I was kinda curious.

Does piston speed only depend on RPMs and stroke length? Does rod length affect speed, or piston acceleration? Or both?

What is the formula for calculating piston speed? What does it take into account? Stroke length, rod length, engine speed?

I would really like a formula to play around with.

Thanks in advance!

 

Average piston speed would only be effected by rpm and stroke.

 

I'm looking for a formula, will let you know when I find it.

-Tom


[Modified by il8apex, 1:33 PM 9/19/2001]

 

The graph is roughly a sine wave (~).

Anyway, I can't find a formula for piston speed at a given crank position, but I think you can use the following to determine max. piston speed for a given rmp. (Disclaimer: I just wrote this from memory, so please someone correct me!)

Use the crank stroke as "S", and "~" equals Pi because there isn't a Pi character on the keyboard! Dividing by 60,000 changes mm / minute to meters / second.

RPM x (~S)
----------
60,000

So, if your stroke is 81mm and you're running 7500rpm, your piston speed is 31.8086 meters/second. Hope this helps!

-Tom

 

Thanks....now if I can just figure how to graph that with my computer.......