1. What is Prop Pitch?

Prop pitch is the theoretical distance (in inches) that a propeller would move forward in one revolution if it were moving through a soft solid medium without slip. It's a crucial factor in determining a boat's performance.

2. How Does the Calculator Work?

The calculator uses the prop pitch equation:

Where:

• \( Speed \) — Boat speed in miles per hour (mph)
• \( Gear\ Ratio \) — Transmission gear ratio
• \( RPM \) — Engine revolutions per minute
• 1056 — Conversion factor to account for units

Explanation: The equation calculates the theoretical pitch needed based on your current speed, gear ratio, and engine RPM.

3. Importance of Proper Prop Pitch

Details: Choosing the correct prop pitch is essential for optimal engine performance, fuel efficiency, and achieving the desired boat speed without over-revving or lugging the engine.

4. Using the Calculator

Tips: Enter your actual boat speed in mph, your gear ratio (typically between 1.5:1 and 3:1 for most boats), and your engine RPM at that speed. All values must be greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: Why is 1056 used in the formula?
A: The 1056 factor converts mph to inches per minute (5280 ft/mile × 12 inches/ft ÷ 60 minutes/hour).

Q2: What is a typical prop pitch range?
A: Most recreational boat props range from 10-30 inches of pitch, depending on boat type and engine.

Q3: How does slip affect actual performance?
A: Real-world props experience 10-20% slip, meaning the boat moves less than the theoretical pitch would suggest.

Q4: Should I use GPS speed or speedometer reading?
A: GPS speed is more accurate for this calculation as it measures actual speed over water.

Q5: What if my calculated pitch doesn't match available props?
A: Choose the closest available pitch and consult with a marine mechanic for fine-tuning recommendations.