Flathead engines

  • Flathead engines - Manufactured between 1929 and 1974. Flatheads did not have overhead valves. Instead, the valves ran alongside the engine and opened upwards into a chamber beside the combustion chamber. The advantage of a flathead was simplicity -- no pushrods or rocker arms, and the head was a simple casting with a hole in it for the spark plug. A typical flathead engine had a displacement of 45 cubic inches (742 cc) and produced about 22 horsepower.

a flathead engine
Basic design of a flathead engine.

The 2003 Screamin' Eagle Softail® Deuce

a 2003 Harley Screamin' Eagle Softail Deuce
Photo courtesy Harley-Davidson Motor Company
The 2003 Screamin' Eagle Softail® Deuce, shown here in custom paint colors - Centennial Gold and Vivid Black.
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First Harley-Davidson

The very first motorcycle was built in 1885, but the first Harley-Davidson Motorcycle, pictured here, was built in 1903. See a modern motorcycle on the next page.
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