| The
Little Engine That Would
In December of 1902, the Wright
brothers sent out letters of inquiry to 10 different manufacturers
of gasoline engines, asking for an engine that could develop 8-9
horsepower, weigh no more than 180 pounds, and be free from
vibration. All 10 replied they did not make such an engine.
Disappointed, Wilbur sought out Charlie Taylor, a machinist they
had hired to run their bicycle shop during previous sojourns to
Kitty Hawk.
"We'll just have to build our
own," Wilbur told Taylor. "I suppose I don't have to ask
why you want it," his friend replied. "That's
right," Wilbur agreed. "We are going to put it on our
machine. Next year at Kitty Hawk, we are going to fly."
Taylor had never built an engine,
but he was a first-class machinist. Wilbur and Orville had
designed the motor that drove the line shaft in their bicycle
shop. What they decided on was a four-cylinder engine, bore and
stroke at four inches, that developed 12 horsepower and weighed no
more than 180 pounds. "While the boys were handy with tools,
they had never done much machine work," Taylor recalled,
"and anyway, they were busy on the air frame. It was up to me…We
didn't make any drawings. One of us would sketch out the part we
were talking about on a piece of scratch paper and I'd spike the
sketch over my bench."
Taylor's procedure was simple.
After tracing the outline on a slab of machine steel, he would
then drill through with a drill press and knock out surplus metal
with a hammer and chisel. Then it went on a lathe, where he turned
it down to correct size and smoothness. To save weight, the body
of the engine was cast aluminum, with cast iron pistons and rings.
The fuel system was a one-gallon tank suspended from a wing strut,
with the gasoline fed by gravity to the engine. There were no
spark plugs or batteries on the plane. The engine was started by
priming each cylinder with a few drops of raw gas, the spark
produced by the closing of two contact points inside the
combustion chamber. Dry batteries started the engine, but after
that a magneto took over.
On February 12, 1903, the little
engine ran for the first time - just six weeks after Taylor had
begun. Unfortunately, the cooling system was poor and the valve
box grew red hot after a few minutes operation. The second day of
testing, dripping gasoline froze the bearings, shattering the
crankcase. A new casting could not be delivered for another two
months. During that time, the valves were fitted with heavier
springs so fuel consumption was cut in half and output increased
to 16 horsepower - far more than what the Wrights had originally
felt necessary. Based on that figure, they felt comfortable adding
a bit more weight to the craft, with improvements that made it
more sturdy.
The engine was successfully
block-tested a final time before crating for its shipment to Kitty
Hawk in the fall. Said Taylor; "We rigged up a resistance fan
with blades an inch and a half wide and five feet two inches long.
The boys figured out the horsepower by counting the revolutions
per minute. Those two sure knew their physics. I guess that's why
they always knew what they were doing and hardly ever guessed at
anything."
This "Kitty Hawk
Moment" is brought to you by EAA, whose Countdown to Kitty
Hawk program, presented by Ford Motor Company, includes an exact
flying reproduction of the Wright Flyer. It is the centerpiece of
EAA's national tour during 2003, which will conclude with a
five-day celebration at Kitty Hawk, North Carolina, where the
Wright flyer will fly again at exactly 10:35 a.m. on Dec. 17,
2003, commemorating 100 years of powered flight.
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