US based global powertrain specialist, Cummins has revealed its new technology High Power Density (HPD) engine brake will be seen for the first time on its new on Cummins’ X10 engine, which is destined for heavy‑ and medium-duty use, in vocational, regional haulage and transit buses .
Cummins says its new X10 engine is part of its’ HELM “fuel-agnostic engine” lineup, where it replaces both the L9 and the X12 engines, not mention making up an important part of Cummins expanding confusion of acronyms..
The company reckons that the new 1.5-Stroke HPD engine brake on the X10, provides small and medium displacement engines with retarding power of larger engine displacement, claiming it can generate up to 40 per cent more supplemental braking force than traditional compression release braking at high engine speeds. The company also says that it can provide improvements of up to 100 per cent at lower RPM cruising speeds, supporting the commercial industry’s pursuit of better fuel economy and lower total cost of ownership.
According to Cummins, a conventional engine brake has one compression release (CR) and one brake gas recirculation (BGR) event for each of the engine’s cam rotations. It says its new 1.5-Stroke HPD, cylinder de-activation (CDA) mechanisms are used to eliminate the main exhaust valve events, allowing two CR events per cam rotation.
It says that a standard intake charge event is used to power the first CR event, however, for the second CR event, the power is achieved through the recirculation of exhaust manifold gases, without drawing air from the intake.
Cummins says it will offer two HPD engine brakes, a three-cylinder and a six-cylinder version, on its X10 to deliver coverage for customers formerly specifying Cummins L9 and X12 engines, respectively. The company claims the advanced brake offers up to 320 hp at 2300 rpm for the three-cylinder option, and up to 475 hp at 2300 rpm for the six-cylinder option.
Program leader of the X10 at Cummins, RaNae Isaak said, the HPD engine brake is both a unique and ideal braking solution for the wide displacement coverage of the new X10 engine, as well as the variety of duty cycles to be served.\
“Feedback from both OEM and end-user customers who have test-driven the new X10 with the HPD engine brake attest to its ability to offer the braking power of up to a 13-litre truck, via a 10-litre engine,” Isaak said
“In fact, many comment that the HPD engine brake is the most powerful braking solution in a vehicle they have ever driven,” he added.
The company says its HPD technology is part of its Valvetrain Technologies’ common modular design frame, which it says also allows other valve train technologies to be integrated, or removed, according to local market requirements, and has been developed in six other engine programs.
“Punching above its weight class, the HPD engine brake is an attractive, differentiating proposition for both engine and vehicle designers.
‘It’s a perfect match for the Cummins X10 engine because of the diverse number of applications, many that need high braking performance, and with the exhaust side of Cummins’ Cylinder Deactivation (CDA) already integrated as part of HPD, future applications will have a built-in bridge to the specification of full CDA for customer markets that demand a fuel-saving and emissions-reducing technology,” Isaak said.
“All that needs to be added are additional control solenoids and collapsing intake mechanisms to an already protected framework,” he said.
Two-Stroke and 1.5-Stroke HPD were announced in 2016 and 2018, respectively, by Jacobs Vehicle Systems, which was acquired by Cummins in 2022.
