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FEATURE FOCUS: Rocker-Arm Math
The Camshaft Category in Dynomation-5 now includes a new, easy-to-use Rocker Math Calculator. This powerful tool will help you determine valve-motion, cam-timing, and power differences from changes in rocker ratio and valve lash.
Click on the Rocker Math Quick-Access™ button to open the calculator and determine how changes in rocker ratio and valve lash will affect cam timing, valve lift, and engine power. Depending on the cam installed and the acceleration-ramp rates, small changes in lash can have a significant affect on valve timing. For example, in the photo on the right, we've changed the intake lash from 0.020-inch to 0.025-inch. The Rocker Math Calculator has determined that increasing the lash by only 0.005-inch 1) reduces the intake lift by 0.005-inch (no surprise there), but, 2) since the lifter doesn’t start moving up the opening ramp until later in camshaft rotation, the intake valve open duration has been reduced by 4.3 degrees!
The Rocker Math Calculator is "smart" enough to base its calculations on the measured (for profile files) or determined (for 10-point cam timing) ramp rates of the currently installed camshaft. So, as the Acceleration Rates of the cam change, the changes in valve timing will also vary as lash and rocker ratio are changed.
Remarkably, you will discover that duration changes are the greatest for low-performance, low-acceleration-rate profiles. This almost counter-intuitive finding is clearly illustrated in the Rocker Math Calculator. The "secret" here is the fact that for low acceleration-rate cams, the lift-per-degree of cam rotation is low on the ramps, allowing lash changes to have the greatest influence on valve timing.
Rocker-Math Calculator in Dynomation-5 makes it easy to explore the effects of changing rocker-arm parameters. Use it to clearly show why maintaining known-best lash specifications is so important to peak performance.
Explore "True" Effects Of
Discover How Rocker Specs
New Rocker-Math Feature
The Easy-To-Use Rocker-Math Calculator clearly shows the effects of changes to lash or rocker ratio. After entering the original rocker specs in Dynomationi-5, CHANGED specifications are loaded in the Rocker Math Calculator. In this example, the intake rocker lash was changed from the recommended 0.020-inch to 0.025-inch. The 0.005-inch lash increase not only reduced valve lift by the same amount, but also reduced Intake Duration by 4.3 degrees! Press APPLY to perform a complete engine simulation with the new timing values to determine engine power differences.
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