You want piston speed? The equation for piston displacement is h = (s/2) (cos(th) + sqrt(4 r^2-sin(th)^2) where h is the height, s is the stroke and r is the rod/stroke ratio. To get the speed you let th = w t and then differentiate. The expression is long. Then to get the max value you differentiate AGAIN and set the result equal to zero which tells you the time and you plug it in.
OR
You use the
interwebs to find
this.
Using stroke = 88mm = 3.46456" and rod = 150mm = 5.9055" I get vmax = 12876 feet/minute which works out to about 65 meters per second. But keep in mind that it's piston
acceleration that really kills parts. Read the "strokeornot" white paper to see how piston acceleration rises with rpms. You can find it with a quick google search. I suspect that you'll decide you were well into the crazy nasty high rpm range.