OBA calculations.. - Off-Road Forums & Discussion Groups
Jeep-Short Wheelbase All discussion of short wheelbase Jeeps: CJ, TJ, YJ and JK

LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 04-10-2002, 09:02 PM Thread Starter
Join Date: May 2001
Posts: 3,501
Thanks: 0
Thanked 0 Times in 0 Posts
OBA calculations..

I know it was on here earlier, but this is a little different.

Any math wizzes in here calculated how long it takes a York to fill from empty to 150PSI on different sized tanks..

I was thinking instead of getting a huge compressor for painting, sandblasting, and or tools, why not just have a cheap 50 gallon tank in the garage with no compressor and plug your jeep into it when you need go-juice?

I was just wondering about the fill rate on a big tank like that.. would it be 5 min? or 50 min?
Infernozx is offline  
Sponsored Links
post #2 of (permalink) Old 04-11-2002, 08:01 AM
Jim_Lou's Avatar
Join Date: Dec 2001
Location: Belleville, Illinois
Posts: 11,502
Thanks: 15
Thanked 22 Times in 17 Posts
Re: OBA calculations..

Compressors are rated in SCFM at some output pressure. SCFM stands for standard cubic feet per minute. "Standard" means normal atmospheric pressure and temperature - it's really defining how much air the pump will take in.

With your 50 gallon tank, every time you put another 50 gallons of air into it, the pressure will go up by about 15 PSI. To get your tank from atmospheric pressure to 150 PSI you will have to put in 10 times 50 gallons. There are about 6.4 gallons per cubic foot, so your compressor will need to pump 10 X 50 / 6.4, or about 78 cubic feet. With a 1.2 SCFM compressor you're looking at 65 minutes.

Now, there are two more factors to consider. First is that single stage compressors usually get pretty inefficient above about 125 PSI, so you will typically see them rated so many SCFM at 90 PSI or 100 PSI. In that case, they might only pump half their rating at 125, and might never make 150.

Second, if you're using an AC compressor, it's not designed to pump air to continuously higher pressures, and doesn't have the cooling fins that air compressors do. As it gets hot it will loose efficiency and pump less.
Jim_Lou is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Off-Road Forums & Discussion Groups forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome