1936 Harley-Davidson EL

Birth of the Knucklehead

1936 Harley-Davidson EL

The year was 1931—the height of the Depression. The last thing any motorcycle company could afford was the kind of spending it would take to produce an all-new model.

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But that’s exactly what Harley-Davidson officials approved when they green-lighted the new-from-the-ground-up Model E. And when the finished machine was released five years later, that decision proved to be one of the company’s smartest ever.

Much was riding on the new Model E. At the time, the Motor Company’s lineup consisted of a smaller, single-cylinder bike, plus a couple of aging V-twins displacing 45 and 74 cubic inches (about 750cc and 1,200cc, respectively). The target was a bike with the light weight of the 45 coupled with power rivaling the 74.

The engineering required to achieve that goal was impressive. The old side-valve design was replaced with the first overhead valves to appear on a production Harley V-twin, operated via pushrods from a single, multi-lobed camshaft. Those valves were set at right angles to each other, an idea taken from aircraft engines. A recirculating oil system with a dry sump was used, and the new motor was coupled to a four-speed gearbox via a chain primary drive.

The result was a simple, reliable powerplant that produced a claimed 37 horsepower in the base Model E, and 40 ponies in the higher-compression Model EL.

But when it was released in 1936, it was the appearance of the new engine that attracted attention. The prominent rocker boxes, looking like knuckles on a fist, quickly earned the engine the nickname of the “Knucklehead.”

The Model E’s cachet only went up when racer Joe Petrali took a tuned EL to a record 136.183 mph at Daytona, and Fred Ham rode an E 1,825 miles in 24 hours.

At a time when Excelsior-Henderson was getting out of the motorcycle business and Indian was struggling to survive, the modern Knucklehead installed H-D as America’s premier motorcycle company. And it formed the basis for the Panheads, Shovelheads and even the Evolution motors that followed, taking the company all the way into the 1990s.

All that has made first-year Es—and especially ELs like this unrestored example owned by Dave Minerva—some of the most sought-after Harley-Davidsons of all time. Clearly, the gamble paid off.

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Engine
45-degree
overhead-valve
V-twin

Displacement
61 cubic inches
(1,000cc)

Transmission
Four-speed

Tires
4.50 x 18-inch

Weight
565 pounds

Owner
Dave Minerva

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