X-Virus-Scanned: clean according to Sophos on Logan.com From: "Stephen Izett" Received: from mail-pd0-f173.google.com ([209.85.192.173] verified) by logan.com (CommuniGate Pro SMTP 6.0.10) with ESMTPS id 7241540 for flyrotary@lancaironline.net; Tue, 28 Oct 2014 20:02:17 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.192.173; envelope-from=steveize@gmail.com Received: by mail-pd0-f173.google.com with SMTP id v10so1762252pde.18 for ; Tue, 28 Oct 2014 17:01:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:content-type:message-id:mime-version:subject:date:references :to:in-reply-to; bh=1Dl8/XT2iOszZWwtsAo0CofXBlbzaziKwAjcB3hkaXc=; b=z9Evc9ZIDxLq3AqouO9ynbmxIXYBup/1/iFKIvB29vJw3oRQm9veMMLy5zTIqGcn8e jdNn3G47iwbqWh0IBCj+e42j0NfDRhISdnNbPOJrF9LCA0Au0ivExMji2F+59pSqKP1t Yz1f3K94BrJT3oCIzexxbOjU5ZqIc+epLrVoEC83/Jg7Q3QU0VtBf9uOhW07hBgvS8ip E0ZCumYYK3Klv0yY0SGuvAFz7oAwGIfalapTqRkkhEkFPG4TNxOIsT9y8Y8gWyYRPUGg 0TJExXR6kF4Qz6urcRRzPLxbtxhr18Rp+TCoMKKYfPAQp4d+E6DBuP+39prB0ijRPVgK UFLQ== X-Received: by 10.66.226.235 with SMTP id rv11mr6640777pac.41.1414540903392; Tue, 28 Oct 2014 17:01:43 -0700 (PDT) Return-Path: Received: from [10.1.1.12] (106-69-41-211.dyn.iinet.net.au. [106.69.41.211]) by mx.google.com with ESMTPSA id xy3sm2640520pbb.38.2014.10.28.17.01.41 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 28 Oct 2014 17:01:42 -0700 (PDT) X-Google-Original-From: Stephen Izett Content-Type: multipart/alternative; boundary="Apple-Mail=_02C7ACA1-13BA-4309-AC8C-8179968EE9C2" Message-Id: <6418F793-1764-4B36-A7D4-647F5B061B3F@icloud.com> Mime-Version: 1.0 (Mac OS X Mail 8.0 \(1990.1\)) Subject: Re: [FlyRotary] Re: electric fuel selector valves Date: Wed, 29 Oct 2014 08:01:38 +0800 References: To: Rotary motors in aircraft In-Reply-To: X-Mailer: Apple Mail (2.1990.1) --Apple-Mail=_02C7ACA1-13BA-4309-AC8C-8179968EE9C2 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Hi there Ernest. I completely agree with your logic and risk analysis. You could tow a = car with the FI hose I was using over a good barb with a quality clamp. How any well maintained vehicles have had fires associated with the = flexible lines. I believe the risk level is way below so many other = areas we don=E2=80=99t even consider. Im building a Glasair with my Father and in the end he wanted to go with = a stainless AN system. He was convinced by a race guy talking about ethanol being added to = fuels and the danger to traditional flexible lines. But we have vinyl ester tanks which won=E2=80=99t like ethanol anyway. The system we have now has many times the failure points in the form of = joints. As far as the Polak valve, I=E2=80=99m in Perth Western Australia where = are you? Ill check postage. Steve > On 29 Oct 2014, at 3:58 am, Ernest Christley = wrote: >=20 > But, WHY do you draw the line there, Mark (or anyone else that cares = to chime in)? What is the physics behind it. There are literally = MILLIONS of plastic parts running around in the fuel systems of vehicles = that live in environments much more abusive than airplanes. Fires do = happen, but for the most part they are old junkers coated in oil and = grease. =20 >=20 > And all the calls for steel braided hose: the max fuel pressure in = the project I'm working on is 6psi. There isn't a tubing manufactured = that will be noticeably stressed by 6psi. I've heard that the steel = braid is to protect the hose against abrasion. But, wouldn't a better = idea be to eliminate the rubbing, and then replace with a lighter hose = that puts less stress on expensive aluminum AN fittings that always seem = to be adapters screwed into NPT ports (ie, why not just stay with NPT if = we're using it everywhere anyhow?) And why not use a barbed fitting? = Nearly every vehicle on the highway today is using them exclusively. = Are we really expecting AN fittings to hold the rubber hoses together = when we wrap up in a ball tight enough to deform the entire airplane? >=20 > It seems we insist that the laws of physics somehow change just = because the wheels leave the ground, all in the name of doing a "little = bit better", which doesn't seem to me to translate to anything actually = beneficial. If we need a rope to hold 100lbs, and I have one rated for = 1,000lbs, is it worth paying to get a chain rated at 100,000lbs? >=20 > I'm ranting a bit, but I really can't wrap my brain around a lot of = this. I bought my current project and I've been pulling off = "improvements" the build did. I've got a fortune in AN fittings that = are totally pointless...and all to serve 4gph of fuel to an updraft = carburetor at 1.5psi. I'm just like, "SHEEESH!!" >=20 >=20 >=20 >=20 >=20 > On Tuesday, October 28, 2014 3:17 PM, Mark Steitle = wrote: >=20 >=20 > Unlike airplanes, trucks can pull over to the side of the road. = Besides, we all know that trucks/busses/RV's never catch fire. ;-0=20 > Personally, I would never use a plastic fuel valve in an airplane, but = that's just where I draw the line. YMMV.=20 > =20 > OK, I've said it. I'll go back to lurking now.=20 > =20 >=20 >=20 --Apple-Mail=_02C7ACA1-13BA-4309-AC8C-8179968EE9C2 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 Hi there Ernest.

I completely agree with your logic and risk analysis. You = could tow a car with the FI hose I was using over a good barb with a = quality clamp.
How any well maintained vehicles = have had fires associated with the flexible lines. I believe the risk = level is way below so many other areas we don=E2=80=99t even = consider.

Im building a Glasair with my Father and in the end he wanted = to go with a stainless AN system.
He was convinced = by a race guy talking about ethanol being added to fuels and the danger = to traditional flexible lines.
But we have vinyl = ester tanks which won=E2=80=99t like ethanol anyway.
The system we have now has many times the failure points in = the form of joints.

As far as the Polak valve, I=E2=80=99m in Perth Western = Australia where are you? Ill check postage.

Steve




On = 29 Oct 2014, at 3:58 am, Ernest Christley <flyrotary@lancaironline.net> wrote:

But, WHY do you draw the line there, Mark (or = anyone else that cares to chime in)?  What is the physics behind = it.  There are literally MILLIONS of plastic parts running around = in the fuel systems of vehicles that live in environments much more = abusive than airplanes.  Fires do happen, but for the most part = they are old junkers coated in oil and grease. 

And all the calls for steel braided = hose:  the max fuel pressure in the project I'm working on is = 6psi.  There isn't a tubing manufactured that will be noticeably = stressed by 6psi.  I've heard that the steel braid is to protect = the hose against abrasion.  But, wouldn't a better idea be to = eliminate the rubbing, and then replace with a lighter hose that puts = less stress on expensive aluminum AN fittings that always seem to be = adapters screwed into NPT ports (ie, why not just stay with NPT if we're = using it everywhere anyhow?)  And why not use a barbed = fitting?  Nearly every vehicle on the highway today is using them = exclusively.  Are we really expecting AN fittings to hold the = rubber hoses together when we wrap up in a ball tight enough to deform = the entire airplane?

It seems we insist that the laws of = physics somehow change just because the wheels leave the ground, all in = the name of doing a "little bit better", which doesn't seem to me to = translate to anything actually beneficial.  If we need a rope to = hold 100lbs, and I have one rated for 1,000lbs, is it worth paying to = get a chain rated at 100,000lbs?
=

I'm ranting a bit, but I really can't wrap my brain around a lot of this. I bought my current project and I've been pulling = off "improvements" the build did.  I've got a fortune in AN = fittings that are totally pointless...and all to serve 4gph of fuel to = an updraft carburetor at 1.5psi.  I'm just like, = "SHEEESH!!"





= On Tuesday, = October 28, 2014 3:17 PM, Mark Steitle <flyrotary@lancaironline.net> wrote:


Unlike airplanes, trucks can pull over to the side = of the road.  Besides, we all know that trucks/busses/RV's never = catch fire.  ;-0 
Personally, = I would never use a plastic fuel valve in an airplane, but that's just = where I draw the line.  YMMV. 
 
OK, I've said = it.  I'll go back to lurking now. 
 


=

= --Apple-Mail=_02C7ACA1-13BA-4309-AC8C-8179968EE9C2--