Lashless Valvetrain with Engine Braking

Jacobs® Fulcrum Bridge and Spring Bridge Technologies enable the use of a hydraulic lash adjuster and an engine brake. 

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Rendering of Jacobs Fulcrum Technology Hardware

Hydraulic Lash Adjusters (HLA) technology has been desired on heavy-duty engines to eliminate the need to set and adjust lash as well as to optimize the cam design to enhance engine performance and efficiency.  Conventional engine brakes and HLAs are incompatible because the HLA will over-extend during braking causing possible valve-to-piston contact. Jacobs lashless technologies apply a reactive load to the HLA during an engine braking event to prevent overextension.


  • Enables the use of Hydraulic Lash Adjusters and a Jake Brake®
  • Eliminate the need to adjust valve lash
  • Increase vehicle uptime with reduced maintenance time and cost for operators
  • Reduce noise, vibration, and harshness (NVH) due to improved valve seating
  • Improves fuel economy and emissions
  • Cam design optimization improves performance and efficiency with optimized seating ramps
  • A suite of solutions available for any valvetrain
  • Cuts production time and cost at the manufacturer's assembly line
  • A simple, cost-effective solution without compromise
A detailed view of Jacobs Fulcrum Technology

Optimization of hydraulic cam design for improved performance and efficiency
A hydraulic cam design allows for optimization in the seating ramp areas which can lead to improvements in fuel economy and emissions. HLAs with Jacobs lashless technologies also allow for more consistent valve motions throughout all engine operating conditions.

Increases vehicle uptime with reduced maintenance time and cost for operators
Eliminating the need for setting lash in service will improve vehicle uptime for the operator, thereby improving the Total Cost of Ownership (TCO). This is especially important for applications where valvetrain access is challenging such as off-highway applications in dirty environments.

Cuts production time and cost at the manufacturer’s assembly line
Setting lash on the assembly line is often the bottleneck for engine production. This process is eliminated with the use of HLAs and the Jacobs Fulcrum or Spring Bridge.

Reduces noise, vibration, and harshness (NVH) with improved valve seating
HLAs allow for better control of the valve seating event, thereby reducing the NVH associated with the valvetrain.

Offers simple, cost-effective solutions without compromise
Jacobs lashless technologies such as Fulcrum Bridge or Spring Bridge are designed to work with conventional HLAs and various engine brake types.

Valve Lift

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Download this information package for more details and technical information about Jacobs’ Fulcrum Technology.