air compressor setup

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Old 11-13-12, 12:17 AM
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air compressor setup

anyone knows the spec of my air compressor pump from what i know it came from an old military truck (Reo) and they say its U.S. made. I'm planning to buy a 1.5hp motor, will it work with this pump?
 
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Old 11-13-12, 12:23 AM
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If it's US made it would more than likely have a mfg stamp on it. You're going to need a dual belt pulley for that twin cylinder compressor. A 1.5 hp motor should run that. Did you try spinning the shaft ? Make sure it's not frozen.
 
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Old 11-13-12, 02:49 AM
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it has a stamp but it is already faded. i run it yesterday with a reconditioned 1/4hp motor single belt setup, i got 20psi but after a minute or so the motor starts to smoke. if i put on a 1.5 motor what cfm 90psi will i get?
 
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Old 11-13-12, 11:53 AM
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Can you figure out the total displacement of this thing? Looks like a single stage, two banger. I was told to use 1 hp for every 10 cubic inches of 1st stage displacement. Looks like you have a flat belt flywheel there, you'll need a motor pulley to match.
 
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Old 11-13-12, 12:57 PM
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I had a Bendix-Westinghouse air brake compressor that supposedly came off a Greyhound bus. I found quite a detailed write-up on it in an Army tech manual. Three cylinders, single stage and it was rated at 12 CFM. I'm guessing that pump you have would be about 8 CFM when turning in the neighborhood of 1200 rpm. Probably needs a solid two horsepower for that output.

Post several more pictures as there is something about the "rear" end of that pump that may be important.
 
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Old 11-13-12, 06:33 PM
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if i put a 2hp motor should i change the size of the pump pulley? why did my 1/4hp motor burned?






thanks mr. furd, mark and pj
 
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Old 11-13-12, 07:38 PM
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i wonder if the pump can produce 100 or 120 psi with a 2hp motor.
 
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Old 11-13-12, 10:46 PM
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A 1/4 hp motor was way undersized. That compressor maxed out that motor at 20psi. Can it produce 100-120psi with the 2hp motor. Probably. What would be the cfm. Hard to answer without knowing ALL the specs of that compressor and at this time we have almost none of the specs. You may also have to experiment with the size of the motor pulley to find the right mix of torque vs. speed.
 
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Old 11-13-12, 11:25 PM
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i look onto the stamp at the back of the pump and saw this code N-5480-D, search it in the net and found this site https://www.wbparts.com/rfq/4310-00-066-1031.html, problem is they don't have a pic. what will happen if i messed up the mix of torque vs speed, can it cause a serious problem with the pump or motor?

thanks for your time sir...
 
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Old 11-14-12, 01:29 AM
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According to the linked website that machine is rated at 7.4 CFM at 1250 rpm, pretty close to my guesstimate. !25 psi is pretty much the practical limit to the pressure developed because the volumetric efficiency of a single-stage compressor falls off pretty rapidly above 100 psi. That doesn't mean that you CAN'T run the pressure higher but what it DOES mean is the delivered CFM will fall off rapidly once you get above that magic 100 psi figure.

A very general "rule of thumb" for single stage, single acting reciprocating compressors is one horsepower for four CFM. There's the need for a two-horsepower motor. Don't try using a two-horsepower 3600 rpm "compressor duty" motor either; you need a true two-horsepower continuous duty motor running 1800 (+/-) motor.

Yes, you CAN use a smaller motor if you run the compressor slower. Running the compressor slower will decrease the CFM output.

Does this compressor have a self-contained pressure lubrication system? Some of the older air brake compressors (which I'm almost positive this is) required lubricating oil from the engine and also a crankcase drain back to the engine.
 
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Old 11-14-12, 02:26 AM
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i have no idea what S-CPLS looks like, the previous owner says he manually put oil on the pump but i can't find the oil cap. hope from this picture you can tell if it has a self-contained pressure lubricating system.
 
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Old 11-14-12, 09:59 PM
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If that compressor had a self contained oil reservoir - like a sump - there would need to be an oil level check area or a fill plug. I don't see one.

And yet...if it got its oil from the drive engine where are the oil lines connected ? Are there open fittings in the compressor that aren't shown in the pics ?
 
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Old 11-15-12, 01:05 AM
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I think you need to do a thorough job of cleaning this unit and then take at least a dozen (or more) clear, well-lit and in focus pictures from all angles. Definitely some close ups of any fittings. This could be a fine compressor but it definitely needs a fair amount of TLC.
 
 

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