AIRCRAFT PROPULSION — TAYLOR 



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Figure 7. — "Liberty" engine, sectional transverse view. 



Thanksgiving Day, 1917, just 6 months after Vincent and Hall had 

 started their layout. I believe this record has never been equaled, 

 before or since, except perhaps by the first Pratt and Whitney 

 "Wasp," described later/ 



The design was based on the welded-cylinder construction pioneered 

 by "Mercedes." It had no radical features, but was an excellent 

 synthesis of the state of the art of its time. Its principal weaknesses 

 were cracking of the cylinder-head water jackets, burning of exhaust 

 valves, and breaking of accessory gears. These faults were gradually 

 reduced as time went on, and it was considered a reliable engine. 

 Early production engines had a 50 percent chance of passing the 

 government 50-hour endurance test. With later modifications, a bar 

 welded between the ports to reduce cylinder distortion and jacket 

 cracking, and heavier teeth for the gears, the only weakness remaining 

 was in the exhaust valves, which served well most of the time. 



■^ Although the "Wasp" did not go into real quantity production nearly as quickly as did 

 the "Liberty." 



