That is at 16GPM.
A 16 GPM 2 stage pump would drop to 4GPM (8horse power) at higher pressure. A 16 GPM single stage pump would need 16 HP @1500PSI, and 32HP @3000PSI.
It would take a strong frame to hold it, but what a splitter!!
True, but:
A 2 stage pump only slows down when pressure rises above the set point (not sure excactly, but if we use 500PSI, an 8" will develop 12 tons of pressure before it even kicks down to the low/speed high pressure side.) My guess is most of his splits will never make it shift down.
I'm just guessing here, but I think your stroke is probably only what you have, maybe a couple inches more are possible, but in a cylinder that size, there's a pretty substantial piston on the end of the rod. The extra length on the rod is likely just to get the needed length for it's original application.
BTW, I run a 7" x 28" cylinder on mine with a big single stage pump run off a tractor PTO. It ain't fast, but it doesn't stop either. My cycle time is close to 20 seconds full extend and retract, probably average 12-15 while splitting (not running full length).
As Kevin mentioned, it needs big valves and hoses (read $$$) to move this kind of oil. Mine are 1" on the pressure side, with a 1.75" return line.