Quote:
Originally Posted by mkodama
-I’m measuring the crank main journal OD directly with my micrometers after checking micrometer with the included gauge pin.
-I’m measuring the bearing ID by checking micrometers with a gage pin, setting the micrometer to 68.000mm, then zeroing my bore gauge to the smallest value I can get between the micrometer, then measuring the smallest value inside the bearing. My bore gage is inch so my math is 68.000mm+(measurement*25.4).
- Oil clearance = bearing ID - journal OD
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Having never done an oil clearance measurement, I don't know how big a difference this would make, but I would suggest bypassing the gauge pins.
Just zero your bore gauge to wherever your micrometer ends up from measuring the journal OD. Then the bore gauge just reads the oil clearance directly. If I understand your procedure correctly, you're including two more measurements (the two involving gauge pins), and their associated errors, into your final calculation.
One would hope these errors don't overwhelm the actual measurement in which case you'd get the same result, but if the result turns out different - hopefully closer to spec - I'd go with that.