to side loading, or, worse yet, breakage due to striking the flywheels.

3. To check the crankshaft end play and alignment, it will be necessary to mount the crankshaft in the cases and measure the amount of end play by sliding the crankshaft back and forth f rom right to left, and measuring its movement. However, this is impossible with the lefthand main bearing installed, as it is a slight press fit on the shaft and does not allow the crank to be slid back and forth easily.

4. It is therefore necessary to make a special or "dummy" main bearing for temporary use while checking the crankshaft. This dummy bearing will allow the crankshaft to be easily slid back and forth to check the end play.



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