Bearing clearance

[Cobra52898]

Does anyone use Plasti-Gauge for checking bearing clearance on the main and rod bearings? If so is it acceptable to check the clearance at only one location per bearing or should the readings be taken at several locations around each bearing journal? Back in my Navy days when checking bearing clearances on equipment it was a standard practice to check the clearance in 3 locations around the journal 12:00, 4:00 and 8:00 o'clock.

 

[CJK440]

Plastigauge is considered a hack tool for many but I have used it on every engine I have built in some cases as the only clearance check in low po apps, and in others as a sanity check after mic'ing the bearings/journal.

Check it 90 degrees from the cap parting line for two reasons.

First, bearings usually have some eccentricity whereas the clearance is tighter at that point.

Second, is anything off of 90 degrees and you risk smearing the guage when the cap is installed/removed. 90 degrees is a nice perpendicular squish.