April 12, 2012
The upgraded DX350LC excavator from Doosan Infracore Construction Equipment America boasts an interim Tier 4-compliant, 281-horsepower, six-cylinder DL08K water-cooled diesel engine that has been optimized for use with a cooled exhaust gas recirculation system, diesel oxidation catalyst, and diesel particulate filter. The turbocharged 486-cubic-inch engine features a common rail design with direct fuel injection, electronic control, and four valves per cylinder.
Cooling system upgrades include two variable-speed hydraulic fans, which allow the engine and oil cooling systems to be controlled independently, improving fuel efficiency and providing a quieter operator environment. Additional upgrades include a swing torque increase of approximately 8 to 11 percent; a digging force increase of approximately 5 percent; a lifting capacity increase of approximately 2 percent; and a boom-up speed improvement of approximately 6 percent.
The company says it uses a variable geometry turbocharger (VGT) to increase boost pressure at lower engine RPMs. The VGT varies the amount of boost supplied to the engine to optimize combustion over the entire RPM range and allows the engine to generate a greater amount of torque in a wider band in the RPM range. The new closed-center main control valve with electro-hydraulic pump control is exclusive to the DX350LC and leads to an approximately 20-percent increase in efficiency of the main control valve for improved fuel economy.
The larger cab features enhanced ROPS protection, as well a height lever and tilting function for the seat. The cabin mounting mechanism features a thicker dampening plate, and a coil spring has been added to reduce cabin vibration 20 percent. The joystick angle has been reduced from 25 degrees to 19 degrees to provide a more ergonomic profile and decrease interference with the operator’s legs.