1. What is Valve Lift?

Valve lift is the maximum distance the valve moves away from its seat during the camshaft's rotation. It's determined by multiplying the camshaft lift by the rocker arm ratio.

2. How Does the Calculator Work?

The calculator uses the valve lift formula:

Where:

• \( \text{Cam Lift} \) — Maximum lift of the camshaft lobe (mm)
• \( \text{Rocker Ratio} \) — Ratio of the rocker arm (typically 1.5-1.7 for most engines)

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

3. Importance of Valve Lift Calculation

Details: Proper valve lift is crucial for engine performance. It affects airflow into and out of the cylinders, which directly impacts power output and engine efficiency.

4. Using the Calculator

Tips: Enter cam lift in millimeters and rocker ratio as a decimal (e.g., 1.6). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical rocker ratio for performance engines?
A: Most performance engines use ratios between 1.5:1 and 1.7:1, with some high-performance applications using up to 2.0:1.

Q2: How does valve lift affect engine performance?
A: Greater valve lift generally increases airflow and power potential, but must be balanced with valve spring capabilities and piston-to-valve clearance.

Q3: Can I measure cam lift directly?
A: Yes, using a dial indicator to measure the lobe's maximum height minus its base circle diameter.

Q4: What factors limit maximum valve lift?
A: Valve spring strength, piston-to-valve clearance, valve train stability, and the camshaft's profile all limit maximum practical lift.

Q5: Does rocker ratio affect valve timing?
A: While it primarily affects lift, rocker ratio can slightly alter the effective opening and closing rates of the valve.