At 02:50 PM 3/15/01 -0600, you wrote:
>How do you define 'Unobstructed'?
Chris,
I would define an obstruction as something like a steam tube was
flattened (but not collapsed) in making a tight bend, or where steam maybe
has to pass through a paper thin slit between the cylinder head and block
to get from the valve passages to the cylinder ends, something along those
lines. Of course it could also be an errant gob of solder, a wad of
packing or sealant, or some such.
>I would think a large line leading to a smallish cylinder would (snip)
>making it nearly impossible to let expansion be a factor in powering the
>engine.
I don't think that's a factor. Regardless of the size of the line
you are only going to have as much steam in the line as you admit through
the throttle. As soon as you pass the throttle the entire steam delivery
path, drypipe, valve chest, and the cylinder ends in admission cycle become
one continuous expansion chamber. Steam, being a fluid, will expand along
the path of least resistance, in this case, the retreating pistons (and
some though the glands). The amount of additional expansion allowed by the
difference in volume between a 1/8" line and a 3/16" line would IMHO be
imperceptible. What I'd think will affect the extent of expansion more
than anything else will be the amount of cooling of steam taking place
along that same path.
Cheers,
Harry
