Return-Path: Received: from [24.93.47.40] (HELO ms-smtp-01-eri0.texas.rr.com) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 2990609 for flyrotary@lancaironline.net; Fri, 13 Feb 2004 10:23:17 -0500 Received: from dell (cs6669241-190.austin.rr.com [66.69.241.190]) by ms-smtp-01-eri0.texas.rr.com (8.12.10/8.12.7) with SMTP id i1DFNDLe019824 for ; Fri, 13 Feb 2004 09:23:17 -0600 (CST) Message-ID: <002e01c3f245$52fbba40$6401a8c0@austin.rr.com> From: "Bob Darrah" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: EFI Fuel Pressure Date: Fri, 13 Feb 2004 09:23:22 -0600 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 ----- Original Message ----- From: "Scott Stout" To: "Rotary motors in aircraft" 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