Hydraulic 1

Hydraulic Dynamometer

AVL DynoSpecial

The AVL DynoSpecial Hydraulic Engine Dynamometer – a product of AVL ZÖLLNER MARINE is a cradled-mounted Load Unit with load cell for steady state and transient testing of marine combustion engines in the power range from 14.500kW to 140.000kW

AVL Approach

Our approach is based on complete flexibility in product configuration coupled with expert support to assist customers in specifying the solution that fits best. Load is varied by controlling the water outlet valve position and the optimal heat dissipation is ensured by controlling the water inlet valve position. 

Benefits at a Glance

  • Low investment costs per kW and Nm
  • Low infrastructure demands on testbed water supply (any stable pressure between 0.5-2 bar)
  • Available with one or two operating directions
  • Low moment of inertia combined with a compact, robust design
  • Unsusceptible to thermal stress even during agressive test cycles.

Technical Data



Product category Passive dynamometer
Technology Hydraulic
Design Cradle-mounted
Torque measurement Load cell
Power 14,500 – 140,000kW
Torque 150,000-14,000,000Nm
Speed 150 – 800rpm
Engine testing  
Steady-state testing
Dynamic vehicle simulation -
Drivetrain / dynamic +
mass zero simulation
Driveability simulation -
Passenger car emissions -
Heavy duty emissions -
Friction tests -
Component testing -
Formula 1 / Motorsports -
Turbine Test
Large Engine R&D
Large Engine EoL
Large Engine Emission
Powertrain / Driveline testing  
Endurance testing -
NVH Tests -
Dynamic motoring with
combustion simulation
Dynamic load with
tire simulation
Formula 1 / Motorsports -



The AVL Zoellner Marine hydraulic dynamometers function according to the Foettinger principle. The mechanical energy delivered by the test object is transformed into heat and transported by the water flowing through the dynamometer. There is a mixture of air and water level. The hydraulic dynamometer is controlled by the water fill level.

  • High permissible additional coupling weight
  • Suitable lubrication systems depending on the dynamometer range
  • Shaft with two coupling flanges as a standard feature
  • Internal components made of high-quality materials for extremely high performance with very low service requirements for the entire service life
  • Upgradeable from stand-alone to fully automated testbed