Mathematical models of internal combustion engines and attached driveline systems are created and used to calculate and predict the torsional characteristics of the systems. This information is used to determine whether a torsional damper is needed and if so, the inertia, torsional spring rate and damping necessary for that damper. The OEM damper is simply not adequate for engine applications that have been changed from the basic OEM configuration. Examples of influential engine changes are:
- High HP — High RPM modifications
- Stroked cranks
- Supercharging or Turbocharging
- Large clutch or flywheel changes
- Different accessory drives (dry sump pumps, blower drives, etc.)
In these cases, BHJ recommends/creates a math model of the engine rotating components that can be used to run a full computer simulation of the engine at its new power and RPM levels. This model includes the damper and can be used to study the best combination of Inertia Ring value, Hub weight and Inertia, Damper tuning, Elastomer damping, and many other parameters. The computer results can be done in 2 stages and give:
- Holzer method study:
- Frequencies and RPM of the first, second and third mode orders
- Full torsion simulation:
- Torsion level predictions for all significant orders and modes
- Optional information can include:
- Damper Stress and heat loads
- Crank Main Bearing stress
- Vibrational Torque at any crank bearing location
This data and BHJ's damper design software allows a custom design to be created with very good confidence that the damper will perform properly "out of the box" when mounted on the modified engine. Data from the engine model is used to drive BHJ's design software and create the best damper for the application. Using current engine data allows a more refined design than historical experience that facilitates the Evolution Designs. Again, once the design numbers are decided, a CAD drawing or model is made to drive the CNC machining process.
Accessories, such as isolation pulleys, drive mandrels, ignition trigger wheels and other components are commonly required as part of damper projects.
Design and manufacturing services are also available for components such as these, either as part of a damper project, or separately.
Contact us to enquire about BHJ component development programs.
Click here to download the typical data questionnaire for initiating a Mathematical Torsional System Modeling quote or project.