The best way to determine which Alamo it is will be from the measurements. Measure the width of the main body, not including the end plates. From that we'll give you the answer. Most Alamo pumps will be rated not in CFM but in how many cow barn they were designed for. The choices I'm aware of are a 30, and a 50-75-100. On the 50-75-100 the difference is on the motor and the RPMs. For some reason they had no such marking on the pump. The pictures you show don't quite give the size well enough.
If it is an Alamo 30, you will get enough vacuum to run about 500-700 taps at 24-25" vacuum if you keep leaks to a minimum. One thing you will want is to open up the oil flow from the reclaimer. The original way to control that was to open the fitting where it re-enters the bearings on each end, and snap off a little of the hardened wire inside. That will increase the flow. However, far better is to buy some after market oilers and then you can get ones with a needle valve adjustment. Because the pumps were designed to run a 15" vacuum, to run much higher you need more oil flow. I like to adjust them to get 1 drip every 4-5 seconds if running above 17-18" vacuum.
Another thing you should do now, is remove the pulley end plate and pull the whole armature out to see if the vanes are badly warn or stuck in place. They need to be free for centrifugal force to hold them out against the outer surface. Also check the outer surface while it is open, if there is much scoring, have it machined to make it smooth. New vanes if needed are available from Wormuth Dairy & Refrigeration, in Morrisville, NY. Also some online supplies such as Hamby Dairy, (Fla?) likely others. Wormuth is among other things a Surge dealer.
Last edited by maple flats; 12-27-2020 at 10:45 AM.
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.