Subject: Bore gages
From: jim rozen
Date: 13/07/03 04:40 GMT Daylight Time
Message-id:

In article ,

says...

Bore gauges are a must have if you do a lot of accurate i/d work. I have
three
sets. The main one for engine bores is a Mercer 2" - 6" which reads to a
tenth
of a thou. It does that fairly repeatably too.

I bought a couple of Federal dial bore gages at work
for some finicky bits. They are worth every penny.

Best is if you can set them with ring gages, I've
been making do with micrometers. Not right but
they still show variation at the 0.0001 level.

That's definitely the best way I agree, not that I have any and have to make do
with the mike for setting. It compensates for any error in how perfectly the
gauge lies across a true diameter of the bore it's measuring which is down to
the accuracy of the two contact feet on the measuring head. For engine work a
few tenths is neither here nor there really when most pistons have a tolerance
of -0/+0.001" on the bore size and plenty of production engines don't even get
within that 1 thou range.

For comparison work on bore taper and ovality, knowing the true size isn't so
important. For high precision engineering if you're trying to hit a tenth on
diameter I'm sure ring gauges play their part.


Dave Baker - Puma Race Engines (www.pumaracing.co.uk)
You find somebody to love in this world you'd better hang on tooth and nail -
the wolf is always at the door. (Don Henley - In A New York Minute)