Yeh....how do you use plastigauge? What does it measure?

 

It is used to measures bearing clearances.

 

Yeh....I kinda knew that, but how do you use it?

 

1. Follow the directions to measure bearing oil clearence.
2. Check spec against the FS/helms manual

am i missing something?

 

Ive never dealt with it, seen it, nor know exatly what it is. I was curious to know what it is, and how you use it.

 

Plastigauge is a strip of squishable (for lack of a better word) material that you place between two parts when measuring very tight clearances. It comes in three different colors for measuring three different ranges of tight tolerences. For example, to measure the clearance between the big end of the rod and the rod journal bearing, you'd cut a small strip of plastigauge and place it lengthwise along the journal surface, like so...


Then you assemble the parts to clearance test, tighten until very snug (no need to completely torque the assembly down, especially in the case of rod bolts which aer not to be torqued more than once), and take the assembly apart again. The amount the plastigauge has widened when smashed between the parts indicates clearance, like this...


as checked by the supplied bar width rulers like this...


Make sense now?


[Modified by texan, 11:58 PM 2/2/2003]

 

here's a little info with a few pics http://www.c-speedracing.com/howto/b...s/bearings.php

 

Thanks for that quick tutorial Texan, y0 the man!

 

By the way, the other side of the plastiguage wrapper reads in mm's. Plastiguage is my favorite tool for building motors.

 

Thank you, exactly what I was looking for.

 

so do you have to do one at a time?
or can you do all the main bearings and all the connection rod bearings at the same time?