X-Virus-Scanned: clean according to Sophos on Logan.com From: "Charlie England" Received: from mail-pg0-f43.google.com ([74.125.83.43] verified) by logan.com (CommuniGate Pro SMTP 6.2c1) with ESMTPS id 9579143 for flyrotary@lancaironline.net; Fri, 17 Mar 2017 08:40:35 -0400 Received-SPF: pass receiver=logan.com; client-ip=74.125.83.43; envelope-from=ceengland7@gmail.com Received: by mail-pg0-f43.google.com with SMTP id b129so40660379pgc.2 for ; Fri, 17 Mar 2017 05:40:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=e6aBrrtouoSa8mHJfW/MJTL8YVaoVP3yeo9dPhomC0A=; b=BWr2RHzJbiRnVPM7EzBXYIeTVt+n5vNOl7eGmJFRlvh8Lemrhodo060f5r/WGXIjUq juWH3tk8IxNTgTOfPYWw3plzD7/ANIouSxgP5hC91/kyIuF1LcvayRcgjR9AogDawk78 ksSPISHc0RIDonBsuCpaeK+usSPlCvCIkWZstTsHNSar7rh0Pvf2nkoSNT5AFFSIs+I/ 70WnlWuLwBdf7AaCB/IRR0d3f9wcDbSNeUF4xy76wrFwZrl+OncL74GEnpRP/k4F4sl9 4j7kdtQA78OCkkBmpquhLXvgJ3ZQfdbXN6kGYG4PO03hsaIY+4+E9Fq9dXu9S9hrHSln qXEw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=e6aBrrtouoSa8mHJfW/MJTL8YVaoVP3yeo9dPhomC0A=; b=AaXsX59uIKd/QvQhqPTj+hFt9auE4DgxJPRWHDEjhGceUEAIImo0+mG3Ab7Lh3GqFj 0Abq2GLXeQiehWzakw61P/OauARkeHajT7KwOSjfa9jLnWyWrA/jGkUDutpnpGGtqgpJ x6F+ewceTN/ANlnsJWlYMVpDDUUK9h8puVH+h6J0lq+dtBvOPoibft+2kb2pvVtrHrc/ GjYsJdtCDswJAAD37MLnrQZdt9Vfbc7LSluWr122as6IBqwwYT5AJgGQWfWKa6p/cthh 7qwwyvhMtl58Nkz1GNKmescen+5j2xPnxIoF5Q4i0wb2onZEFr7wp+yVigbZyYrb6351 VCWg== X-Gm-Message-State: AFeK/H1ctfiwdUqj6XSzIvWHazVrIfx8UBh7yX/lQtUDDm8tKeZR7HloT2D/YYRjZM1r60o2wmDR+JyWlyRCDA== X-Received: by 10.84.232.134 with SMTP id i6mr20058917plk.101.1489754416542; Fri, 17 Mar 2017 05:40:16 -0700 (PDT) MIME-Version: 1.0 Received: by 10.100.128.83 with HTTP; Fri, 17 Mar 2017 05:40:16 -0700 (PDT) In-Reply-To: References: Date: Fri, 17 Mar 2017 07:40:16 -0500 Message-ID: Subject: Re: [FlyRotary] Re: Fuel Pump and Regulator To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=f40304361e34cd04ef054aec7a55 --f40304361e34cd04ef054aec7a55 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable As Andrew says, my Walbro GSL393 pumps (from Tracy, before he retired) say '20 Amp Fuse' right on the pump. If you don't already know this, an automotive blade fuse is a relatively fast blow device; it will blow at the slightest provocation. 'Aircraft quality' circuit breakers, on the other hand, are basically 'extremely slow blow' devices. They can take seconds to trip, unless the overload is extreme. The nature of blade fuses is probably why Walbro specs 20 amp fuses; the load on the positive displacement pump is going to be changing constantly with injectors opening/closing, fuel lines expanding/contracting, mechanical regulator opening/closing, etc. If you're using a different pump, the equation might change. I've got some little in-tank turbine pumps I'm playing with that only draw about 6 amps at full load. BTW, there's a recent thread on the VAF forum about electrical architecture surrounding the new (to Lyc drivers) automotive style injection, where one of the really smart contributors, who's done both Lyc and alt engine installs, makes the case that 'switchology' would be safer it it's as close as possible to conventional a/c techniques. He advocates that the primary pump have protection, but come up with the engine controller automatically, and only the backup pump get a separate switch. (Different subject; may start a new thread...) Charlie "Steve, I have two pumps in parallel - one pump usually indicates 35-36psi, when the second pump is on about 40 psi. Both umps use 10 amp switched breakers. Jeff" On Fri, Mar 17, 2017 at 6:05 AM, Andrew Martin wrote: > Hi Steve > Pretty sure the pumps have 20 amp fuse required stamped on them. they can > draw about 8-9 amp so 10 was just too close. you don't want to be changin= g > these in flight. > stick with the regulator you got. in practice you wont be using both pump= s > unless one fails so the 10 psi increase wont happen in flight. the > regulator has to flow the most when the engine is stopped but pump on. I'= d > doubt you'd see same increase at full rpm. A bigger regulator may not be = a > total fix it either, would need large fuel lines also to flow 2 pumps wor= th > of fuel. > I think just a switch on the panel is fine for activating the pumps, a > pressure switch is just something else to fail. and you may not realise > you've got a bad pump. it would have to be setup to switch pumps and send > you an alert, all of which can be done manually without much stress. > cheers > Andrew > > > > On Fri, Mar 17, 2017 at 5:44 PM, steve Izett > wrote: > >> Hi Guys >> >> I fired up my secondary fuel pump for the first time today and was met >> with what I didn=E2=80=99t expect. >> Instead of seeing a blip in the fuel pressure, I had a 10psi increase an= d >> high current draw from the pump which blew its 10amp fuse. >> I=E2=80=99ll up the fuse as its too low me thinks. >> >> I used an old fuel regulator I had on a rail. It was of a Toyota 4AGE >> engine of about 135hp. >> Seems like its not able to bypass enough fuel with both pumps running. >> >> I think I need to install a higher power adjustable regulator. >> What experience do you guys have with turning both pumps on >> simultaneously? >> >> I=E2=80=99m putting a pressure switch in the circuit to turn on the back= up pump >> if the fuel pressure drops below a preset level. >> >> Appreciate your thoughts and experience. >> >> Steve Izett >> Genesis 4 port EC3 EM3 RD1C in a Glasair Super II RG still nearly >> finished! >> -- >> Homepage: http://www.flyrotary.com/ >> Archive and UnSub: http://mail.lancaironline. >> net:81/lists/flyrotary/List.html >> > > --f40304361e34cd04ef054aec7a55 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable

As An= drew says, my Walbro GSL393 pumps (from Tracy, before he retired) say '= 20 Amp Fuse' right on the pump. If you don't already know this, an = automotive blade fuse is a relatively fast blow device; it will blow at the= slightest provocation. 'Aircraft quality' circuit breakers, on the= other hand, are basically 'extremely slow blow' devices. They can = take seconds to trip, unless the overload is extreme.

The nature of blade fuses is probably wh= y Walbro specs 20 amp fuses; the load on the positive displacement pump is = going to be changing constantly with injectors opening/closing, fuel lines = expanding/contracting, mechanical regulator opening/closing, etc.

If you're using a differ= ent pump, the equation might change. I've got some little in-tank turbi= ne pumps I'm playing with that only draw about 6 amps at full load. BTW= , there's a recent thread on the VAF forum about electrical architectur= e surrounding the new (to Lyc drivers) automotive style injection, where on= e of the really smart contributors, who's done both Lyc and alt engine = installs, makes the case that 'switchology' would be safer it it= 9;s as close as possible to conventional a/c techniques. He advocates that = the primary pump have protection, but come up with the engine controller au= tomatically, and only the backup pump get a separate switch. (Different sub= ject; may start a new thread...)

Charlie


"Steve= , I have two pumps in parallel - one pump usually indicates 35-36psi, when = the second pump is on about 40 psi.

Both umps use 10 amp switched breakers.

Jeff"= ;


On Fri, Mar = 17, 2017 at 6:05 AM, Andrew Martin <flyrotary@lancaironline.net<= /a>> wrote:
=
Hi Steve
Pretty sure the pumps hav= e 20 amp fuse required stamped on them. they can draw about 8-9 amp so 10 w= as just too close. you don't want to be changing these in flight.
stick with the regulator you got. in practice you wont be using both pu= mps unless one fails so the 10 psi increase wont happen in flight. the regu= lator has to flow the most when the engine is stopped but pump on. I'd = doubt you'd see same increase at full rpm. A bigger regulator may not b= e a total fix it either, would need large fuel lines also to flow 2 pumps w= orth of fuel.
I think just a switch on the panel is fine for activ= ating the pumps, a pressure switch is just something else to fail. and you = may not realise you've got a bad pump. it would have to be setup to swi= tch pumps and send you an alert, all of which can be done manually without = much stress.
cheers
Andrew



On Fri, Mar 17, 2017 at 5:44 PM, steve Izett= <flyrotary@lancaironline.net> wrote:
Hi Guys

I fired up my secondary fuel pump for=C2=A0 the first time today and was me= t with what I didn=E2=80=99t expect.
Instead of seeing a blip in the fuel pressure, I had a 10psi increase and h= igh current draw from the pump which blew its 10amp fuse.
I=E2=80=99ll up the fuse as its too low me thinks.

I used an old fuel regulator I had on a rail. It was of a Toyota 4AGE engin= e of about 135hp.
Seems like its not able to bypass enough fuel with both pumps running.

I think I need to install a higher power adjustable regulator.
What experience do you guys have with turning both pumps on simultaneously?=

I=E2=80=99m putting a pressure switch in the circuit to turn on the backup = pump if the fuel pressure drops below a preset level.

Appreciate your thoughts and experience.
Steve Izett
Genesis 4 port EC3 EM3 RD1C in a Glasair Super II RG still nearly finished!=
--
Homepage:=C2=A0 http://www.flyrotary.com/
Archive and UnSub:=C2=A0 =C2=A0http://mail= .lancaironline.net:81/lists/flyrotary/List.html


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