[TheForge] Air Cylinder (actuators)

[DragonsWatch]

I once posted that I wanted to convert a LG. to air power.  After
reading the numerous posts and looking at several home built hammers, I
have come to wonder.  How large of a air actuator is required to operate
a 50# hammer?  One I have seen, (not in operation) one that looks to
have a 2" cylinder on it.  No one was available to ask about it at the
time so I could not get details on its performance.  I'll get more info
on it later as it is at a local college I have enrolled in.
    So, if a 2" cylinder can operate the ram, will a 4" cylinder operate
the 2" cylinder?  Is there a known ratio that is required here?  Is it
written down some where accessible?

Thanks,

Larry