Four years after its initial launch in 2016, the High Power Density (HPD) engine brake from USA-based Jacobs Vehicle Systems has gone into production with a Chinese truck manufacturer, marking the first OEM application of the system.
The Sinotruk Yellow River tractor unit, designed and manufactured by China National Heavy Duty Truck company (CNHTC), will integrate the HPD technology in its 11- and 13-liter engines. The latest-generation Yellow River tractor unit, primarily intended for long-haul applications, was launched mid-September. Its manufacturer states it is the most technically advanced vehicle to wear the Yellow River badge, distinguished by its aerodynamic body design and low unit drag coefficient to 0.37.
CNHTC’s 11- and 13-liter engines, designated MC11 and MC13, are modular designs, with six cylinders and turbocharging, and have B10-rated (1.1 million-mile) reliability. The MC11 produces 453hp at 1,900rpm and 2,200Nm of torque at 1,000-1,400rpm; the MC13 produces 532hp horsepower at 1,800rpm and 2,500Nm at 1,000-1,400rpm. The HPD 1.5 stroke-equipped MC11 and MC13 engines are expected to be used in other applications.
Jacobs developed the HPD system in response to requests from global engine suppliers seeking high power density and a cost-effective alternative to the driveline retarder. It notes that the HPD helps meet the need for stronger engine braking due to fuel efficiency strategies which have reduced the natural retarding effects of vehicle wind resistance and friction from engine, drivetrain and tires. Jacobs claims the HPD can deliver performance comparable to a driveline retarder, up to one-and-a-half times the braking performance of traditional compression release braking over the engine’s entire operating range, and more than two times the braking performance at lower RPM.
The modular HPD system allows OEMs to select different versions of the technology depending on the application. This includes full 2.0 stroke, 1.5 stroke, standard compression release (CR) and future protection for Cylinder deactivation (CDA) and late intake valve closing (LIVC). The system works by using cylinder deactivation mechanisms to eliminate different main event valve lift events so a second compression release event per cam rotation can be achieved.