Standing side by side in their bicycle shop, the Wrights watched as Charlie Taylor, their only employee, made a few final adjustments to the four-cylinder gasoline engine he’d just finished custom-building as the power source for the odd craft the brothers were fabricating. It was a tense moment. Two months earlier, Orville Wright had contacted no fewer than 10 manufacturers in a fruitless search for an engine with a power-to-weight ratio sufficient to spin two large counterrotating wooden propellers and coax their fragile aircraft down a rail track and into the sky. But none of the engine manufacturers that Orville heard back from produced an engine that met the Wrights’ specifications — what was worse, none was willing to build one.
Out of options, Orville and Wilbur put the project in the hands of Taylor, who was originally hired to fix bicycles but soon took over day-to-day operations at the shop while the brothers devoted nearly all of their time to perfecting their aircraft designs. The Wrights instructed Taylor to build an engine that weighed no more than 180 pounds and produced at least 8 horsepower. Taylor, whose only experience with gasoline engines consisted of a botched attempt to fix one once, delivered an engine capable of producing more than 12 horsepower — and he did it in only six weeks.
It should be pointed out that Charlie Taylor’s engine was crude, even by the standards of the day — he was hired as a bicycle repairman, after all. But the engine ran, and in many ways it was also an engineering work of art. To save weight, Taylor had a local foundry produce the crankcase from aluminum. Of necessity, the engine was water-cooled, and the fuel was gravity-fed from a can mounted on an inboard wing strut. The engine had no fuel pump, carburetor, spark plugs or even throttle. Ignition was achieved by the opening and closing of contact breaker points. Four dry-cell batteries (which remained on the ground because they were so heavy) were used for starting, after which a low-tension magneto driven by a 20-pound flyweight supplied the electrical spark to keep the engine running.
When Taylor started the engine for the first time in February 1903, it popped and sputtered to life and ran surprisingly well — but it soon glowed red-hot around the exhaust valves. Taylor began tinkering with various fuel-air mixtures, but he overdid it — the engine seized and the crankcase shattered in its mounts. Taylor had to completely rebuild the engine, but that first test was deemed a success. The Wrights knew the engine could work. By May of that year Taylor had discovered the proper fuel-to-air ratio that allowed his creation to run smoothly. And on the morning of Dec. 17, 1903, Charlie Taylor’s wonderful little engine churned at its mightiest, powering the Wright Flyer and its inventors into the history books.
It’s amazing that well over 100 years later, light airplanes are still being powered by reciprocating piston engines with aluminum crankcases, gravity-fed fuel systems, in-line cylinders, magnetos and even water cooling in some designs. Still, a modern piston engine produced today bears no more resemblance to early aircraft engines than a brand-new Cirrus SR22 does to the Wrights’ first pusher biplanes. And even though little is different in the certification basis of, say, a 1970s piston aircraft engine and one built today, as we’ve hinted at, plenty has changed — and all of it for the better.