This thread is so ridiculous.
Michael F. Adamson wrote:
> The illustration you used is not valid because you are dealing with a
> narrow ring of material that does expand when heated; the inside and
> outside diameter does get larger due to the shape of the part.
Irrelevant. Uniform things grow uniformly and keep
all proportions the same. The shape doesn't matter or
change, if the heating is uniform.
> The very important difference is that you are not dealing with a large mass
>of the
> material.
Also irrelevant. Laws of physics don't change for
big and small things.
> If your analogy held true, then an engine block with pistons of the same
> material, with the same coefficient of expansion, should never sieze when
> overheated or even get difficult to turn over. As the pistons expand so
> would the bore, no problem: wrong!
So many things are confused here. If we are going to attempt
a scientific discussion you have to keep it scientific.
A seizing engine is a mish mash of so many problems, don't forget what
overheating does for oil viscosity which is a huge factor. That and
parts melting and becoming misshapen or causing parts to fuse
together.
> Next someone is going to cite the heating of a siezed bolt to release it
> from a casting. It works except it shouldn't.
It works because changing the sizes of things causes tiny
bits of motion on mating surfaces. This motion breaks rust
bonds. It doesn't actually matter what is growing or
shrinking for many situations, as long as the two parts
do it slightly differently.
--
Trevor Boicey
Ottawa, Canada
tboicey@brit.ca
http://www.brit.ca/~tboicey/
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