1. What is Valve Lift Calculation?

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

2. How Does the Calculator Work?

The calculator uses the valve lift formula:

Where:

• \( \text{Cam Lift} \) — Maximum lift of the camshaft lobe (mm)
• \( \text{Rocker Ratio} \) — Mechanical advantage of the rocker arm (typically 1.1-1.8)

Explanation: The rocker arm multiplies the camshaft's lift to achieve greater valve opening while allowing more flexible camshaft design.

3. Importance of Valve Lift

Details: Proper valve lift affects engine breathing, volumetric efficiency, and power output. Too much lift can cause valve train instability while too little restricts airflow.

4. Using the Calculator

Tips: Enter cam lift in millimeters and rocker ratio as a decimal (e.g., 1.5). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical rocker ratio?
A: Most production engines use ratios between 1.1:1 and 1.8:1. Performance engines may use higher ratios.

Q2: Does valve lift equal actual flow?
A: While related, actual airflow depends on many factors including valve size, port design, and lift duration.

Q3: Can you change rocker ratios?
A: Yes, many engines allow rocker arm upgrades to change valve lift without modifying the camshaft.

Q4: What limits maximum valve lift?
A: Piston-to-valve clearance, valve spring capabilities, and valve train geometry all impose limits.

Q5: How does this affect engine performance?
A: Increased valve lift generally improves high-RPM power but may reduce low-end torque if not properly matched to other components.