1. What is Cam Lift?

Cam Lift refers to the maximum displacement of the camshaft lobe from its base circle. It determines how much the valve opens when multiplied by the rocker arm ratio.

2. How Does the Calculator Work?

The calculator uses the cam lift formula:

Where:

• Valve Lift — Maximum valve opening distance (mm)
• Ratio — Rocker arm ratio (decimal value)

Explanation: The formula calculates the necessary cam lobe lift to achieve a specific valve lift given a particular rocker arm ratio.

3. Importance of Cam Lift Calculation

Details: Proper cam lift calculation is essential for engine builders to ensure correct valve timing, prevent valve-to-piston contact, and achieve desired engine performance characteristics.

4. Using the Calculator

Tips: Enter valve lift in millimeters and rocker ratio as a decimal (e.g., 1.5:1 ratio is entered as 1.5). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

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

Q2: How does cam lift affect engine performance?
A: Higher cam lift generally increases airflow at high RPM but may reduce low-end torque and require stronger valve springs.

Q3: What's the relationship between cam lift and duration?
A: While related, lift and duration are separate specifications. Lift determines how far the valve opens, duration determines how long it stays open.

Q4: Can I measure cam lift directly?
A: Yes, with a dial indicator measuring the cam lobe's base circle to peak height, excluding any lifter preload.

Q5: What factors limit maximum cam lift?
A: Valve spring capabilities, piston-to-valve clearance, rocker arm geometry, and lifter/pushrod strength all impose practical limits.