The Engine that Powered the Reproduction Wright Flyer

by Dr. Richard Stimson

in Kitty Hawk 2003 Celebration Events

As the person responsible for the reproduction engine that powered the reproduction 1903 flyer that flew at the Wright Brothers National Memorial during the Centennial Celebration, Greg Cone of the Wright Experience pampered the engine.

Greg didn’t build the engine. Jim and Steve Hay, the owners and operators of the Hay Manufacturing Co. in Minnesota did that. Their company’s primary business is making trumpet parts, steel stampings and tool work.

They also build antique engines. They built their first 1903 Wright engine in 1976. This engine was first run at the EAA convention in 1977 and has been run during every EAA Convention since then.

The Wright Experience had Hays build three engines for the reproduction 1903 Flyers.

Greg said that when the engines arrived at The Wright Experience he disassembled them for inspection and carefully put them back together. He said that if he was the one responsible for them, he had to make sure they met with his satisfaction.

At the Wright Memorial I watched Greg and the others start the engine in the Flyer several times. Greg would bend over the engine carefully adjusting it while two assistants spun the propellers to start the engine. It usually took a number of tries before the engine would start. It would cough a few times before kicking-in.

Sometimes it wouldn’t start at all. Such was the case after the successful flight of Nov. 20. They tried a number of times to get it started but they had to gave up for the day.

On another occasion the engine started but ran roughly because all four cylinders were not firing properly. The usual problem was that the points and/or combustion chambers became contaminated from the 50-octane gas, which was the same octane gas that the Wrights used. When this occurred the points and the inside of the combustion chambers had to be thoroughly cleaned.

Perhaps the best performance given by the engine was on the flight of Dec. 3rd. As the Flyer began to lift off the launching rail, it was hit by a crosswind and began to roll to the right. The right wing plowed sand while Kevin Kochersberger struggled to make a correction. This placed an extra heavy load on the engine. The engine groaned but kept going and Kevin was able to fly 115 feet.

I asked Greg if he primed the engine before starting it. He said that was a judgment call. Sometimes he did, but he had to be careful because there was a danger of fire if it was primed too much.

The engine was relatively simple. Fuel flows by gravity from a can into a reservoir in the top of the crankcase, where it vaporizes and mixes with the air flowing into the cylinders. Instead of spark plugs, it has igniters that close like switches when a cam turns, then spark as they separate.

Some people think that the Wrights heated the cold engine before starting it. I can find no evidence that this was the case. There is no carburetor. The fuel is fed into a shallow chamber in the manifold situated next to the cylinders where it heats up, quickly vaporizing the air-gas mixture.

The cooling system for the engine consists of gravity feed from the radiator that is marginally effective. The Wrights sometimes ran the engine “red-hot.”

A dry battery that is not a part of the plane is used to start the engine. Once started, a magneto on the plane takes over and provides continuous electricity at 10-volts.

The original engine was designed by the Wrights to produce 8-hp, but did better than expected and was able to produce 12-hp.

Greg said they were able to produce 18-hp on the dynamometer with the reproduction engine, and on a test flight, they produced 20-hp @ 1100-rpm. (The Wrights liked to run the engine at 1150-rpm on their 1903 machine.) Greg said the engine got stronger with each run. Their longest run was 9 minutes.

Here are some pictures:

The first picture is of Greg with the engine in the background.

The second picture is of Greg starting the engine.

The third picture is of the remains of the original 1903 engine block showing the 3 cylinders that remain. The engine broke when a sudden guest of wind at Kitty Hawk overturned the stationary airplane. The missing cylinder, however, was not caused at Kitty Hawk, but was deliberately broken off sometime later and used for casting new parts.

The buckeye Iron and Brass Works in Dayton provided the 1903 aluminum casting made from Alcoa aluminum. An aluminum casting was innovative for that time because aluminum was not yet used for gas engines.

The fourth picture is an outline drawing of the 1903 engine that appears in Charles E. Taylor by H.R. DuFour. The Wrights did not make any engineering drawings of the engine. They provided sketches to Charlie Taylor, their mechanic, who then made the engine from them. He had an operating engine on Feb 12, 1903 in only 6 weeks.

Unfortunately, the next day the engine body and frame were broken when the bearings seized due to inadequate lubrication. A new aluminum casting was received at the Wrights’ shop in May and the rebuilt engine was tested in May.

This was not the first gas engine designed and built by the Wrights. They had earlier built a one- cylinder engine to power the machine tools in their bicycle shop. It used the natural gas used in the gaslights.

The fifth picture is a picture of a restored 1903 engine.

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