Page 1 of 1

Plastigauge: What it is--How to use it.

Posted: Wed Oct 06, 2010 8:10 am
by Bill E Bob
During my '57 rebuild, I had occasion to use plastigauge to determine proper bearing fit on the crankshaft.
What the pkg looks like:
Image
What the plastigauge looks like:
Image
What the plastigauge looks like on the bearing journal--do not lube the journal or bearing insert.
Image
Torque the bearings to spec with the plastigauge installed--do not turn the crankshaft.
Image
Carefully remove the bearing cap(s) and this is what you should see (only clearer):
Image
Next, use the package to measure the width of the compressed plastigauge.
Image
Remove the plastigauge from the bearing journal, lube the bearing and journal torque to specs and you're finished.
Image
Image
As for the flat tappet cam and concern with enough ZDDP, I added this to the oil.
Image