Cummins has confirmed wedge capsule engine braking for its 2027 X15, X10, and B6.7 Octane HELM engines, marking its first mechanical braking system and cutting response time by up to 60% against conventional compression release designs. The X15 drops below 100 milliseconds, from 300–350 milliseconds in slab brake designs.

The two-step mechanism limits load transfer to approximately 30% of full actuation force on partial engagement, guarding against a failure mode common to single-actuation pin lock systems. It also eliminates hydraulic compliance, removing the lift-loss variable hydraulic systems must offset through cam lift.

Gabe Roberts, Director of Product Development, Cummins Valvetrain Technologies, said: “The capabilities unlocked by wedge capsule technology, and particularly the two-step activation mechanism, are key to Cummins launching its first-ever mechanical braking system for these Cummins engines. OEMs have a strong requirement for speed of brake activation, while solutions that bring faster engine brake-assisted gear shifting are also highly sought after.”

For OEMs with engine brake-assisted gear shifting, the faster response reduces speed droop and the re-acceleration fuel penalty. No crank angle-based control is required, simplifying OEM integration.

The X15 offers the highest total braking power in its class; on the X10, two capsules handle both cylinder deactivation and braking. The B6.7 Octane is Cummins’ first gasoline engine application.

Source: Cummins