Advertised by the Downing Engine Works of Des Plains, Illinois
in 1906 for $125.00, the 3 horsepower "Bill" engine
is somewhat of an enigma. A patent was issued to William A. Downing
for the design but it is not known how many were actually produced,
if any. The very simple and attractive engine was probably intended
for light duty work such as pumping water, powering a grinding
wheel or a small dynamo, etc. A listing for the "Bill"
can be found on page 141 of American Gasoline Engines Since 1872
by C.H. Wendel.
This is an approximate 1/3 scale model of the 1906 "Bill"
engine. It runs on propane gas. On liquid fuel, due to the remoteness
from the engine, the mixer soon gets cold from liquid fuel vaporization
and after that the fuel doesn't vaporize very well which results
in ragged operation. A propane demand valve was made for it and
running on propane solves that problem. I have to presume that
the prototype engine encountered the same problems (it may have
ran on illuminating gas), but there was no propane to the rescue
back in those days!
Engine operation on propane is a big plus. Valves and spark plug
stay very clean and there is no smelly exhaust! I have been changing
the crankcase oil every 10 running hours since break-in but it
still looks new, so I am going to extend it to 20 hours. This
wouldn't be the case using a liquid fuel.
"Bill" is machined and fabricated primarily of brass
bar stock. The only castings used are the pipe elbows. The crankshaft
runs on ball bearings, the cylinder has a cast iron liner and
the piston is aluminum alloy.
The plans set consists of 18 pages of drawings plus a page of
construction notes. Included in the plans are a propane demand
valve, radiator/water pump/fan and details on mounting a Hall
sensor and magnet so that electronic ignition can be used without