I have a Quincy 310, 1950 vintage. I have it mostly rebuilt & about ready to try but am somewhat puzzled by the unloader circuit.
Any pictures or info I find on a 310 show the hydraulic unloader, actuated by oil pressure. On this system, there seems to be only 1 air line going from the hydraulic valve to the unloader tower.
On mine, I have centrifugal weights on the crankshaft that close the unloader valve after it is up to speed. Air is allowed to flow from the tank to the unloader when it is stopped, pushing down on the diaphragm & deactivating the valve.
There is a tee on the unloader tower. The line on the other side goes to what I believe is a check valve. What I haven't figured out yet is how the unloader pressure gets bled off after the crankshaft valve closes. Or does this valve bleed the pressure off itself?
Is anybody familiar with this system?
Thanks,
Mark
Any pictures or info I find on a 310 show the hydraulic unloader, actuated by oil pressure. On this system, there seems to be only 1 air line going from the hydraulic valve to the unloader tower.
On mine, I have centrifugal weights on the crankshaft that close the unloader valve after it is up to speed. Air is allowed to flow from the tank to the unloader when it is stopped, pushing down on the diaphragm & deactivating the valve.
There is a tee on the unloader tower. The line on the other side goes to what I believe is a check valve. What I haven't figured out yet is how the unloader pressure gets bled off after the crankshaft valve closes. Or does this valve bleed the pressure off itself?
Is anybody familiar with this system?
Thanks,
Mark