Old Compressor

[Salem747]

Hi Everyone,

I bought an old Frankenstein compressor a couple of months ago. The guy had it mounted on an old water tank or something like that.

Anyway the pump looks quite old (50s or 60s) but it doesn't have much in the way of markings on it.

The guy had it hooked up to a 1725 rpm 1.5hp motor with a 3:10 pulley ratio so around 517 rpm.

Does anyone recognize this pump? It is quite distinctive in design, note the heat sink fins. I checked the patent number on the top and all it tells me is that it was patented by some guy named Webb in the 50s.

I was planning on making this into a portable compressor, but wanted to find out who made it and if parts will be impossible or just challenging.

It is fairly small but it is single stage, 2 cylinder.

 

[GeorgiaHybrid]

Pics???

 

[Salem747]

Sorry, I need to resize them, too big.

 

[tdkkart]

The top of the head looks exactly like a Campbell Hausfeld I used to own, had an aluminum head and cast iron crankcase and cylinders.

 

[isaac338]

Looks similar to a pump I am running now.. never did figure out who made it, although I did buy it attached to a Campbell Hausfeld tank (I think).

I've got it hooked up to either a 3 or 5 HP motor (don't remember), with a 3:10 ratio, 1750 rpm I think. Runs fine.

 

[Salem747]

Crankcase looks identical, even the casting of the feet is the same, just a different colour. I would guess yours is a bit older vintage, since the head and cylinder design is a bit simpler on yours. Mine is that metallic green that makes me figure 60s.

 

[isaac338]

Yep, I'd hazard a guess they're pretty common. The discharge fitting of my single cylinder which came with my compressor broke so I decided to rebuild this one and put it into service. I honed the cylinders and cleaned everything up; removed the valves and wirewheeled the rust and filth off them, and made new gaskets.

It's not perfect but it pumps my 60 gal tank up to 140psi faster than the single ever did!

If you decide to rebuild the valve plate, I think the tiny screws are 5/32 heads, but I had to put my socket in the lathe and turn a bit off the end because the screw heads are so thin they'd just spin inside the taper that's machined inside the very start of the sockets. Hard to explain, I hope you know what I mean.

 

[Salem747]

Did you have any trouble getting it apart and back together? I did a 2 stage Brunner and ended up breaking a ring. I was able to find new ones but it was a hassle.

How many CFM do you get? Do you remember the bore and stroke of the cylinders?

 

[cnc-me]

Its a Sears or Dayton Speedair (don't know who actually makes that pump though.)
Probably from late 60's early 70's.

 

[isaac338]

Did you have any trouble getting it apart and back together? I did a 2 stage Brunner and ended up breaking a ring. I was able to find new ones but it was a hassle.

How many CFM do you get? Do you remember the bore and stroke of the cylinders?

All I did was pull the valve plate and the cylinders - I didn't disassemble the rings, rods, or crank. I figured I'd run it and if it was spraying oil everywhere, take it back apart and source some rings. Luckily it didn't need them. One of my rods was actually a bit stiff on the crank, but I just needed a working compressor now and didn't want to go into details.. we'll see how long it lasts, I guess.

Disassembly was simple - the long bolts hold on the valve plate as well as the cylinders. Reassembly was a bit tricky trying to compress the rings and get the pistons in the bores - they're not tapered at the bottom. I didn't have a ring compressor handy, though.

I've no idea how to measure the CFM, but if I remember correctly the bore was 3".. didn't think to measure the stroke, sorry.

 

[kams1973]

That cylinder style and the greenish color is Speedaire. Yes parts are still available and simple pump to work on. There were two pumps that looked nearly identical. One has a bore of 2.75" and the other has a bore of 3". I'm thinking the stroke was 2". It would be perfect for a portable.

 

[Salem747]

A little quick & dirty math would suggest: (1.5")^2*pi*2"*2*700rpm=19,700cubic inches per minute, assuming perfect compression and ignoring temperature change, that is about 11cfm. That would work nicely for a portable.

The motor I have is 220V 1.5hp. Is 1.5hp the right size? I should look into a 110V 1.5hp.

I am thinking 20gallons in a horizontal wheeler.

 

[electrodude]

Like was already said, it's a Speedaire. I have one in storage waiting for me to get a place for it to live here, I put a 4HP 220V Dayton motor on mine, it's a good little machine. I believe the tank is a 40 gallon. This is the only picture I have of it, we were getting ready to move at the time...

 

[kams1973]

If the bore of the cylinders are 2.75, the motor you mentioned will work.

 

[Salem747]

I'm not interested in much more than 90-100psi so I shouldn't need 3hp. Wow, how big would a 3hp 110V motor have to be?

 

[Salem747]

Electrodude,

Think about testing that tank before you pump it up to 100psi with air. The way I have tested old tanks is to fill it up with water, then attach an enerpac and pump it up. It should hold to 150% of the rated pressure.

Better to fail it with a non-compressible fluid, way less energy involved.