The company’s legacy as an innovative leader continues with the introduction of its new ACERT engine emissions technology.
By Jim Brightly
Beginning this month and continuing in the July and August issues, FMC will highlight each of the three major diesel engine manufacturers “” Caterpillar, Cummins, and Detroit Diesel “” that supply power plants for the ever-growing type A diesel-pusher motorhome market.
Unless you own a diesel motorhome propelled by one of the company’s big yellow power plants, when you hear the word “Caterpillar” you probably envision large, yellow machinery plowing the ground for seeding, prepping it for buildings, or smoothing it for a freeway. That’s because Caterpillar Inc. gained much of its reputation during the past 79 years for the heavy agricultural, construction, and mining equipment it produces. What may come as a surprise to some is that, for much of that time, the company also has been a leading manufacturer of diesel engines, both for its own products and for the original-equipment manufacturer (OEM) market, which includes trucks and motorhomes.
Caterpillar currently is based in Peoria, Illinois, but the company’s history actually began in California and involved two separate families “” the Holts and the Bests “” who moved to the Golden State and found their niches in the agriculture and timber industries.
In 1883 New England native Charles Holt opened the Holt Manufacturing Company “” a wheel-and-carriage body manufacturing business that evolved to specialize in farming machinery “” in Stockton, California.
Shortly after the turn of the century, the company faced a major dilemma. Their tractors, equipped with heavy steam traction engines, often would sink and become mired in the soft soil, making them useless until they could be dug out. To resolve this problem, Charles’ son, Benjamin, came up with the brilliant idea of replacing the wheels with tracks. This innovation was given the nickname “Caterpillar,” because it reminded its developers of a caterpillar’s method of movement.
During World War I, Holt crawling tractors were used to haul artillery and pull long trains of freight wagons along unimproved roads, introducing the rest of the world to this type of propulsion. The company also was responsible for producing the first tank made in the United States.
Daniel Best left his family’s farm in Iowa in 1859 to take up residence in California, where he began manufacturing agricultural machinery for the farm and timber industries under the Best Tractor Company name. The enterprise was bought by Benjamin Holt in 1908. After the acquisition, Daniel’s son, C.L. Best, was made plant manager of Holt’s Stockton facility. Two years later, though, C.L. Best left to resurrect his father’s company, naming it the C.L. Best Gas Traction Company. Although his company was smaller than Holt’s, C.L. Best was able to compete in the rapidly growing Western market. In 1925, these two successful companies merged to create the Caterpillar Tractor Company, with C.L. Best as its CEO.
Today Caterpillar Inc. is a global manufacturer of construction, mining, and agricultural equipment, as well as engines for trucks and motorhomes, ships and boats, locomotives, and stationary applications. With reported annual sales and revenues of nearly $22.8 billion in 2003, Caterpillar is one of 30 companies included in the Dow Jones Industrial Average index, which is used as a bellwether of American business performance.
A “New” Engine
During the late 1800s and early 1900s, most agricultural tractors were equipped with heavy steam engines that were inefficient and labor-intensive (a crew of seven men was required to operate some of the machinery). Holt Manufacturing first turned to gasoline-powered engines that were significantly lighter and required less manpower. But after the 1925 merger, C.L. Best began looking for a better power source for the company’s equipment and found it in the diesel engine.
At the time, diesel engines were bulky, heavy, and, for the most part, stationary. But they did offer the advantages of less maintenance, longer life spans, and lower fuel consumption. The company tried to adapt several existing diesels to fit its equipment, with little success. So they invested more than $1 million to develop a lightweight mobile diesel engine that was suitable for use in tractors. In 1931, the D9900 engine was introduced as the first mobile diesel Caterpillar commercial engine and it became the power plant used on the popular Diesel 60 tractor. (The prototype engine, nicknamed “Old Betsy,” is now displayed at the Smithsonian Institution in Washington, D.C.)
From that point, it was only natural for Caterpillar engines to begin showing up on the road. In 1939 Caterpillar introduced its first diesel engine designed specifically for trucking: the six-cylinder D468, rated at 90 horsepower at 1,800 rpm, which is said to have been capable of running all day on $5 worth of fuel (in 1939 prices).
Truck engine production was halted during World War II, as the company dedicated its resources to building tractors and other machinery for the military. Following the war, the company established a dedicated engine facility and engine division, which began an influx of new models and technology that would continue through the remainder of the 20th century.
Cleaner, More Efficient Engines
When stringent emissions regulations went into effect in 2002, Caterpillar developed a new technology called ACERT to reduce emission levels for its on-highway engines. Improved air management is the foundation of this technology. Caterpillar’s on-highway power plants employ one or a series of turbochargers to force cool, clean air into the combustion chamber to lower the combustion temperature and reduce the formation of oxides of nitrogen.
For the C13 ACERT engine, air volume control through the engines is accomplished by variable valve actuation, which is said to result in more complete combustion and better fuel economy at various engine speeds and loads. Monitored and controlled by electronics, valve positions and fuel injection events are optimized based on engine demands to meet the stringent emissions levels.
The C7 and C9 engines utilize the highly flexible hydraulic electronic unit injector (HEUI), while the C13 uses mechanically actuated, electronically controlled unit injection (MEUI). Both systems are designed to provide a split injection fuel delivery to the combustion chamber, which means that a tiny amount of fuel is injected at the beginning of combustion, followed a millisecond later by a larger volume of fuel.
Caterpillar offers three in-line six-cylinder engines for the motorhome industry: the C7 (7.2-liter displacement), the C9 (8.8-liter displacement), and the C13 (12.5-liter displacement), all of which use ACERT technology.
The turbocharged C7 is the smallest and the most widely used engine on Caterpillar’s list of motorhome power plants. It provides a wide range of horsepower ratings for a corresponding range of chassis sizes (300, 330, and 350 horsepower at 2,400 rpm; 860 pound-feet of torque at 1,440 rpm). Based on the established 3126E power plant, which is no longer in production, this engine is available with either a shallow oil sump (22 quarts) or a deep sump (30 quarts) with an oil change interval of 11,000 miles/one year or 15,000 miles/one year, respectively.
The C9 is the mid-range engine in the Caterpillar lineup. It combines a single turbocharger, a heavy-duty crankshaft, and midsupported wet-liners to produce improved performance, better throttle response, and increased fuel economy. Horsepower ratings range from 350 to 400 at 2,100 rpm; torque rating 1,150 pound-feet at 1,400 rpm. The C9 holds 33 quarts of oil with a change interval of 20,000 miles or one year, whichever comes first.
The C13 continues the reliability legacy established by the C12 engine, which has been dropped from the lineup. The C13 uses dual in-series turbochargers and a higher compression ratio to provide improved breathing ability and better responsiveness. The engine is rated at 525 horsepower at 2,100 rpm; 1,650 pound-feet of torque at 1,200 rpm. The C13 holds 36 quarts of oil with a change interval of 20,000 miles or one year, whichever comes first.
From the California farm fields and timberlands of more than a century ago to wherever people need power today, Dr. Rudolf Diesel, father of the diesel engine, would be proud of the progress Caterpillar has made with his invention.
Caterpillar Inc., 100 N.E. Adams St., Peoria, IL 61629; (309) 675-1000; www.caterpillar.com.
Engine Horsepower@rpm Torque (Pound-Feet@rpm)
C7 300, 330, 350 @ 2,400 860 @ 1,440
C9 350, 370, 400 @ 2,100 1,150 @ 1,400
C13 525 @ 2,100 1,650 @ 1,200