1. What is a Fuel Pump Size Calculator?

Definition: This calculator determines the required fuel pump flow rate (in gallons per minute) based on engine horsepower and fuel density.

Purpose: It helps automotive professionals and enthusiasts select the appropriate fuel pump for their engine's needs.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q_f \) — Fuel pump flow rate (gallons per minute)
• \( HP \) — Engine horsepower
• \( \rho_f \) — Fuel density (pounds per gallon)
• 0.055 — Conversion constant (based on BSFC assumptions)

Explanation: The formula calculates the minimum fuel flow required to support the engine's power output at wide-open throttle.

3. Importance of Proper Fuel Pump Sizing

Details: Correct fuel pump sizing ensures adequate fuel delivery under all operating conditions, prevents lean conditions, and supports optimal engine performance.

4. Using the Calculator

Tips: Enter the engine's maximum horsepower and fuel density (default 6.0 lb/gal for gasoline). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's the 0.055 constant represent?
A: It's based on a Brake Specific Fuel Consumption (BSFC) assumption of 0.5 lb/HP-hr with safety margin.

Q2: What's a typical fuel density value?
A: Gasoline is typically 6.0-6.3 lb/gal, while diesel is about 7.0 lb/gal.

Q3: Should I round up the calculated flow rate?
A: Yes, it's recommended to select a pump with 10-20% more capacity than calculated.

Q4: Does this account for forced induction?
A: No, for turbo/supercharged engines, multiply HP by 1.2-1.5 before calculating.

Q5: What about fuel pressure requirements?
A: This calculates flow rate only. Pressure requirements depend on fuel system design.