1929-1952 Harley-Davidson WL WLA 45″ Engine Overhaul Service Manual
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The 1929-1952 Harley-Davidson WL/WLA 45-cubic-inch engine is a reliable, side-valve (flathead) V-twin engine that powered many civilian WL and military WLA motorcycles and post-war Servi-Cars. This versatile and rugged 750cc motor, known for its simplicity and ease of repair, produced around 24 horsepower and was known for its longevity, remaining in production until 1973.
Key Features and Characteristics
- Type: Side-valve or “flathead” V-twin engine.
- Displacement: 45 cubic inches (750cc).
- Power Output: Approximately 24 horsepower.
- Compression: Very low compression ratio (e.g., 5:1 for the WLA) designed for reliability and to run on lower octane gasoline.
- Valves: The valves are located in the cylinder block, next to the cylinder, with the intake and exhaust ports positioned similarly.
- Simplicity: Designed for ruggedness and ease of maintenance, allowing it to be disassembled with minimal tools in field conditions.
- Longevity: One of Harley-Davidson’s longest-running and most versatile motors, used from 1937 through the 1973 Servi-Car models.
Applications
- Civilian WL Models: The base civilian version, known for providing reliable and economical rides.
- Military WLA Models: The military-spec variant used by the U.S. Army during World War II.
- Servi-Cars: The engine powered the three-wheeled Servi-Car, which continued in production for decades.
- WR Racers: It was also used in factory WR racing models.
Historical Significance
- Wartime Contribution: The WLA was a crucial and widely produced motorcycle during World War II.
- Post-War Use: After the war, many ex-military WLAs were stripped down into “bobber” style motorcycles.
- Successor Model: In 1952, the WL engine was superseded by the new unit-construction Model K, which was the ancestor to the modern Sportster.
