Return-Path: Received: from [216.52.245.18] (HELO ispwestemail2.mdeinc.com) by logan.com (CommuniGate Pro SMTP 4.3c2) with ESMTP id 764246 for flyrotary@lancaironline.net; Tue, 01 Mar 2005 07:57:13 -0500 Received-SPF: none receiver=logan.com; client-ip=216.52.245.18; envelope-from=wschertz@ispwest.com Received: from 7n7z201 (unverified [67.136.145.243]) by ispwestemail2.mdeinc.com (Vircom SMTPRS 4.0.340.3) with SMTP id for ; Tue, 1 Mar 2005 04:56:25 -0800 Message-ID: <006201c51e5e$14135ea0$f3918843@7n7z201> From: "William" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: [FlyRotary]actual water flow was Belt rumnations; soliciting Opinions of racers please.... Date: Tue, 1 Mar 2005 06:56:19 -0600 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 Head pressure does not cancel out in a closed system. The 'head pressure' becomes the pressure rise across the pump from the intake to the exit. It is what makes the fluid flow through the rest of the system. The pump has a pump curve that starts at zero flow and max pressure rise across the pump and drops as the flow increases, and the system has a flow curve that starts at zero pressure drop at zero flow and rises as the flow increases. When the two pressure values are equal, that establishes your flow rate. Bill Schertz KIS Cruiser # 4045 ----- Original Message ----- From: "Jim Sower" > Rusty, > I only heard today that Al G. had flow data on his dyno. He might have > some ideas around this. As to head pressure, I believe I was taught that > head pressure only exists in an open system. In a closed system it all > cancels out going around the circle. > But that was a long time ago ... Jim S. > > Russell Duffy wrote: > >> What we >> need is some expire mental measurement of flow rate under actual >> conditions (which will involve a flow meter in the system) and then, >> with the engine at rest (the pump is the only moving part in the >> system), we can see how much current it takes to achieve that flow rate. >> Sadly, the pivotal instrument, a flow meter that doesn't disturb the >> system too much, is probably not available. If someone could come up >> with a flow meter in a 1.25" line, we could do some expirements. >> Other than that, we're guessing at numbers like PL and the bumblebee >> folks ... Jim S. >> >> I agree. Everyone keeps talking about all this head pressure that the >> pump is having to face. It must be stealth pressure, because my pressure >> gauge doesn't see it.