SMALL and PRETTY

were sold in the U. S. as well. Maybe some of the engine collectors
who get The Iron-Men Album could give us some information on this.
We would be very interested to hear from anyone who has an engine
similar to this one.

The local history on this engine is that it was purchased new,
shortly after 1900 by a Mr. Alex McCloud of Bristol, Quebec. Mr.
McCloud used the engine on his farm for grain threshing up until
about 1920. The engine was then sold to a Mr. Woolsey, who used the
engine for threshing grain until the late 1940’s. A Mr. Neil
Drummond of Bristol, Quebec then purchased the little steam engine
for work on his tobacco farm. It was used to steam the seeding beds
in preparation for the tobacco plants, among other jobs for a
period of 4 or 5 years.

The engine then sat idle in an old shed for almost 20 years. In
1973 the engine was acquired by Mr. Eric J. Campbell of Shawville,
Quebec. By that time the engine had deteriorated to a pitiful
state. Mr. Campbell brought the engine up to his farm workshop
where he started the tremendous task of restoring it. After many
hard hours of work repairing badly worn axles, grates and ash pan,
which had long since fallen out, the engine looked like it might
run again. Piping and valves had to be replaced and a new rear
platform built. Despite all this, the boiler and engine parts were
in good condition.

After almost 3 years of hard work in spare time, the engine was
ready for the final coat of paint. All the hard work was not in
vain, because the little engine runs as good as it did 75 years
ago. The proof of this was the 100 acres of grain that was threshed
with the engine this Fall. ‘She’s not big, but she sure is
pretty and we are all proud of her.’

A number of enthusiastic steam and gas engine collectors here in
Pontiac County, Quebec have formed a club. We call it the Pontiac
Steam and Gas Association. We believe it is the only steam and gas
engine club in the Province of Quebec. If there are others, we
would be glad to hear from them. We make our headquarters near
Shawville, a small town about 45 miles north of Ottawa.

We held our first steam and gas show this year at the farm of
Eric J. Campbell, who is the president of our association. There
was a very good turnout at this show and we are making plans for a
bigger show next year.

Early in the steam era engine builders learned a way to avoid
wearing shoulders on valve seats and cylinder walls.

In the case of the slide valve seat, the raised part of back of
the steam-chest against which the valve slides, is made only about
the width of one steam port wider than the valve. This causes the
edges of the valve to slide off the edges of the seat for about the
width of the port at the end of each stroke, so there is no place
for a shoulder to form. All locomotives and most traction engines
have valve gears that can be ‘hooked up.’ When running
hooked up, the valve will have a shorter travel, but any time it
has stroke enough for the engine to run, the edges will be clearing
the valve seat. If the valve seat is wide enough so that the valve
does not slide clear a shoulder will form. This will cause trouble
even if the engine is always run in full gear.

To prevent wearing shoulders at the end of the piston stroke in
the cylinder, it is made with what is called the ‘counter
bore’ at each end. This means that for a distance of about
three-fourths to one inch depending on the size of the engine, the
cylinder is bored about one eighth inch larger than the main bore.
When the clearance is properly adjusted about one third the width
of the piston ring will pass into the counter-bore so no shoulder
can be formed.

SHOULDERS ON VALVE SEATS

Carl B. Erwin,106 South Elm Street, Newkirk, Oklahoma 74647

Back 60 or 70 years ago it would have been wasting paper and
time to have been writing about these things, as all machinists who
worked on steam engines and most operators knew about them, but now
at steam engine shows we hear the younger operators and model
builders talk – about wearing shoulders on valve seats. Also, I
have seen cylinder castings that had been sold to model builders
that were made with the valve seat extending over the whole back of
the steam-chest. This kind of seat will soon wear so as to leave a
shoulder at the end of valve travel. Any mechanic knows that this
is bad for the operation of the engine. Any change in the stroke
due to wear, changes in adjustment of lead or even the changes in
the length of the eccentric rod from difference in temperature will
cause the valve to ride on the shoulder and perhaps start a
leak.

This sketch shows the ‘D’ slide valve. The crank is at
the dead center with the piston at the head end. The left end of
the valve is opening the port one thirty secondth of an inch, and
the right end is passing off the edge of the seat. About one eighth
inch of the piston ring at the left has passed into the
counter-bore. The clearance and counter-bore are proportioned so
that the entire width of the ring cannot enter the
counter-bore.

The sliding surface of the cross-head guides is made the same
way. The cross-head shoes pass about one fourth inch off the end of
the bearing surface of the guides on any well designed engine.

Sketch showing ‘Double Ported Valve.’ The port at the
left is beginning to open. At the right the inside passage is
sliding off the seat and allowing steam to pass over the exhaust
chamber to admit additional steam to port at the left. This gives
higher initial pressure and improves performance of the engine. The
double-ported valve was widely used on locomotives that were
equipped with the Stephenson Link reversing gear. One fault of this
gear was that it opened the ports slowly.

Also, I would like to mention the Steam Engine show that was
held at Pawnee, Oklahoma last July. The folks down there have a
fine lot of engines, threshers, early model tractors and about
everything else that was ever used on the farm. One especially
interesting engine is a Corliss engine that looked to be about 600
H.P. direct connected to an alternator. This engine and generator
were built by Allis-Chalmers probably 50 or 60 years ago. They have
it erected in fine shape and running nicely. You people from back
east should come down and see us. (I mean you all come.)