X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imo-d04.mx.aol.com ([205.188.157.36] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2384804 for flyrotary@lancaironline.net; Sat, 13 Oct 2007 08:07:49 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.157.36; envelope-from=Lehanover@aol.com Received: from Lehanover@aol.com by imo-d04.mx.aol.com (mail_out_v38_r9.3.) id q.c6d.19c3c9ee (65100) for ; Sat, 13 Oct 2007 08:07:06 -0400 (EDT) From: Lehanover@aol.com Message-ID: Date: Sat, 13 Oct 2007 08:07:06 EDT Subject: Re: [FlyRotary] Re: FW: [FlyRotary] Re: Coolant Water Pressure To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1192277226" X-Mailer: 9.0 Security Edition for Windows sub 5378 X-Spam-Flag: NO -------------------------------1192277226 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 10/12/2007 5:50:23 P.M. Eastern Daylight Time, alwick@juno.com writes: That's quite the surprise. Japanese engineers are expert at making sure the design has extra safety margin. Even back in the 70's. Although they are much better at it now. I can't imagine they are rpm sensitive 33 years later. I have heard of a lot of guys adding flow restrictions on pump inlet, not aware they are increasing pressure drop. Particularly true with fuel systems. -al wick My pump outlet has a 5/8" hole restrictor on the outlet. Same two water pumps for 9 years. Shifting at 9,600 RPM. No cavitation damage at all. Generally the radiator(s) will be enough restriction to keep the pump well below its top flow rate, and lowest inlet pressure. If there is little or no restriction on the outlet side, the pump might cavitate momentarily during acceleration. More likely with lower total system pressure, and low restriction. Less likely with an accumulator system and more restriction,and higher system pressure. Less likely with low system volume. More likely with high system volume. With just a bit of anti freeze and its anti foaming agents, very unlikely. More likely when air remains in the system. The pumps are mounted high on the block, and will not pump at all with a bit of air sitting in them. It is critical that the pump be submerged prior to start up. Lynn E. Hanover ************************************** See what's new at http://www.aol.com -------------------------------1192277226 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 10/12/2007 5:50:23 P.M. Eastern Daylight Time,=20 alwick@juno.com writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
That's quite the surprise. Japanese engin= eers are=20 expert at making sure the design has extra safety margin. Even back in the= =20 70's. Although they are much better at it now. I can't imagine they are rp= m=20 sensitive 33 years later.
 
I have heard of a lot of guys adding flow= =20 restrictions on pump inlet, not aware they are increasing pressure drop.=20 Particularly true with fuel systems.
 
-al wick
=
My pump outlet has a 5/8" hole restrictor on the outlet. Same two water= =20 pumps for 9 years. Shifting at 9,600 RPM. No cavitation damage at all. Gener= ally=20 the radiator(s) will be enough restriction to keep the pump well below its t= op=20 flow rate, and lowest inlet pressure. If there is little or no restriction o= n=20 the outlet side, the pump might cavitate momentarily during acceleratio= n.=20
 
More likely with lower total system pressure, and low restriction. Less= =20 likely with an accumulator system and more restriction,and higher system=20 pressure. Less likely with low system volume. More likely with high sys= tem=20 volume. With just a bit of anti freeze and its anti foaming agents, very=20 unlikely. More likely when air remains in the system. The pumps are mounted=20= high=20 on the block, and will not pump at all with a bit of air sitting in them. It= is=20 critical that the pump be submerged prior to start up.
 
Lynn E. Hanover



See w= hat's new at AOL.c= om and Make AOL Your Homepage.
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