1. What is Prop Pitch?

Prop pitch is the theoretical distance (in inches) that a propeller would advance in one revolution if it were moving through a soft solid medium without slip. It's a crucial parameter for boat and aircraft propeller performance.

2. How Does the Calculator Work?

The calculator uses the prop pitch equation:

Where:

• \( Speed \) — Vehicle speed in miles per hour (mph)
• \( RPM \) — Engine revolutions per minute (rpm)
• \( Gear\ Ratio \) — Transmission gear ratio (dimensionless)
• \( Slip \) — Propeller slip factor (0 to 1, where 0 = no slip)
• 1056 — Conversion factor (inches per mile / minutes per hour)

Explanation: The equation accounts for the relationship between engine speed, gear reduction, and actual vehicle speed, while considering propeller slip in water or air.

3. Importance of Prop Pitch Calculation

Details: Proper prop pitch selection is essential for optimal engine performance, fuel efficiency, and preventing engine over-revving or lugging.

4. Using the Calculator

Tips: Enter speed in mph, RPM while at that speed, gear ratio, and estimated slip (typically 0.10-0.15 for boats). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical slip factor for boats?
A: Most boats have 10-15% slip (0.10-0.15), though high-performance boats may have higher slip.

Q2: How does pitch affect performance?
A: Higher pitch increases top speed but reduces acceleration. Lower pitch improves acceleration but limits top speed.

Q3: What's the 1056 conversion factor?
A: It converts mph and rpm to inches (63360 inches per mile / 60 minutes per hour = 1056).

Q4: Can I use this for aircraft propellers?
A: Yes, though aircraft typically use knots for speed and may have different slip characteristics.

Q5: What if my calculated pitch doesn't match standard prop sizes?
A: Choose the nearest available pitch or consult with a propeller specialist for custom options.