Re: Plasti-gauge

[rdh@sli.com (Robert D. Houk)]

   So, do you know what the hell the "Plasti-gauge" is?  I was flipping 
   through the Bently last night looking for critical dimensions when I saw 
   the reference to it.  How do you use it to measure bearing clearance?

Thought I'd CC the list on this one...

Plastigauge is this plastic "string" you buy. It is very precision made
string, and comes in a number of "calibrations".

It's used to measure bearing clearances, a very useful thing to know on
a nice freshly-blueprinted engine! (also useful on old worn engine to see
just how worn it is).

To use, you snip off a small piece (1/4 to 1/2 inch typical) and care-
fully lay in on the bearing surface(s) -- cam, crank, etc. -- and then
assemble the engine *DRY* (no oil, grease, "assembly pre lube", or any
of that stuff!), torqueing down everything to spec. You then take it
all apart again (e.g., pop the bearing caps) and look and see how much
the plastigauge string has been squashed (they give you this little
chart -- piece of paper with assorted "widths" lines), which in turn
tells you exactly how much clearance you have. I don't remember how
many sizes/etc, it comes in, but the resolution is easily .001 inch,
i.e., much smaller than "allowable variations" in bearing clearances.

The stuff costs a few bucks for enough to do a veritable fleet of en-
gines . . .

PlastiGauge and HeliCoils, perfect Xmas present for all those gearheads
on your shopping list!

					-RDH