"Steve W." wrote in message
...
Phil Kangas wrote:
wrote in message
...
On Feb 11, 8:35 pm, "Phil Kangas"
wrote:



Yah, but, the flywheel is cast iron and the
ring
is steel. Cast won't
move as much as steel. We need some actual
measurements!!

Per The Engineering Toolbox

Grey cast iron 6.0 (10-6 in/in oF)

Steel 7.3 (10-6 in/in oF)

Dan

We need to actually 'measure a flywheel' !
phil





WHY? I have installed probably 50 ring gears and
other assorted items
this way over the years. Used this same set of
temps for years.

This is also the factory method for the
particular engine.

It falls into the category of "Don't fix what
ain't broke"

--
Steve W.

Awl riiight..... Let's crank some numbers he
Both the ring gear and flywheel are at 70 F., 12
inch wheel.
Cool the flywheel to -20 F., 90 deg change.
0.000006 x 12 x 90 = 0.00648 reduction in dia.
Heat the ring gear to 400 F., 330 deg change.
0.0000073 x (12 x pi) x 330 = 0.09082 expansion.
(12 x pi) + 0.09082 = 37.78993 heated "length".
37.78993 ÷ pi = 12.0289
So we get the ring to expand 0.0289" in diameter
and the
wheel shrinks 0.00648 inches. So I ask you, do you
still
think you need the 0.00648? I don't think so, it's
a waste
of time to freeze the wheel. That's my answer and
I'm
sticking to it. I don't care one whit how many
you've done.
phil k.