Cummins diesel engines are so ubiquitous and commonplace today, they're practically synonymous with the term "heavy duty diesel." The company's visibility and reputation only grew following the debut of the company's engines in the Dodge Ram truck line in 1989, introducing the company's products to the broader consumer market.

In its early days, however, the company was far from the global corporate titan it is currently. The combination of a trouble-prone licensed design from a Dutch diesel engine company and the Great Depression almost buried the company before it truly got its footing. The indomitable spirit of its founder, Clessie Cummins, kept the company alive, ultimately leading to the thriving business that is the Cummins we know today.

A Unique Relationship

Before the founding of his eponymous diesel engine company, Clessie Cummins worked as a chauffeur and mechanic for William Irwin, a banker in Columbus, Indiana. Although he had no formal education beyond the eighth grade, Cummins had a keen knack for the mechanical, which was noticed by Irwin. Legend has it that when Cummins was only 11 years old, he built his own steam engine from molten cast iron he poured into wooden blocks that served as molds. His homebuilt steam engine was used to pump water for his father's farm.

Cummins reportedly saw his first diesel engine around 1918, an imported engine from the Dutch manufacturer Hvid. Through correspondence and negotiations with local representatives, Cummins received a license to build Hvid engines for the U.S. market. After securing the licensing deal with Hvid, Cummins later negotiated to have his engines sold through the Sears Roebuck and Company catalog. However, an unforeseen loophole exploited by the farmers was Sears' return policy. Many farmers purchased the engines, used them for a season, and then returned them for a refund. Irwin, who was Cummins' major financial backer, was obviously not thrilled with the situation, and encouraged Cummins to continue to improve the design and reliability of the engines.

Rolling Showcase

Wanting to move beyond merely stationary, agricultural engines, Cummins was convinced diesels had great potential as powerplants for cars and trucks. To demonstrate their feasibility and efficiency, he installed one of his engines into a 1926 Packard Touring sedan, which he drove from Indiana to New York City with the intent of presenting it at the 1930 New York auto show. The car covered nearly 800 miles having used only 30 gallons of fuel -- an average of 26 mpg, an astoundingly efficient figure for the day. Because he was not officially registered as an exhibitor at the show, Cummins was turned away. The scenario repeated in nearby Atlantic City, where Cummins also showed the car. This time, he rented space across the convention hall to display the car and ended up being an even bigger attraction than most of the official exhibits at the show.

In 1931, Cummins staged another one of his famous public exhibition drives using a Marion truck equipped with one of his Model U engines. The truck drove from New York to Los Angeles, a distance of over 3000 miles in only 97 hours, more than two decades before the construction of the Interstate highway system.

After his successful truck demonstration run in 1931, Cummins followed up with another New York to L.A. run with a bus, which completed the journey in 91 hours, and achieved speeds up to 65 mph. The time proved faster than that of passenger trains of the day, and was a foreshadowing of the impact the interstate highway system would have in the decades to come.

Wanting to follow up his success with the Packard, in 1935 Cummins swapped a new lightweight six-cylinder diesel into an Auburn 851 sedan, which achieved an incredible for the time (and good even for today) 40 mpg. The car also reached an equally impressive top speed of 90 mph. Cummins hoped for a long-term relationship with the automaker, but Auburn went out of business only a year later.

Off To the Races

Realizing that racing was good publicity, Cummins entered a diesel-powered Duesenberg in the 1931 Indianapolis 500. The car qualified 17th and finished 13th. More remarkable than its respectable finish was the fact that it completed the entire race without a pit stop.

In 1934, Cummins returned to the Indianapolis 500 with two cars. One was a two-stroke diesel, and another was a four-stroke. Both utilized Roots-type superchargers. Although the two-stroke finished ahead of the four-stroke, it was smoking badly toward the last part of the race. After it had finished, the engine was so hot it seized the pistons to the block. From that day forward, Cummins has exclusively made four-stroke engines.

Cummins would go on to be an active participant in the Indianapolis 500 for decades, but a first place finish would elude Clessie and company. Undeterred, he entered a race car known as the Green Hornet for its distinctive paint job powered by a Model JS engine producing 340 hp in the 1950 race. The car qualified in 32nd place, and finished 29th. In 1952, Cummins took a first place qualifying position. The car ran strongly, but fell back during the course of the race, finishing 27th. A post-race inspection revealed that the turbocharger inlet on the car was clogged with rubber tire particles from the track. This would be the last time a diesel-powered race car competed at Indy.

Cummins retired from the board of directors in 1955, and went on to found his own company, Cummins Enterprises. He had been working on an experimental exhaust brake prior to his retirement, and later partnered with the Jacobs Chuck Company to create another icon of the diesel world, the famed Jake Brake exhaust brake. He later worked briefly for the Allison Aircraft Engine company in California. Clessie Cummins Sr. died in 1968. His son, Clessie Lyle Cummins, has written several books, including "The Diesel Odyssey of Clessie Cummins," a biography of his father and the company he founded.

Racetrack dominance eluded Cummins for many decades. The closest the company got to an Indy 500 win was the 1987 race, which Al Unser won in a Cosworth-powered car that used a turbocharger from Holset, a British manufacturer Cummins had acquired a decade earlier. Still, the company has retained dominance of the commercial diesel market, holding more than a 40-percent market share among Class 8 trucks for 2012 year to date.

Ram Tough, Cummins-Powered

Probably the biggest single factor that moved recognition of the Cummins name beyond the commercial truck sector was the company's partnership with Chrysler. By the mid-1980s, Chrysler was the only one of the Detroit Three automakers that did not offer a diesel option in its full-size trucks. General Motors was first, offering a diesel in its full-size trucks starting in 1978. Ford followed by offering a diesel sourced from International Harvester in 1983. Both of these engines were naturally aspirated V-8s and offered power comparable to their smaller-displacement gasoline counterparts with better fuel efficiency, but neither was particularly known for its torque output, characteristic of today’s modern turbodiesels .

Dodge was at an added disadvantage because it had one of the oldest truck designs at the time, with the basic styling dating back to 1972. The trucks received a refresh in 1981, when the Ram badge was first officially applied to the truck line, but they had no remarkable features in particular that stood out relative to newer competitors from General Motors and Ford. Dodge had previously offered a diesel in the Ram's D-series predecessor in 1978 in the form of a 4.0-liter naturally aspirated Mitsubishi inline-six. The engine was economical, but produced only 105 hp and 169 lb-ft of torque and was considered woefully underpowered. It was offered for just one model year. If Dodge was going to have a breakout hit, it was clear it needed to have something unique in the marketplace.

That standout feature would come in the form of the Cummins B-series six-cylinder engine. Cummins had already established a rock-solid reputation in the commercial segment and the company was ready to set the stage for its next level of growth. John Keele, Cummins' OEM marketing manager at the time, shared his insight on the early stages of development of the Cummins-powered Ram. "In early 1981, Chrysler formed Truck Operations to breathe new life into its truck division. During the same year, Cummins began marketing the new medium-duty engine line," Keele said. "Cummins then invited Chrysler to review its B series engine and its market research and engineering facilities.

In 1983, Cummins requested the engine compartment drawings to check fitment of the 5.9L B-series under the hood. From there, a running mock-up engine was shipped to Chrysler for use in a demonstration vehicle. After the technical review of the truck and the realization that there were no major issues, the project was kicked off formally."

Getting the B-Series into the Ram was no shade-tree engine swap. Because the Cummins engine was substantially longer and heavier than the 360 cubic-inch V-8 that was the Ram’s top engine and also produced substantially more torque, Dodge had to relocate the radiator support forward by 4 inches, use a larger radiator and add an engine oil cooler. Additional upgrades included a new electrical system, strengthened transmission (and new torque converter) better suited for the diesel's low-end torque, beefier rear axle, and upgraded transfer case and axle shafts for the four-wheel-drive models.

With potential output well above 200 hp and 500 lb-ft in commercial applications, the engine had to be detuned for use in the Ram. Taking into consideration emissions regulations, driveline strength and reliability, the final calibration for the 1989 Ram was 160 hp and 400 lb-ft of torque.

Although the horsepower was around the same as that offered by the naturally aspirated diesel V-8s at the time from GM and Ford, the torque figure positively crushed them. Because the engine was designed for much heavier-duty use than it would ever see in a pickup, it enabled the Ram to have a substantial payload and towing advantage over its rivals. The seeds of the diesel truck performance revolution had been planted.

Customer Focus

Don Altermatt, chief engineer of Diesel Products for Chrysler, has worked closely with Cummins since joining the company in 1994. From the early exploratory phases of the joint-venture between the two companies, the joint team has grown into a tight-knit collaboration of mutual respect and an intense focus on delivering the best product to the customer. "Our working relationship is very strong. We work from a technical perspective as if we're one company. The engineering teams meet daily, literally, and the senior management teams meet two to four times a year. We're pretty well-integrated and work very well together." Altermatt said. "What I personally enjoy from the perspective of the technical team is that it's all about the customer. It's all about protecting our joint customers. It's not about Cummins and it's not about Chrysler, it's about our customers."

This customer-driven model has guided the collaboration and development of products that deliver the attributes truck buyers want and need, which in the three-quarter and one-ton truck sector is primarily fuel economy and reliability. Although Cummins has very advanced R&D resources and capabilities, the team won't put an unproven product on the market. "Cummins is very much cutting-edge in its understanding and research. But it’s certainly not introducing technology for technology's sake," Altermatt said.

Cummins may not be a deliberate trend-setter, but its thorough focus on diesel development gave it an early edge in the HD truck segment. One example is the the multi-valve ISB engine introduced in 1998, three model years before competitors would offer the same feature. That same basic architecture has formed the basis for the engines offered in the Ram HD since, with the biggest change coming in 2007, with a displacement increase from 5.9 to 6.7 liters. This would bring output to a substantial 350 hp and 650 lb-ft of torque. Although Ford and GM were now in the ballpark in terms of power, Dodge and Cummins still enjoyed the best reputation for reliable, trouble-free operation.

1000 lb-ft Future?

With a figure that would have been inconceivable only a few years ago, the soon-to-be-introduced 2013 Ram HD models equipped with the Cummins and the Aisin six-speed automatic now produce 385 hp and a massive 850 lb-ft of torque. The idea that we would be approaching the 1000-lb-ft mark in a factory diesel pickup is mind-blowing, but we're now probably only a few years away from it. Whatever your truck brand preference is, we can thank Clessie Cummins and his tireless determination, and that fortuitous conversation between central Indiana and suburban Detroit for the diesel pickup performance scene we have today.

Further Reading:

Allpar.com – Clessie Lyle Cummins and Cummins Diesel Engines by Curtis Redgap

Allpar.com – Cummins 5.9 liter and 6.7 liter Inline Six-Cylinder Diesel Engines by Curtis Redgap

"The Diesel Odyssey of Clessie Cummins" by C. Lyle Cummins, Carnot Press, 1998

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