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Wallace Rocker Arm Lift Formula:
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The Wallace Rocker Arm Lift calculation determines the actual valve lift in an engine by accounting for cam lift, rocker arm ratio, and spring compression adjustment. This is crucial for optimizing engine performance and valve timing.
The calculator uses the Wallace formula:
Where:
Explanation: The formula calculates the actual valve lift by multiplying cam lift by the rocker arm ratio and subtracting any spring compression adjustment.
Details: Accurate valve lift calculation is essential for engine tuning, performance optimization, and preventing valve-to-piston interference. It helps determine the actual airflow through the valves and overall engine efficiency.
Tips: Enter cam lift in inches, rocker arm ratio (typically between 1.5-1.8), and spring compression adjustment in inches. All values must be valid positive numbers.
Q1: What is typical rocker arm ratio range?
A: Most performance engines use ratios between 1.5:1 to 1.8:1, with 1.6:1 being common in many applications.
Q2: Why subtract spring compression adjustment?
A: Spring compression can slightly reduce the actual valve lift due to spring deflection under load, so this adjustment provides a more accurate measurement.
Q3: How does valve lift affect engine performance?
A: Higher valve lift generally increases airflow and power, but must be balanced with other factors like duration and lobe separation angle.
Q4: When is spring compression adjustment necessary?
A: This adjustment is particularly important in high-performance engines with stiff valve springs that may compress significantly under load.
Q5: Can this calculation be used for all engine types?
A: While the formula is generally applicable, specific engine designs may require additional considerations for accurate valve lift calculation.