1. What is Rocker Arm Lift?

The rocker arm lift determines how much the valve opens based on the camshaft profile and rocker arm ratio. It's a crucial measurement in engine performance tuning and valve train design.

2. How Does the Calculator Work?

The calculator uses the rocker arm lift formula:

Where:

• \( \text{Cam Lift} \) — Maximum lift of the camshaft lobe (mm)
• \( \text{Rocker Ratio} \) — Ratio of the rocker arm (typically 1.5-1.8 for performance engines)

Explanation: The rocker arm multiplies the camshaft's motion to create greater valve lift than the cam lobe alone would provide.

3. Importance of Valve Lift Calculation

Details: Proper valve lift calculation is essential for engine performance, preventing valve-to-piston contact, and ensuring optimal airflow through the engine.

4. Using the Calculator

Tips: Enter cam lift in millimeters and rocker ratio as a decimal (e.g., 1.7). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical rocker ratio?
A: Most production engines use 1.5:1 to 1.7:1 ratios, while performance engines may use 1.8:1 or higher.

Q2: How does valve lift affect performance?
A: Greater valve lift generally improves high-RPM power but may reduce low-end torque if excessive.

Q3: Can I increase valve lift by changing rocker ratio?
A: Yes, but ensure your valve train can handle the increased stress and check for piston-to-valve clearance.

Q4: What's the relationship between duration and lift?
A: Duration is how long the valve stays open, while lift is how far it opens. Both affect engine performance.

Q5: When should I measure actual valve lift?
A: Always verify calculated lift with actual measurements, especially when modifying engines or using non-standard components.