X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail08.syd.optusnet.com.au ([211.29.132.189] verified) by logan.com (CommuniGate Pro SMTP 5.2.2) with ESMTPS id 2874605 for flyrotary@lancaironline.net; Sun, 27 Apr 2008 18:03:01 -0400 Received-SPF: pass receiver=logan.com; client-ip=211.29.132.189; envelope-from=lendich@optusnet.com.au Received: from george (d220-237-232-70.dsl.nsw.optusnet.com.au [220.237.232.70]) by mail08.syd.optusnet.com.au (8.13.1/8.13.1) with SMTP id m3RM2C5a003999 for ; Mon, 28 Apr 2008 08:02:13 +1000 Message-ID: <003001c8a8b2$5b16e010$6400a8c0@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Electric Water pumps - Interesting Date: Mon, 28 Apr 2008 08:02:15 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002D_01C8A906.2C0433F0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 X-Antivirus: avast! (VPS 0657-0, 12/12/2006), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_002D_01C8A906.2C0433F0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Ed, The gut feeling I have on these pumps is that because they use them on = some Dyno's, their Ok for short bursts - I has assumed they would be OK = for drag racing but it seems that that is now not the case as well. I = believe your estimates as to the suitability with back pressure and = increased current requirements may be spot on. I personally couldn't recommend them to anyone for Aviation use or = continuous high end use. George ( down under) I was just thumbing through a recent catalog from Summit Racing and = came across a couple of pages on electric water pumps. There has always = been a degree of interest (and some debate {:>)) regarding the use of = electric water pumps in aircraft. It was interesting to read some of = the descriptions, but basically the current consumed ranged from 4 - 9 = amps and the quoted flow rate (presumably without back pressure) was = from 16-35 gpm. So if you take 9 amps at say 14 volts =3D 126 watts =3D 0.167 HP to = get that flow. However, some of them indicate you can save 15 - 20 = engine HP at HIGH rpm. So why the difference? Apparently (my best guess) is that they are advertising their = product to best advantage (surprise?). I would suspect that the flow = rates shown are without back pressure and that when attached to a real = engine coolant system that : 1. The flow rates would decrease=20 2. The current requirements would increase.=20 However, not to the point the electric pump would be required to make = 10HP or more to provide the required flow. I suspect there are = considerable losses (such as pump cavitation and pressure drops through = the cooling galleys)with mechanical pumps at high pump rpm as driven by = a high revving engine which accounts for the high power requirements. = Whereas the electric driven pumps may operate at lower and more = efficient rpm without the majority of those losses. That said, the pumps cost range from around $200 - $400 and while no = weights were given, basic on the photographs showing the heavy electric = motors and additional plumbing would not appear to offer any = significant weight savings over the proven, reliable mechanical pumps = most of us are using.=20 So while certainly interesting and perhaps of value in some aircraft = installations(how would you like to gain an additional 10 HP on = takeoff?), I remain confident in my old 86 13B water pump housing and = cartridge which is still going strong after 10 years. I have moved it = from my first 86 N/A engine to my current 91 turbo block, so it has = performed for over 10 years in two different engines without any = problem. Interestingly, of the 11 electrical water pumps advertised, only one = was specified for drag race use only - and it had the lowest current = drain - 3.5 amps. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.dmack.net/mazda/index.html -------------------------------------------------------------------------= ----- No virus found in this incoming message. Checked by AVG.=20 Version: 7.5.524 / Virus Database: 269.23.5/1399 - Release Date: = 26/04/2008 2:17 PM ------=_NextPart_000_002D_01C8A906.2C0433F0 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
 Ed,
The gut feeling I have on these pumps = is that=20 because they use them on some Dyno's, their Ok for short bursts - I has = assumed=20 they would be OK for drag racing but it seems that that is now not the = case as=20 well.  I believe your estimates as to the suitability with = back=20 pressure and increased current requirements may be spot on.
 
I personally couldn't recommend them to = anyone for=20 Aviation use or continuous high end use.
George ( down under)
I was just thumbing through a recent = catalog=20 from Summit Racing and came across a couple of pages on electric water = pumps.  There has always been a degree of interest (and some = debate=20 {:>)) regarding the use of electric water pumps in aircraft.  =  It=20 was interesting to read some of the descriptions, but basically the = current=20 consumed ranged from 4 - 9 amps and the quoted flow rate = (presumably=20 without back pressure) was from 16-35 gpm.
 
So if you take 9 amps at say 14 volts = =3D 126=20 watts =3D 0.167 HP to get that flow.  However, some of them = indicate you=20 can save 15 - 20 engine HP at HIGH rpm.  So why the=20 difference?
 
  Apparently (my best guess) is = that they=20 are advertising their product to best advantage (surprise?).  I = would=20 suspect that the flow rates shown are without back pressure and that = when=20 attached to a real engine coolant system that :
 
1.  The flow rates would = decrease=20
2.  The current requirements = would=20 increase. 
 
 However, not to the point the = electric=20 pump would be required to make 10HP or more to provide the required=20 flow.  I suspect there are considerable losses (such as pump = cavitation=20 and pressure drops through the cooling galleys)with mechanical pumps =  at=20 high pump rpm as driven by a high revving engine which accounts for = the high=20 power requirements.  Whereas the electric driven pumps may = operate at=20 lower and more efficient rpm without the majority of those=20 losses.
 
That said, the pumps cost range from = around=20 $200 - $400 and while no weights were given, basic on the=20 photographs showing the heavy electric motors and additional plumbing=20  would not appear to offer any significant weight savings over = the=20 proven, reliable mechanical pumps most of us are = using. 
 
 So while certainly interesting = and=20 perhaps of value in some aircraft installations(how would you like to = gain an=20 additional 10 HP on takeoff?), I remain confident in my old 86 13B = water pump=20 housing and cartridge which is still going strong after 10 = years.  I have=20 moved it from my first 86 N/A engine to my current 91 turbo block, so = it has=20 performed for over 10 years in two different engines without any=20 problem.
 
Interestingly, of  the  11 = electrical=20 water pumps advertised, only one was specified for drag race use only = - and it=20 had the lowest current drain - 3.5 amps.
 
Ed
 
Ed Anderson
Rv-6A N494BW Rotary=20 Powered
Matthews, NC
eanderson@carolina.rr.comhttp://www.andersonee.com
http:/= /members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.dmack.net/mazda= /index.html

No virus found in this incoming message.
Checked by AVG.=20
Version: 7.5.524 / Virus Database: 269.23.5/1399 - Release Date:=20 26/04/2008 2:17 PM
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