Air compressor fill time ???

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Someone gave me an old Wayne vertical air compressor that I have had sitting in my shop for a year or two that i am just putting into service now. I believe that it is 60 gal but I don't know what the dimensions are for that or 80 gal.I have no way to know what the cfm of this compressor was when new.I believe that it is two stage as well but I'm not sure about that either. The pump has what appears to be one larger and one smaller cylinder side by side in one casting if that helps.A very large 1 1/5 hp GE 240 volt motor.It fills to about 90 lbs in 10 min and about 120-125 in 14 min.Does this fill time seem about normal for compressors of this size.If it is a 60 gal is there a process for me to calculate the cfm that it is producing now.Thanks,Ken
Reply:My 60 gallon compressor will go from 90 psi to 125 in right about a minute.  It's a single stage. I believe about 11 or 14 CFM.  It will fill from 0 to 125 psi in roughly 5 minutes.  I know it's not the same as what you have, but it will give you something to compare to.Sounds like your pump is worn out.  I would suggest either rebuilding it or replacing it.  I don't normally like harbor freight, but I have had good luck with the few replacement pumps I've dealt with from them.My name's not Jim....
Reply:Is Wayne the name on the compressor pump, or on the whole unit? If not the pump, do you see a model plate on the pump? It might just need to be rebuilt, and parts might be available.  Might be a problem with valves seating right; sometimes they have multiple reed valves. You might get some idea of its condition by removing the output line between the pump and the tank, then turning the pump by hand while plugging the output with a thumb, to see what kind of output volume and pressure it produces. The first thing I usually do with something like this is to take it apart and "see what makes it tick",  (really how well it's built and what the condition is) whether it needs it or not. Well, at least I used to....
Reply:Originally Posted by KGIORA very large 1 1/5 hp GE 240 volt motor.
Reply:Yes it is 1.5 hp (that was a typo). Tomorrow I will check, RPM, pulley sizes, pump model #, motor model, and anything else that may be needed just let my know.
Reply:That’s about right.  One atmosphere of pressure is about 14.7psi.  You added about 8.5atm’s of air to get to 125psi (125/14.7=8.5).  60 gal is about 8 cubic feet.8.5x8=68 cubic feetyou added 68 cubic feet in 14 min.68/14=4.8cfm4.8cfm is about right for 1.5hp.  The old girl is running fine.  Clean the filter and change the oil.  Bet it’s a nice sound to, ca-chug, ca-chug not RrRrRrRrRrRrRrRr!Last edited by OHT; 11-11-2010 at 10:02 AM.
Reply:Yup.  You've got a very small motor on a very large tank.Normally with a 60 gallon tank you would expect to see a 5hp motor, with even maybe a 7.5hp on an 80 gallon tank.My 7.5hp motor fills my 80 gallon tank to 175 in 3 or 4 minutes, but a 1.5hp would take a lot longer.Does your motor have an extremely small pulley on it, and is it a 1725RPM motor?Compressor pumps are often rated for a large range of horsepower, with the lower horsepower motors turning it at a slower speed, consequently generating less CFM.The upside to turning the pump slower, is that it is also quieter.
Reply:Yeh, very quite chug chug  alright. You can stand next to it and have a conversation without raising your voice.I will confirm after I get to the shop it could have been 1725, but I was thinking even 13?? maybe.So when larger motors are used they change pulley sizes to speed up the pump and increase the CFM ?I think that someone disconnected the unloader, I may be asking questions later about reconnecting it if i decide that its necessary but it seems to restart without any trouble at all.EDIT: Something I forgot to say is that if the starting pressure is at zero then for the first 60 seconds it sounds like it has a rod knock then at that point it has built enough pressure that it goes away and purrs. Any Ideas ??KenLast edited by KGIOR; 11-11-2010 at 12:02 PM.
Reply:Here is mine, Dont know anything about it. Was in my building when I bought it. 220 V single phase.  Takes it about 10-15 min to fill, and you can cut with the plasma for 10 min before it kicks on. It only runs for about 5 min untill it shuts back off. Same with air tools. We changed tires on the service truck and it never even came on. Great compressor. Attached Images
Reply:Some more details:Wayne compressor companyWayne pump model 378-vGE 1.5 hp spinning at 1725 rpm4.5" motor pulley15" pump pulley80 Gal tank10 min to 90 psi14 min to 120 psi Date on tank is 1964 (built the same year that I was)Do those numbers seem ok with those pulley sizes and motor rpm?If I use the numbers provided by OHT and replace with 80 gal and 120 psi come up with about 6.23cfm.Any particular compressor oil I should look for or stay away from?Thanks,KenLast edited by KGIOR; 11-11-2010 at 02:08 PM.
Reply:I needed to change the filter on my stand up compressor.The air in the compressor room becomes warm and I also wanted to move the intake to the other room.I ran the intake through the wall and put a "T" on it with 2 filters instead of one. My fill time went in half. Of course the air intake was as noisy as the compressor itself.
Reply:What kind of a filter had that much restriction?My filter is taken from a shop vac (one of those cylindrical jobs with rubber rings on each end).
Reply:It was just the little metal round canister which came with the air compressor.
Reply:Replacement canisters x2 on the other side of the wall:
Reply:Sounds like you're set!  Use regular air compressor oil unless you find a manual specifying something different.  Don't use synthetic oil unless your air lines are compatible.  Some people go so far as to modify their compressor intakes to take automotive air cleaners.   Sounds like you don't have any noise problems - if you do, mount the compressor feet on rubber isolators and duct your intake outside.  Most compressor noise is intake noise.  Don't forget to drain the water regularly!
Reply:If my pulley math is right the compressor is running at about 517 rpm. Most compressors range from minimum 400 rpm to maximum 1000 rpm at the pump. For example, if your compressor can do 1000 rpm (check the name plate for rpm) then I'd power with a 3 HP motor at 3450 rpm. This would spin the pump at 1035 rpm. This would double your CFM. You'd use the same pulleys.Of course running your compressor at 500 rpm means that it will last a long time, but it will cycle twice as long as it would if fully powered. Someone would likely run a larger pump at a lower speed in order to have a quiet compressor, longer life, cooler running machine. Very common in hvac applications. Also the lower speed will keep the air cooler and you'll likely have fewer moisture issues as it will drop out in the tank faster.I've attached the Quincy specs for reference. Note how the CFMs increase as the RPM (and HP respectively) increases. You might call around some pump shops and see if they can lookup the specs in an old book. Attached ImagesLast edited by forhire; 11-12-2010 at 03:46 AM.
Reply:I am a little confused...If you have a 2hp motor running at 1725 rpm and a 5hp motor running 1725 rpmhow would that change the cfm rating on the compressor pump?I have a Wayne pump with a 2hp running 1725 ish rpm on a 60 gallon tank.(This is a mixed bag compressor)  and it takes about 10 minutes to 140lbs.I am not sure if this is good or bad. Not real happy right now being it won't keep up with a die grinder. but if I am reading right I may want to look into a bigger motor.Can anyone give me any information on my pump? I would really appreciate the help.WayneModel 496LPHSerial 56778ThanksTed
Reply:Originally Posted by 4doorchevyI am a little confused...If you have a 2hp motor running at 1725 rpm and a 5hp motor running 1725 rpmhow would that change the cfm rating on the compressor pump?I have a Wayne pump with a 2hp running 1725 ish rpm on a 60 gallon tank.(This is a mixed bag compressor)  and it takes about 10 minutes to 140lbs.I am not sure if this is good or bad. Not real happy right now being it won't keep up with a die grinder. but if I am reading right I may want to look into a bigger motor.Can anyone give me any information on my pump? I would really appreciate the help.WayneModel 496LPHSerial 56778ThanksTed