Friday, July 20, 2012

1936 Indian "Upside-Down" Four

Article By Motorcycle Museum

It was the answer to a question no one had asked: What was wrong with the Indian Four of the 1930s?

As it turned out, very little. But that didn’t stop Indian engineers from “improving” the design in 1936. And in the process, building one of the company's biggest flops.

But that’s getting ahead of a fairly convoluted story. So let’s go back 25 years, to an engineer named William Henderson.

In 1911, Henderson founded the motorcycle brand that bore his name, building a sophisticated four-cylinder motorcycle with the cylinders set in line with the frame.

By 1917, Henderson had sold that company to Ignaz Schwinn, the bicycle magnate who already owned the Excelsior brand. Within a couple of years, though, Henderson had started a second brand-Ace-selling an updated four-cylinder motorcycle.

Then Henderson died in a testing accident. And by 1927, Ace was forced to liquidate its assets.

This is where Indian comes in. The company was looking for a flagship motorcycle to give it an edge against its rival, Harley-Davidson, and the Ace Four seemed to fit the bill.

At first, Indian marketed the same motorcycle Ace had been making. But 1½ years later, the company put the Ace engine into a frame modeled after its successful 101 Scout, and the Indian Four was born.

Then the Depression hit. And suddenly, sophisticated fours were too pricey for the market. One solution would have been to drop the Four and concentrate on other machines. But Indian engineers thought they had a way to make the Four better.

The result was this bike, known as the “upside-down” Four because of its engine configuration. Previous models had the inlet valves over the exhaust valves-a design that was typical of the era. But the 1936 Indian had its exhaust valves over the intakes, resulting in an engine with the carburetors down low and the exhaust pipe up top.

The idea made sense on paper. Excess heat could vent directly to the air, while the carbs could vaporize fuel better. At least, that was the theory. But in practice?

“You can really feel the heat off the engine,” says owner Dick Winger of this 1936 Indian Four, now on display in the Motorcycle Hall of Fame Museum at AMA headquarters in Pickerington, Ohio. “If you weren’t careful back then, you’d boil the grease right out of the top end.”

A dual-carb setup, offered in 1937, didn’t help, and by 1938, the “upside-down” Four was discontinued, replaced by a new “rightside-up” design.

Indian continued to make Fours through 1943. But rightside-up or upside-down, the golden age of American fours had passed. To this day, V-twins rule.


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