Quote:

I understand that there are many variable that dictate how much a pushrod will deflect such as overall length, width, wall thickness, valve spring pressure, valve train component weight, RPM of the engine, heat treatment, and construction material of the pushrod; but is there a general number to use for factoring actual valve lift when teh engine is operating? I know its complicated to say based on so many variables, but is it safe to say that a pushrod will deflect .020" regardless of all these variables? .030", .040". Lets say a 3/8 pushrod with a .080" wall thickness with an overall length of 7.75". Would it be safe to say at 650 pounds of open spring pressure that the pushrod will deflect a minimum of .020??....Or what as a minimum. Im not asking for absolutes, basically what as a minimum could be expected.



http://www.engineersedge.com/column_buckling/column_ideal.htm

No difference on the heat treatment. Almost all steels have the same modulus or within a few percent. The equation listed is not the exact equation because it's pinned, but still will give you an idea of the important parameters.

http://en.wikipedia.org/wiki/Buckling

Floyd Lippencott IV