X-Virus-Scanned: clean according to Sophos on Logan.com From: "steve Izett" Received: from mail-pg0-f46.google.com ([74.125.83.46] verified) by logan.com (CommuniGate Pro SMTP 6.2c1) with ESMTPS id 9606721 for flyrotary@lancaironline.net; Fri, 24 Mar 2017 19:35:01 -0400 Received-SPF: pass receiver=logan.com; client-ip=74.125.83.46; envelope-from=steveize@gmail.com Received: by mail-pg0-f46.google.com with SMTP id t143so2178541pgb.2 for ; Fri, 24 Mar 2017 16:35:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:mime-version:subject:date:references:to:in-reply-to:message-id; bh=kvQ0JTJV5homEkG3K3dlUXkVaJEntWNGn44JuuvyUQw=; b=DW9ygaBKXaKDaLZXzjY2xkJYjvgvScX5+74+MueSrY+UT+awbahhJ7pCGIZCbAoqiS tVv6si1Y3c/IVmxhCtE+mRKbHdYX4lN7M1IbhUn61rCXlSy0gWdyC3cnF66ACHIzSnLZ kYMpwtqaV4zBBHLsl6tvnhWhU1aGy1PO40U3UJnl5URV8gZYdTerxpkYafjRWGk2JMQ/ ewKG5buLXkWeIoIBK69LC6kHp3Zyj/6O+GXx+zIEfI3S7tZNXC8z1UT9jQchVtiUn81Q 2PTTdu9rnJsY75pbWiLDgk+omNCHU1XHfXlZiYIsLFssps+OFvf6LVM47FT6UAoMwhxd djAA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:mime-version:subject:date:references:to :in-reply-to:message-id; bh=kvQ0JTJV5homEkG3K3dlUXkVaJEntWNGn44JuuvyUQw=; b=WoiX2lKHiH3g6MsAoNu8xPN8gQ9ZRbqA1UHWM6LolyDPS8qniMLgRnHshnmV9F5fjP bOemj0mN/7yETbgZ2LqeKtOTjL2kppABeTo3SvjNvv80Z1PJamNcbIZoyYlS82ZfI0+L 5p6yJ+bW5APAleEuratm+/oY9JBBFXHQfqt/qSLloPcc3K161FT05mJGOHRiedx+drHu pe5rm9sLoPoY+8flUeSq2+jLWM8KXmgwsiIYbymWD1c/dLOG0td5/9a3f3SwH2Rw+n95 zGE+6WigpfQkBUvitb8Wm87HvBAxzvNLwUJS5s5gGPegeEjoTE+kzyjwun/cXCdRJALg 4+sQ== X-Gm-Message-State: AFeK/H22sk8/86nfyReK2V4muCVCq83S0FP++m3I+GbxguuRGhXuB9rUm7Kgw8QgJNm87w== X-Received: by 10.98.214.4 with SMTP id r4mr11916957pfg.185.1490398485532; Fri, 24 Mar 2017 16:34:45 -0700 (PDT) Return-Path: Received: from [10.1.1.6] ([124.169.71.123]) by smtp.gmail.com with ESMTPSA id g27sm6646649pfk.95.2017.03.24.16.34.42 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 24 Mar 2017 16:34:44 -0700 (PDT) Content-Type: multipart/alternative; boundary="Apple-Mail=_71E3F622-1046-4ECA-90DB-E4C5D4D44274" Mime-Version: 1.0 (Mac OS X Mail 10.2 \(3259\)) Subject: Re: [FlyRotary] Re: Fuel Pump current and pressures Date: Sat, 25 Mar 2017 07:34:40 +0800 References: To: Rotary motors in aircraft In-Reply-To: Message-Id: <620169D6-B1EB-453F-9A80-8B21D4A52AE2@gmail.com> X-Mailer: Apple Mail (2.3259) --Apple-Mail=_71E3F622-1046-4ECA-90DB-E4C5D4D44274 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Yes Charlie Higher current for less pressure developed which I presume mean less = flow! Steve > On 25 Mar 2017, at 2:24 am, Charlie England = wrote: >=20 > Hey Steve,=20 >=20 > Just re-read your post with the measurements, & I'm not sure which had = higher current draw. It was the bottom pump, right? >=20 > Thanks, >=20 > Charlie >=20 > On 3/24/2017 8:06 AM, Stephen Izett wrote: >> Good idea Charlie.=20 >> That would clear it up as far as the manifold flow characteristics. >> Just a pain in the but to get to. >> Thanks >> Steve >>=20 >>=20 >>=20 >>> On 24 Mar 2017, at 8:56 pm, Charlie England = > = wrote: >>>=20 >>> Have you tried swapping the position of the pumps & making the same = measurements? It's hard to imagine it making that much difference, but = the bottom pump does have a tight right turn and then a sharp edged 'T' = turn to the left. I couldn't guess how much, but that = would account for at least some pressure increase.=20 >>>=20 >>> Charlie >>>=20 >>> On Fri, Mar 24, 2017 at 4:14 AM, steve Izett = > = wrote: >>> Hi Guys >>> Hi Peoples >>>=20 >>> Here is a photo of our parallel pumps plumbed with 3/8 aluminium = lines feed from a 28 gallon header tank above to the right. >>> Fuel then passes through the firewall and race filter before feeding = the rail and returning via the pressure regulator (4cyl toyota reg)=20 >>> back through the firewall to the header tank, again in 3/8. >>>=20 >>> I did further measurements today.=20 >>>=20 >>> 1. Bottom Pump only ~8A and 48psi - Turning both pumps on this pump = draws 9.9A and produces a rail pressure of 65psi >>> 2. Bottom Pump only ~9.9A and 44psi - Turning both pumps on this = pump draws 14.8A and produces the same rail pressure of 65psi >>>=20 >>> So bottom pump goes from 8.0 -> 9.9A (1.9A increase) under higher = head pressure >>> Top pump goes from 9.9A -> 14.8A (5.1A increase) under same head!! >>>=20 >>> Clearly Pressure Reg bypass capacity is inadequate for both pumps, = perhaps with even one pump running.=20 >>> (I don=E2=80=99t have data of fuel pressure under load to see if it = drops as power is applied) >>> I think I modelled the pump layout/manifold after seeing someone = else=E2=80=99s and not sure if it causes any problems? >>> The pumps came from eBay stating that they were genuine Walbro and = now I=E2=80=99m wondering. >>>=20 >>> Cheers >>>=20 >>> Steve Izett >>> Glasair Super II RG Renesis 4 port RD1C EC3 EM3=20 >>>=20 >>>=20 >>>=20 >>>=20 >>>=20 >>> >>>=20 >>=20 >=20 --Apple-Mail=_71E3F622-1046-4ECA-90DB-E4C5D4D44274 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 Yes Charlie
Higher current for less pressure = developed which I presume mean less flow!

Steve

On = 25 Mar 2017, at 2:24 am, Charlie England <flyrotary@lancaironline.net> wrote:

=20 =20
Hey Steve,

Just re-read your post with the measurements, & I'm not sure which had higher current draw. It was the bottom pump, right?

Thanks,

Charlie

On 3/24/2017 8:06 AM, Stephen Izett wrote:
Good idea Charlie. 
That would clear it up as far as the manifold flow characteristics.
Just a pain in the but to get to.
Thanks
Steve



On 24 Mar 2017, at 8:56 pm, Charlie = England <flyrotary@lancaironline.net> wrote:

Have you tried swapping the position of the pumps & making the same measurements? It's hard to imagine it making that much difference, but the bottom pump does have a tight right turn and then a sharp edged 'T' turn to the left. I couldn't guess how much, but that would account for at least some pressure increase. 

Charlie

On Fri, Mar 24, 2017 at = 4:14 AM, steve Izett <flyrotary@lancaironline.net> wrote:
Hi = Guys
Hi Peoples

Here is a photo of our parallel pumps plumbed with 3/8 aluminium lines feed from a 28 gallon header tank above to the right.
Fuel then passes through the firewall and race filter before feeding the rail and returning via the pressure regulator (4cyl toyota reg) 
back through the firewall to the header tank, again in 3/8.

I did further measurements = today. 

1. Bottom Pump only ~8A and = 48psi - Turning both pumps on this pump draws 9.9A and produces a rail pressure of 65psi
2. Bottom Pump only ~9.9A = and 44psi - Turning both pumps on this pump draws 14.8A and produces the same rail pressure of 65psi

So bottom pump goes from 8.0 = -> 9.9A (1.9A increase) under higher head pressure
Top pump goes from 9.9A -> 14.8A (5.1A increase) under same head!!

Clearly Pressure Reg bypass capacity is inadequate for both pumps, perhaps with even one pump running. 
(I don=E2=80=99t have data of = fuel pressure under load to see if it drops as power is applied)
I think I modelled the pump layout/manifold after seeing someone else=E2=80=99= s and not sure if it causes any problems?
The pumps came from eBay stating that they were genuine Walbro and now I=E2=80=99= m wondering.

Cheers

Steve Izett
Glasair Super II RG Renesis 4 = port RD1C EC3 EM3 





<Fuel Pres Pumps.JPG>




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