Bore Stroke Displacement Calculator

Engine Displacement Formula:

\[ D = \pi \times \left(\frac{b}{2}\right)^2 \times s \times n / 1000 \]

Engine Displacement (D):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Engine Displacement?

Engine displacement refers to the total volume of all the cylinders in an internal combustion engine. It is a key specification that indicates the engine's size and potential power output, typically measured in cubic centimeters (cc) or liters (L).

2. How Does the Calculator Work?

The calculator uses the engine displacement formula:

\[ D = \pi \times \left(\frac{b}{2}\right)^2 \times s \times n / 1000 \]

Where:

\( D \) — Engine displacement (cc)
\( b \) — Bore diameter (mm)
\( s \) — Stroke length (mm)
\( n \) — Number of cylinders
\( \pi \) — Mathematical constant pi (approximately 3.14159)

Explanation: The formula calculates the volume of a single cylinder (πr² × stroke) and multiplies by the number of cylinders, then converts from mm³ to cc by dividing by 1000.

3. Importance of Engine Displacement

Details: Engine displacement is a critical factor in determining an engine's power output, fuel efficiency, and emissions. Larger displacements generally produce more power but may consume more fuel.

4. Using the Calculator

Tips: Enter bore and stroke measurements in millimeters, and the number of cylinders. All values must be positive numbers with bore and stroke greater than zero, and cylinders between 1-16.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between bore and stroke?
A: Bore is the diameter of the cylinder, while stroke is the distance the piston travels from top to bottom within the cylinder.

Q2: Why divide by 1000 in the formula?
A: The division converts the result from cubic millimeters to cubic centimeters (1 cc = 1000 mm³).

Q3: How does displacement affect engine performance?
A: Generally, larger displacement engines produce more torque and power, but may have lower fuel efficiency compared to smaller engines.

Q4: What is a typical displacement range for different vehicles?
A: Motorcycles: 50-2000cc, Cars: 1000-6000cc, Trucks: 4000-15000cc, with variations based on vehicle type and purpose.

Q5: Can this formula be used for any engine type?
A: This formula works for most piston engines including inline, V, flat, and rotary engines, but may need adjustment for unusual cylinder configurations.