----- Original Message -----
From: "Scott Stout" <squiggles@yahoo.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Friday, February 13, 2004 7:03 AM
Subject: [FlyRotary] Re: EFI Fuel Pressure


>
>
> Now venturing down the pressure path...I am confused...How can the
> weight/volume of the fuel above the measuring point be ignored?

Easy, only the height matters.
>
>
> So,  I have a 1 gallon 12 inch square bucket filled with 1 gallon of
> fuel, it weighs 6 pounds today.  If I raise this bucket 25 inches above
> the ground, attach a 25" vertical tube to the bottom of the bucket and
> measure the pressure I will have 1 psi of pressure?

Top of the fluid to the bottom of the tube, about  1 psi.  Doesn't matter if
it's a 3/8" line. a 3" line or a 3 foot line.
>
>
> Now I change the amount of fuel I want to have 25 inches off the ground
> to 2 gallons.  However, I also change the square bucket to be big enough
> to hold the 2 gallons so that the fuel level is the same as the original
> 1 gallon bucket.  Thus, the height of the fuel in the bucket is the same
> whether it is 1 gallon or 2 gallons.  Does the pressure at the bottom of
> the 25 inch tube measure something other than 1psi?  2psi?  1.5psi?

Nope, still 1 psi
>
>
> Yep...Definitely time for that 2nd cup of coffee...

Are you sure you don't want to make that a beer?
>
>
> Thanx for the help...
>
> -Scott

Sounds like it was more confusion than help.  But this is one instance where
Mother Nature made it easy for us.  Only height matters, volum dosen't.

Bob Darrah