1. What is Valve Spring Lift?

Valve spring lift is the maximum distance a valve spring can compress during engine operation. It's calculated as the difference between the installed height (IH) and the coil height (CH) of the valve spring.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( L \) — Valve spring lift (mm)
• \( IH \) — Installed height (mm)
• \( CH \) — Coil height (mm)

Explanation: The installed height is the length of the spring when installed in the engine, while the coil height is the length when fully compressed. The difference between these two values gives the maximum possible lift.

3. Importance of Valve Spring Lift Calculation

Details: Proper valve spring lift is crucial for engine performance and longevity. Insufficient lift can restrict airflow, while excessive lift can cause spring failure or valve float.

4. Using the Calculator

Tips: Measure installed height with the valve closed and spring properly seated. Measure coil height when the spring is fully compressed. Enter both values in millimeters.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical valve spring lift range?
A: Most performance engines have lifts between 0.400" to 0.600" (10-15mm), but this varies by application.

Q2: How does lift affect engine performance?
A: Greater lift typically allows more airflow, potentially increasing power, but requires careful spring selection.

Q3: Should I measure lift at hot or cold temperatures?
A: Measurements are typically taken at room temperature, but thermal expansion should be considered for precision applications.

Q4: What happens if lift exceeds spring specifications?
A: This can cause spring bind, excessive stress, and eventual failure. Always verify maximum safe lift for your springs.

Q5: How often should valve spring lift be checked?
A: During initial assembly and whenever valve train components are serviced or modified.