Piston Speed

Not Reviewed
Equation / Last modified by KurtHeckman on 2017/08/23 18:03
Rating
ID
KurtHeckman.Piston Speed
UUID
ae03d900-b3ad-11e4-a9fb-bc764e2038f2

The Piston Speed calculator computes the average (mean) speed of the piston based on the stroke length and the RPMs.piston rev.pngOne rev  

INSTRUCTIONS: Choose your units (e.g. inches or centimeters) and enter the following:

  • (s) Stroke length
  • (rpm)  Revolutions Per Minute of the engine.

Piston Speed: The calculator will compute the average piston speed in feet per minute.  However this velocity can be automatically converted to other speed units (e.g. meters per second).  For the Max Piston Speed, CLICK HERE.

The Math

   Inch Equivalences
FractionDecimalMils
1/16th0.062562.5
1/32th0.0312531.25
1/64th0.01562515.625

The Piston Speed equation calculates the mean velocity of the piston based on the cylinder stroke length and the RPMs.  The piston's speed of travel up and down the cylinder is always changing and actually comes to an instantaneous stop at both the upper and lower ends of the stroke at the beginning and end of a single revolution.  Therefor we can only calculate the average (mean) velocity based on RPMs.  In one minute, the pistons travel two times the stroke length times the number of revolutions (2 * Stroke * Revs).  Divide that by one minute and you have the mean piston speed.

Related Combustion Engine Calculators: 

  • RATIOS AND LENGTHS:
    • Bore (diameter): Compute the Bore Diameter based on the engine displacement, number of cylinders and the stroke length.
    • Bore Stroke Ratio: Compute the Bore Stroke Ratio based on the diameter of the bore and the length of the stroke.
    • Compression Ratio: Compute the Combustion Ratio base on the minimum and maximum displacements of the cylinder at the beginning (1-Induction) and compressed (3-Power) portions of the combustion cycle (see animation)
    • Displacement Ratio: Compute the Displacement Ratio based on the volumes at the beginning and end of the stroke.
    • Rod Length Stroke Ratio: Compute the Rod and Stroke Length Ratio base on the two lengths.
    • Stroke (length): Compute the Stroke Length based on the total engine displacement, number of cylinders and the bore.
  • VOLUMES:
    • Total Engine Displacement: Compute the Total Volume (displacement) of a Combustion Engine based on the bore, stroke and number of cylinders.
    • Engine Cylinder Volume: Compute the Volume (displacement) of a Engine Cylinder based on the bore and stroke.
    • Engine Cylinder Overbore Volume: Compute the Volume (displacement) of an Engine with an Overbore based on the stroke, bore, overbore and number of cylinders.
    • Rotary Engine Equivalent Displacement: Compute the Equivalent Volume of a Rotary Engine based on the swept volume and number of pistons.
    • Compression Volume (V2): Compute the Compressed Volume of a Cylinder when the piston is at the end of the stroke and the chamber is at its smallest (and most compressed) volume, based on the chamber, deck, crevice, chamfer, gasket, valve relief and dome/dish volumes.  This is the second volume (V2) in the Compression Ratio calculation.
    • Gasket Volume: Compute the Volume of a Gasket based on the inner and outer diameters and the gasket's thickness.
    • Deck Volume: Compute the Volume of a Cylinder Deck based on the deck height and the bore.
    • Crevice Volume: Compute the Volume of a Cylinder Crevice based on the piston diameter, cylinder bore and the crevice height.
    • Chamfer Volume: Compute the Volume of a Cylinder Chamfer based on the cylinder diameter and the chamfer height and width.
  • SPEEDS AND RPMS:
    • Max Piston Speed: Max Piston Speed based on stroke length and RPMs
    • RPMs: RPMs based on desired piston speed and stroke length.