By 1960, of the 25 tractors tested at the Nebraska Tractor Test Laboratory, 14 had diesel engines. Fifteen years later, in 1975, all 30 tractors that were tested in Nebraska were powered by diesels. Today, engine modifications continue to improve fuel efficiency and boost horsepower. Consider, for example, that the Massey-Harris Challenger with its 247.7-cubic-inch engine cranked out just 28.58 horsepower on the belt when it was introduced in 1936. Seventy-seven years later, Massey Ferguson released the Model 5613, which is considered to be a utility tractor, rated at 125 engine horsepower and 100 horsepower on the PTO. In comparison to the Challenger’s 4.1-liter engine, the 5613 has a four-cylinder engine that is only slightly bigger at 4.4 liters.

The difference is today’s model uses a turbocharged, intercooled diesel engine rated at 2,200 rpm that uses four valves per cylinder. In addition, it utilizes a high-pressure common rail direct-injection fuel system that feeds an injector at each cylinder. If that’s not enough to think about, consider that today’s automobiles are often powered by engines with a displacement of three liters or less, when six or eight cylinders were the norm just 30 to 40 years ago.

Engine designers continue to modify engine components to crank more power out of fewer cubic inches, all while generally increasing the engine lifespan and decreasing the emissions. So let’s take a look back at tractor engine evolution to see where we’ve been, and how we got to where we are today.

Rumley OilPull 30-60

Advance-Rumely 30-60 OilPull was introduced in 1910 as the production version of the “Kerosene Annie,” the first kerosene-powered tractor built by the M. Rumely Company as an experimental model. Like the original, it was an onerously heavy machine, weighing approximately 26,000 pounds—almost as much as the steam engines it was meant to replace. Even with 75 horsepower, it took nearly half of its power just to move the tractor, let alone any load. The first models were essentially variations of the company’s steam engines converted to internal combustion; hence, they were still suited only for the largest farms and for threshing work.

In addition, the two-cylinder engine had such a large displacement (1,885 cubic inches) that it was too large to crank and, instead, had to be started with compressed air. Still, it was enough of a positive change to launch Rumely into an era of rapid growth.

The OilPull’s biggest selling point, of course, was the fact that it ran on kerosene, which at the time sold for around seven cents per gallon. Compared to steam engines, it meant the operator no longer had to handle coal or wood or wait for steam to build up in the boiler. Better yet, there was no boiler to explode with devastating results.

On the other hand, it could be operated much more cheaply than a gasoline-powered tractor, since gasoline was more than twice the price of kerosene at 16 cents per gallon. According to company promotional material, that could amount to a difference of $4.50 per day—a large amount in 1910. Of course, the Advance-Rumley’s ability to run well on kerosene, which had a much narrower temperature band, was attributed to two engine features. First it was oil-cooled instead of water-cooled. Since oil has a much higher boiling point than water, this allowed the engine to run hotter, which permitted better combustion of kerosene. Key to temperature control was the large cooling tower at the front of all Rumely OilPull models. The exhaust was routed through the tower to create airflow, or air suction through the cooling unit without the use of a fan. The second thing that helped was water injection, which was controlled by the governor, to regulate combustion.

However, the 30-60 was rather slow in every sense of the word. There was only one forward speed at 1.9 miles per hour and one reverse speed. The engine’s cycle was equally slow with a rated speed of only 375 rpm. That began to change, though, with Generation Two of the Advance-Rumely tractors. In addition to lighter weight, they featured a slightly higher engine speed and two forward speeds.

Although the Advance-Rumely OilPull 30-60 was in production for nearly 13 years, easy starting and improved performance eventually allowed gasoline, despite its higher price, to become the preferred fuel among farmers, ultimately bringing an end to all kerosene tractors.

John Deere Waterloo Boy N

It’s difficult for most people to think of a Waterloo Boy as anything other than John Deere’s first successful farm tractor. But the fact is, the Waterloo Gasoline Engine Company, which was organized in 1895, as an engine manufacturer, actually developed and initially marketed the tractor. The Waterloo Boy had evolved from a self-propelled tractor designed in 1892 by John Froelich. Although the Froelich tractor never became a commercial success, it did form the base for the company’s stationary, horizontal, two-cylinder engines—even though Froelich himself had since left the company.

In 1913, with the hiring of two new engineers, the Waterloo Gasoline Engine Company took a renewed look at powered tractors in response to changes in the marketplace and developed the Waterloo Boy One-Man Tractor. The company started with the Models L and LA, both of which featured a single-speed transmission. Both had an engine with a cylinder arrangement that was horizontally opposed. The L was a three-wheel model, while the LA was the same tractor with a wide front. Unfortunately, only a few models of each were ever sold.

In the meantime, Waterloo Boy developed a new side-by-side, two-cylinder, four-cycle engine. This engine was then installed on an LA chassis to become the Model R. Like the L and LA, it still had only one forward gear, and steering was accomplished with a chain windlass steering system.

In 1917 the Model N was added. However, the latter was equipped with a two-speed gearbox instead of the single speed and featured a worm and sector–type steering. The largest of the models, it offered 12 horsepower on the drawbar and 25 on the belt with the engine running at only 750 rpm on kerosene.

As most everyone knows however, the Waterloo Boy tractors soon attracted the attention of John Deere, which had serious ambitions to move into the rapidly growing tractor market. Not only had John Deere been unsuccessful at developing its own tractor model, but company executives reasoned that purchasing an established product would be a shortcut in developing both a unit to sell and an established market. Buying the Waterloo Gasoline Engine Company would not only solve those issues, but provide Deere & Company with its own engine factory.

The Deere & Company acquisition was completed in 1918 at a cost of $2.35 million for the entire Waterloo Gasoline Engine Company. The Model N remained in production with only minor changes until 1923—carrying the Waterloo Boy name the entire time. It wasn’t until late 1923 when Deere introduced the Model D, calling it a 1924 model at the time, that the reign of the Waterloo Boy came to an end.

International Harvester 8-16 Junior

Like a number of tractor manufacturers in the 1900s, International Harvester was formed as a merger of two major farm equipment companies that were forced to become partners in order for both to survive. It happened to Holt and Best when the former enemies reluctantly joined forces to form Caterpillar in 1925.

The merger of the McCormick Harvester Company and the Deering Company several years earlier, in 1902, was no more welcomed by company executives and dealers. In effect, the two merged companies continued to operate much as they had before, to the point of developing two different tractor lines—Titan and Mogul. Most of those early tractors, however, were designed for plowing and belt work, leaving jobs like cultivation, planting, and mowing hay to a team of horses.

In an effort to mechanize those tasks, too, companies began looking at small tractors by the 1910s. Mogul came out with their answers in the form of an 8-16 and 12-25, while Titan introduced the 10-20 and 12-25. It wasn’t until 1917 that the Mogul and Titan tractor engineers were pulled together into one department with a single goal. One factor that prompted the merger was the new Fordson tractor. Introduced the same year as International Harvester’s engineering consolidation, it was small and affordable and was proving to be serious competition for all tractor manufacturers, including International Harvester.

One of the first tractors to come out of that joint effort was the International 8-16 Junior, not to be confused with the 8-16 Mogul introduced in 1914. Often referred to as the “kerosene” tractor, the 8-16 Junior was a small tractor that was designed after the existing International trucks. Not only did it have the same style of sloping hood, but it used the same engine as the Model G International truck. The 8/16 also had a three-speed transmission—an unusual feature at a time when one and, at most, two speeds were the norm—and a fan-cooled radiator, which actually was positioned behind the engine.

Reprinted with permission from Tractor Superstars by Tharran E. Gaines and published by Quarto Publishing Group, 2015. Buy this book from our store: Tractor Superstars.