The Airplane - Jay Spenser [97]
Mercury was the obvious choice for a filling, but it worked poorly. Then Heron found sodium, which is a liquid at engine operating temperatures, and a critical piece was added to the technological puzzle that is the reciprocating engine. Heron would make other contributions to engine design, metallurgy, and fuels development, but this was his most important.
To Frederick B. Rentschler, president of Wright Aeronautical, the Navy’s action was a golden opportunity. A talented propulsion engineer with business acumen and an entrepreneurial streak, Rentschler had spent World War I as an Army officer assigned to inspect U.S.-built Hispano-Suizas at the Wright-Martin plant. Subsequently joining the firm as an engineer, he had risen to lead it.
Fred Rentschler had promoted the Wright R-1, the company’s first radial project. Rejecting the conventional wisdom that liquid-cooled engines would always be dominant, he saw from the outset that air-cooled radials offered potentially greater simplicity, reliability, power-to-weight ratios, and total horsepower. Unfortunately, he couldn’t get his company’s conservative board of directors to agree with him. While he was glad now to gain Lawrance’s program as well, he thought big and wanted to pursue radials considerably more powerful than the 200-hp J-1.
Wright’s board continued to oppose him, so Rentschler quit late in 1924 and took much of the company’s engineering talent with him. The following summer they set up shop in Hartford, Connecticut, as the Pratt & Whitney Aircraft Company. Their first product, a nine-cylinder radial called the Wasp, was running before the end of the year.
As for Charles Lawrance, he became Wright Aeronautical’s new president. T. E. Smith, former head of the Air Corps Engineering Division’s Power Plant Section, arrived soon thereafter to serve as Wright’s chief engineer for a couple of years. Smith brought Sam Heron with him, and between them they restored the company’s technical expertise.
In short order, America had healthy competition between these two galloping giants of the aviation industry. They turned out successively better versions of this world-changing propulsion technology called the radial aero engine.
The J-1 and its immediate successors had significant teething troubles. Charles Lawrance and his engineering team made constant changes to this evolving product line. The J-4 of 1924—the first to bear the illustrious name Whirlwind—was quite good, although it too suffered from limited reliability.
Then Sam Heron extensively reworked the J-4’s cylinder design, creating the J-5 Whirlwind of 1926. Here at last was a radial engine that combined efficient combustion with adequate cooling thanks to its redesigned cylinder head, the use of sodium-filled exhaust valves, and other technical features.
The following year, Lindbergh showed the world just what the Wright J-5 Whirlwind could do (Heron personally visited the Spirit of St. Louis and fine-tuned its engine before the young flier’s departure). And soon the Wright J-5 Whirlwind was setting records in every corner of the globe.
Wright engineers were already at work on a more powerful radial series called the Cyclone. Pratt & Whitney would soon bring out its Hornet series as well as twin-row versions of its Wasp. These had a second bank of cylinders staggered slightly behind the first for adequate cooling.
A decade later, these two companies’ products would power most of the world’s airliners and many first-line U.S. military airplanes. By the latter 1930s, in fact, just one liquid-cooled engine would remain in U.S. production, that being the 600-hp Curtiss Conqueror. By then, Curtiss and Wright had joined forces in a 1929 merger to create the Curtiss-Wright Corporation.
Aerodynamic drag was