Not Your Father’s Diesel Engine

Doosan Excavator

Significant enhancements to construction equipment power plants improve productivity

It’s likely no surprise that the diesel engine in your construction equipment today is a far cry from 30 years ago. Even significant updates in the past 10 years have changed diesel engines dramatically. What is under or behind a machine panel today is a sophisticated and connected diesel engine with less emissions.

Allow me to take a step back before Tier 4 was a common phrase in our industry. Diesel engines were still the lifeblood of construction equipment, including excavators, providing the muscle to do heavy earthmoving tasks. They may have supplied the power and torque needed to get the job done, but they certainly were not as productive as the diesel engines of today. Let me elaborate.

Major changes with non-road diesel engines in the last decade have involved the emissions reduction based on changes from Tier 3 to interim Tier 4, and finally to Tier 4. Construction equipment manufacturers have allowed systems to be designed more as a whole instead of a diesel engine just being a component of the system. In years past, the diesel engine itself could be mixed or matched. Now, the whole system is designed very tightly with the specs of the engines so that the hydraulic system or the transmission, depending on the type of equipment, are very much optimized to each other. The component optimization means owners and operators of construction equipment can enjoy enhanced machine productivity, especially better fuel efficiency, which can lead to a significant cost savings.

Ralph DiGiorgio, a contractor from the Northeast, says newer construction equipment uses much less fuel than previous generations. “We have a couple of big machines that are eating 75, 80 gallons of fuel a day,” DiGiorgio says. “New machines are burning a third less than that.”

Performance enhancements

One of the benefits of today’s more sophisticated diesel engines is how the engine performs. Advancements in more consistent fuel burn and more consistent fuel delivery systems combine to help maintain the optimal torque levels. In other words, while horsepower may be the same as it was a decade or two ago, the lugging ability of the engine – also known as the torque curve of the engine – has been optimized within that same horsepower level.

The advancement from mechanical to electronically controlled engines has brought a significant change to diesel engines. Electronically controlled engines are much more efficient. For example, there are multiple injection points for fuel within the combustion cycle to help maximize the fuel burn, as well as create the most power in every stroke of the cylinder within the engine.

Also, additions to high-pressure common rail systems with very fine droplets of fuel injected at multiple points within that combustion cycle have helped improve productivity, and at the same time reduce fuel consumption and reduce emissions.

Design changes

While the physical dimensions of today’s diesel engines haven’t changed, the space for the engine compartment has increased. Additional space is needed to accommodate the extra components necessary for diesel engines to meet strict emissions requirements. As a result, some machine envelope sizes have been widened or made taller to allow for the space required for the additional components.

In some cases, a larger engine compartment can impact the operator’s visibility to the area behind a machine, like a wheel loader. Many equipment manufacturers now offer rearview cameras to provide operators with assisting visibility to their surroundings.

Keep maintenance top of mind

It cannot be overstated how critical it is for owners and operators of construction equipment to properly maintain the machines. Skipping daily maintenance may lead to debilitating machine shutdowns – otherwise known as downtime – during the peak work season.

It goes without saying, operators must check the engine oil every day. It’s also a good idea to check for leaks around the filters and the oil pan. Operators should keep track of oil change intervals and change oil at the recommend interval. Service intervals are designed to make sure the engine and other components are kept working at optimal efficiency. As a reminder, oil is used to help keep the engine cool or running at its optimal temperature. It also helps disperse impurities that may be within the system. The oil is designed to help dissipate the impurities and the heat within the system. Today’s Tier 4-compliant engines require CJ-4 oil. It has been optimized for working with the high-pressure fuel systems.

Another good tip: Be sure there’s nothing major around the engine from a debris perspective.

Operators should also monitor components, like aftertreatment devices, to ensure they are well maintained. Those may include diesel particulate filters and knowing when the filters need to be replaced. The newest CJ-4 oils help to minimize issues with diesel particular filters. It’s also recommended to monitor the machine’s diesel exhaust fluid (DEF) system if the machine is equipped with selective catalyst reduction.

If an operator is lax with proper engine maintenance and aftertreatment systems, serious issues can develop. For example, the machine’s diesel particulate filter may start needing more frequent regeneration as well as replacement because of the trapping of oil additives. Over time, the machine may experience a reduction in engine performance because it has to work harder for the exhaust to breathe properly.

Operators should keep a supply of oil and oil filters on hand, especially if the machine is working at a jobsite for an extended time. Use genuine OEM filters that are designed for use with the engine. The OEM filters have the optimal filtering capacity as well as fluid flow within the filter, maximizing the ability for enough fluid to be flowing through the filter.

Air filters cannot be overlooked either. The air filters are designed for specific engines with an airflow window that is optimized for the engine. It helps maintain the proper flow of air into the engine to allow the combustion process to work properly.

Even though newer telematics management systems on construction equipment can alert customers and dealers about critical issues, operators should not depend only on these warning signals.

Diesel engines have come a long way in recent decades. They’re more productive for increased machine performance. They also require more care and maintenance checks to ensure the engines and the aftertreatment systems are working properly. Visit with your operators to make sure they understand the importance of properly maintaining the engines for peak performance this season.

This article was written by Ryan Johnson, Strategic Communications Manager for Two Rivers Marketing, which represents Doosan Infracore North American LLC. Headquartered in Suwanee, Georgia, Doosan Infracore North American LLC markets the Doosan brand of products that includes crawler excavators, wheel excavators, wheel loaders, articulated dump trucks, material handlers, log loaders and attachments. Doosan is a NUCA Sustaining National Partner.

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