Mean Piston Speed Calculator

Enter the stroke and engine RPM to get the average speed of the piston in feet per minute and meters per second. Stroke can be in inches, millimeters or centimeters.

How to calculate mean piston speed

Feet per minute = stroke (in) × RPM ÷ 6 Meters per second = stroke (mm) × RPM ÷ 30,000

The piston travels the length of the stroke twice for every turn of the crank, once down and once up. Multiplying the stroke by 2 and by the RPM gives inches per minute, and dividing by 12 gives feet per minute, which simplifies to stroke × RPM ÷ 6. The metric version does the same with millimeters: 2 × stroke × RPM gives millimeters per minute, and dividing by 60,000 gives meters per second.

Example: a 350 at 6,000 RPM

A small-block Chevy 350 has a 3.48-inch (88.4 mm) stroke.

3.48 × 6,000 ÷ 6 = 3,480 feet per minute 88.4 × 6,000 ÷ 30,000 = 17.68 meters per second

How stroke changes piston speed

Piston speed goes up in direct proportion to stroke. A 383 stroker, with a 3.75-inch stroke, runs 3,750 feet per minute at 6,000 RPM, about 8% more than the 350. To keep the same 3,480 feet per minute, the 383 would have to stay at about 5,570 RPM. The displacement calculator shows what the longer stroke adds in cubic inches.

Piston speed of Chevrolet Performance crate engines

Each engine at the maximum engine speed listed on its Chevrolet Performance spec sheet:

Engine	Stroke	Max engine speed	Mean piston speed
350/290 HP	3.48 in	5,100 RPM	2,958 ft/min (15.03 m/s)
350 HO	3.48 in	5,100 RPM	2,958 ft/min (15.03 m/s)
SP350/357	3.48 in	5,600 RPM	3,248 ft/min (16.50 m/s)
Ramjet 350	3.48 in	5,600 RPM	3,248 ft/min (16.50 m/s)
ZZ5 350	3.48 in	5,800 RPM	3,364 ft/min (17.09 m/s)
454 short block	4.00 in	5,500 RPM	3,667 ft/min (18.63 m/s)
LS3	3.622 in	6,600 RPM	3,984 ft/min (20.24 m/s)
ZZ427/480	3.70 in	6,500 RPM	4,008 ft/min (20.36 m/s)

Stroke and maximum engine speed from the Chevrolet Performance spec sheets for the 350/290 HP, 350 HO, SP350/357, Ramjet 350, ZZ5, 454 short block, LS3 and ZZ427/480. Piston speed is calculated with the formula above.

Mean and peak piston speed

Mean piston speed is an average. The piston stops at top and bottom dead center and moves fastest partway through the stroke, so its peak speed is higher than the mean. Mean piston speed is still the easy number to compare between engines, because it only needs the stroke and the RPM.

To find the RPM your engine turns at a given road speed, use the engine RPM calculator.

Frequently Asked Questions

How do you calculate mean piston speed?

Multiply the stroke in inches by the RPM and divide by 6 to get feet per minute. For meters per second, multiply the stroke in millimeters by the RPM and divide by 30,000.

What is the piston speed of a 350 at 6,000 RPM?

With its 3.48-inch stroke, a 350 at 6,000 RPM has a mean piston speed of 3,480 feet per minute, or 17.68 meters per second.

What piston speed do factory crate engines run?

At the maximum engine speeds on their spec sheets, Chevrolet Performance crate engines range from 2,958 feet per minute for the 350/290 HP at 5,100 RPM to 4,008 feet per minute for the ZZ427/480 at 6,500 RPM.

Does a longer stroke increase piston speed?

Yes, in direct proportion. A 3.75-inch stroke runs about 8% faster than a 3.48-inch stroke at the same RPM.

What is the difference between mean and peak piston speed?

Mean piston speed is the average over the whole stroke. The piston stops at each end of the stroke and moves fastest in between, so its peak speed is higher than the mean.