1. What is Mean Piston Speed?

Mean Piston Speed (MPS) is the average speed of a piston in a reciprocating engine as it moves from top dead center (TDC) to bottom dead center (BDC) and back. It's an important parameter for engine design and performance analysis.

2. How Does the Calculator Work?

The calculator uses the MPS formula:

Where:

• \( MPS \) — Mean Piston Speed (m/s)
• \( stroke \) — Piston stroke length (meters)
• \( RPM \) — Engine revolutions per minute

Explanation: The formula calculates the average speed by considering the total distance traveled by the piston (2 × stroke) in one minute, then converting to seconds.

3. Importance of MPS Calculation

Details: MPS is crucial for engine design as it affects engine durability, valve timing, and performance characteristics. Higher MPS values typically indicate higher engine stress.

4. Using the Calculator

Tips: Enter stroke length in meters and engine RPM. Both values must be positive numbers for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical MPS range for engines?
A: Passenger car engines typically have MPS of 8-15 m/s, while high-performance engines may reach 20-25 m/s.

Q2: Why is MPS important for engine design?
A: MPS affects piston ring sealing, bearing loads, and inertial forces - critical factors in engine reliability and longevity.

Q3: How does MPS relate to engine power?
A: While higher MPS can indicate higher potential power output, it also increases mechanical stress and wear.

Q4: What's the difference between MPS and instantaneous piston speed?
A: MPS is the average speed, while instantaneous speed varies throughout the stroke, reaching maximum at mid-stroke.

Q5: Does MPS affect engine breathing?
A: Yes, higher MPS increases intake and exhaust gas velocities, affecting volumetric efficiency and scavenging.