More CFM from my compressor?

[Mikeyworks]

I have an older Kellogg-American compressor (Model 321 TV) that is currently rated at 3.5/8.8 CFM according to the manufacturer.

I want to increase the available CFM so I can run some of my tools longer (cut off wheel, DA sander, etc.)

Can I do this just by putting on a bigger motor to spin the compressor head faster? I really don't have the funds to replace the whole unit right now, but I am looking for a corrective measure for the meantime.

Thoughts? Comments? Concerns? Derisive Remarks?

Thanks,
mikey

(my compressor for reference)

http://i2.photobucket.com/albums/y38/Mikeyworks/tools/P7102702.jpg

 

[Charles (in GA)]

Go over to the Yesterdays Tractor discussion groups, the Tool group specifically.

www.ytmag.com

and ask this question. There is a guy XRogerX who has been working professionally in the compressor repair business for many years and is a guru on most of the older compressors. He will be able to tell you.

Just title your post something like "Compressor question for XRogerX"

Charles

 

[Roospike]

How much are you willing to spend ?

also : I see 80 + 120 tanks on ebay all the time for $100-$300.
This will give you extra "time" to run your tools but you will have to wait for the whole set up to pump up again.

Some pumps can take a larger motor on the same pump to give extra CFM but you would have to find out for sure if your pump can take the extra power.

 

[mike944]

well, the first step is definitely finding out whether your pump can handle more CFM without overheating, or other damage.

Beyond that, it's not quite as simple as a "bigger motor" You don't just need more power, you need more speed. You could put a 100hp motor on your compressor, but if you still turn it at the same speed, you're going to get the same CFM. You'll either need a larger HP, AND higher speed motor, or a larger HP motor of the same speed, with different pulleys, and belts to change the speed of the pump. Most AC motors come in 2 speeds 1725rpm, and 3750rpm. You'll need to figure out what speed you have, and that will affect how you need to do this, and what stuff you need to buy.

In my opinion, i wouldn't try to gain too much. your pump was designed with a specific speed, and HP in mind. Most well-designed things have some tolerance for overload designed in. If you change the operating conditions too much from the "design point", you'll be over the max, and into self-destruct range. Personally, i wouldn't go more than about 20% over, but that's a wild guess.

 

[Mikeyworks]

Thanks for all of the comments guys. I have posted this same question now over on the Yesterday's Tractor discussion group (as recommended).

I will check out my compressor for a few things: motor speed, compressor head limits (if I can find them), availability of parts.

I have seen this same compressor head paired with higher power/speed (not sure which) motors to result in greater CFM capacity. I know there is a site out there where a guy restores and rebuilds these compressors. I will try to contact him too.

Thanks again gang.

Mikey

 

[mike944]

If you've seen the same head paired with a bigger motor, that's a perfect indicator that it can indeed handle more power.

Find out the details of that application and you have your answer. My guess is that the motor will be the same speed, but higher HP, and the pulley on the motor will be larger diameter. You can probably safely go another 10-20% over that if you want, but you're going to start shortening the life of the pump.


By the way, i googled that compressor model number. Looks like a pretty nice industrial-grade unit. Not a cheapy home improvement store special. You could probably contact the manufacturer of the pump and ask for max power/speed limits, if it's not too old.