The Airplane - Jay Spenser [96]
Wright-Hissos were in strong demand, so there was little incentive for the company to undertake a costly new line of development. Moreover, Wright Aeronautical was then developing an air-cooled radial of its own, the R-1, for Army evaluation at McCook Field. So troubled was that experimental engine that Wright was not eager to take on more.
At this juncture, the Navy did something of seismic consequence that would change aviation for the better. To be certain of sufficient manufacturing muscle behind the Lawrance J-1, it arranged for Wright Aeronautical to acquire Lawrance’s firm and build his engine. And with Wright’s board of directors dead set against the plan, it required a bit of blackmail.
Naval leaders in Washington, D.C., informed Wright Aeronautical in 1922 that the service would buy no more Wright engines or spares from the firm if it refused to acquire Lawrance Aero Engines. The Navy being a major customer, Wright had no choice but to comply, and in 1923 the J-1 became a Wright product. Charles Lawrance, Wright’s new vice president, relocated to its corporate facilities at nearby Paterson, New Jersey.
The handwriting was on the wall. With the Army now also pursuing radial technology, notice had been served on the nation’s aero engine industry (then led by Wright, Curtiss, and automotive giant Packard) that the U.S. government would no longer foster two parallel lines of technological development. In the future, air-cooled radials would be favored for public development and procurement funds.
Sam D. Heron spent World War I working at the Royal Aircraft Factory, Britain’s flight research center at Farnborough, southwest of London. While there, this Englishman in his mid-twenties participated in the first comprehensive scientific studies ever performed of engine-cylinder air cooling.
Airplanes flew rapidly through the air, so it was logical to want to use the slipstream to cool their engines. Unfortunately, metallurgical knowledge and metal fabrication techniques were not yet sufficiently advanced to allow airplanes—other than those with spinning engines that force-cooled their cylinders—to dispense with the weight and complexity of liquid-cooling systems with radiators.
The son of an actor, Heron had attended night schools but lacked resources for a degree. Instead it was an apprenticeship as a mechanic and foundry worker that won him participation in Britain’s wartime developments. While there, Heron helped design the world’s first successful air-cooled aluminum cylinders.
Heron was a difficult personality but his genius for engine design was clear. After brief stints at engine makers Rolls-Royce, Napier, and Siddeley, he allowed the United States to hire him away in 1923 as a civilian researcher in the Power Plant Section of the Air Corps’ Engineering Division. He found his niche at McCook Field. It was there that he invented the sodium-filled valve, a key technology that made the high-power aero engine possible. Cylinder exhaust ports and valves are the hottest parts of any internal-combustion engine, so it is here that the cooling challenges are greatest. As for the valves themselves, they are disc-shaped metal plugs mounted on stems that rise or fall at high speed to open or block off access to a cylinder as the engine operates. Opened during the exhaust stroke, these valves are exposed to the hot, high-pressure flow of corrosive exhaust gases.
Heron’s brilliant idea was to hollow out