Ken Sterling wrote in message
s.com...
Hi Offbreed,

I've wondered about this myself. I think Don's post is right on. The
only
other thing I'd add is that manufacturers, in order to save money, might
use
a motor that develops 5hp but may only have a 20% duty cycle. Make sure
the
motor/pump combo that you have is capable of running for the extended
period
of time that would be required if you upgrade your tank.


"Don Bruder" wrote in message
...
In article ,
Offbreed wrote:

I'm rebuilding an old B&S powered compressor for running some light
air tools. The motor is a 5 horse and the air tank is only about 5
gallons. Total wt, around 100 lbs.

I see posts about other compressors using 5 horse motors with much
bigger tanks. What's the deal? Did the other manufacturers just stick
a bigger tank under the compressors to provide a larger
reserve/steadier supply?


That would be the short (and pretty much correct) explanation. The
compressor itself (and what powers it) don't really care much one way
or
the other about what the capacity of the tank they're filling is. A
bigger tank (say 50 gallons, versus 5 gallons, just as a "pulled out of
thin air" example) will take longer to come up to the same pressure,
and
will take a correspondingly longer time to empty to a certain level,
certainly, but from the "viewpoint" of the power source/compressor,
they're effectively the same tank. The only significant difference is
the physical capacity of the tank, which will be directly related to
how
long it takes the motor/compressor to bring the tank up to the desired
pressure after the rig is turned on - if you don't mind waiting choose
some arbitrary amount of time for the tank to come up to pressure, the
same 5 horse motor and compressor unit that pumps up your 5 gallon tank
will handle a 50, 500, or 5000 gallon tank just as well as it does the
smaller one. The only practical "limits" on tank size are how long
you're willing to wait for the tank to hit the pressure you need for it
to be useful, how much money you're willing to spend on
buying/making/otherwise acquiring the tank, and how much physical space
you have available for it.

--
Don Bruder - - New Email policy in effect as of Feb.
21,
2004.
I respond to Email as quick as humanly possible. If you Email me and
get
no
response, see http://www.sonic.net/~dakidd/main/contact.html Short
form: I'm trashing EVERYTHING that doesn't contain a password in the
subject.



I believe the OP is talking about a Briggs & Stratton Gasoline Motor
driven air compressor - hence duty cycle not applicable....
Ken.


Hi Ken,

You could be right. When the OP used the word "motor" I assumed he was
referring to a power plant that runs off of electricity. I've always tried
to describe a gasoline driven power plant as an engine. I know that in many
cases the two words tend to get used interchangeably. I mix them up
sometimes myself. Thanks for the input.

David