John Deere PowerTech PSL; The Four Cylinder Industrial Workhorse
Major Turbocharger and ECM Updates Bring Improved Power and Emissions to This Proven Workhorse
John Deere has a storied 180-year history building farming and industrial equipment. Deere continues to produce innovative farming products and other heavy apparatus that meet the Environmental Protection Agency’s highest standards.
The innovation truly shined in 1996, when the company introduced its PowerTech line of industrial diesel engines that met Tier 1 EPA regulations for off-highway equipment making more than 50 hp. The engines had no problem with the new standard. As emissions regulations continue to become more stringent, PowerTech oil-burners meet each new level thanks to the development of new technologies for the series. Advancements in exhaust filtration, fuel management, and turbochargers have been critical for keeping the engines viable at each new level.
This holds true for the newest unit in the line, the PowerTech PSL 4.5L, John Deere’s most powerful, efficient, and emissions-friendly 4.5L I-4 powerplant. It meets Tier 4/Stage IV emission requirements and is already prepped for Stage V standards, without the use of a diesel particulate filter. The variable-speed engine provides the highest output in its size group at 173 hp and 492 lb-ft of torque.
John Deere’s Integrated Emissions Control system plays a major role in the PSL’s ability to meet the stringent pollution requirements. With IEC, the exhaust gas recirculation system mixes cooled exhaust gases with incoming fresh air to lower peak combustion temperatures and reduce NOx. Downstream of this are the diesel oxidation catalyst and a selective catalytic reduction system. The DOC reduces carbon monoxide, hydrocarbons, and some particulate matter by reacting to the exhaust gases and converting them to carbon dioxide and water. Diesel exhaust fluid (and its high ammonia content) is used in the SCR system, mixed with the exhaust gases to further reduce NOx by converting it to nitrogen and water vapor.
The engine must also be very efficient. The PSL uses a two-stage “series” turbocharger system that provides more boost pressure than a single turbo. Having a greater amount of boost produces higher power density (the amount of energy transfer in a given space), improved low-speed torque, and improved high-altitude operation. Air is drawn through the airbox into a fixed-geometry, low-pressure turbo, which then feeds a variable-geometry, high-pressure ’charger for additional compression.
Upon exiting the variable turbo, the compressed air is routed through an air-to-air intercooler that reduces its temperature. Decreasing the charge-air temp helps lower emissions, while maintaining the engine’s low-speed peak torque and transient response time. The cool air then travels through the intake manifold and into the cylinder head. The head’s four-valve, cross-flow design improves airflow to the cylinders, increasing low-speed torque and transient response time.
The high-pressure, common-rail fuel system provides the correct air-fuel ratio by way of an updated engine control module. The new ECM handles the fuel-injection timing; controls the start, duration, and end of the injection events; and creates variable rail pressure, multiple injections, and higher injection pressures of up to 2.500 bar (36,000 psi).
The ECM manages both the engine and the aftertreatment system, and it has an option that allows it to be integrated with equipment or a vehicle in which the engine is installed. The PSL’s ECU has four times as much memory, double the amount of RAM and processing speed, and 40 percent more input/output capability than previous models.
SPECIFICATIONSEngine: John Deere PowerTech PSL 4045HFC06
Displacement: 4.5L (275 ci)
Engine Layout: I-4
Valvetrain: SOHC, 24-valve
Bore x Stroke: 4.17 x 5.00 inches (106 x 127mm)
Compression Ratio: 17.2:1
Head material: Cast iron
Block material: Cast iron
Piston material: Steel
Power: 173 hp
Torque: 492 lb-ft
Induction: Two-stage (“series”) fixed, and variable-geometry turbochargers
Exhaust: Cast-iron manifold
Cooling System: Liquid-cooled
Fuel System: High-pressure common-rail
Lubrication System: Wet sump
Lubrication Capacity: 16.8 quarts
Dry Weight: 1,257 pounds
Length: 34.3 inches
Width: 25 inches
Height: 44.5 inches