X-Virus-Scanned: clean according to Sophos on Logan.com From: "Andrew Martin" Received: from mail-wi0-f172.google.com ([209.85.212.172] verified) by logan.com (CommuniGate Pro SMTP 6.0.10) with ESMTPS id 7241396 for flyrotary@lancaironline.net; Tue, 28 Oct 2014 18:24:30 -0400 Received-SPF: none receiver=logan.com; client-ip=209.85.212.172; envelope-from=andrew@martinag.com.au Received: by mail-wi0-f172.google.com with SMTP id bs8so174455wib.11 for ; Tue, 28 Oct 2014 15:23:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type; bh=8Az7lBb3I1NxHP6xsFMf845Ps2LFIbsgPKpDUZJGDrg=; b=AjIkSimqyCi9Z/1HPo3/WOTGiAj9W4KA2v7uhpplcPawCInThZshPlrsFI+SF6QrNL No45hqRZJ+fnfo1PMVI+jA9FHOKMWKXAoioBMSh2R9InRSDmxBeJqTaWNjPir+ge2VxZ SBsYir2wkqn0Rf3+r4bsSDh1/B7RW97RU1YJp7NiNV5No/LlExCsqoQh3pCUf19djaUC yIqNI11blxWpWC2PS9eVEQ77q5/vUeiHczMD8YUB+9FIKFrxO1ecIxNMYW1IlngU9AUo Uyaw8vpwJxu5HUsEzEY+K5y9b5hg4sX+bGbaHyYskrYbbZjHEE6deLBf9oht17+/tQD+ F57Q== X-Gm-Message-State: ALoCoQkpYhv2VFrKmvG52fE0GFnnBmK57gras9KXukphiU3EReANeus4O/bj2dQiQX85lNR9piBa MIME-Version: 1.0 X-Received: by 10.180.7.233 with SMTP id m9mr31892239wia.39.1414535036053; Tue, 28 Oct 2014 15:23:56 -0700 (PDT) Received: by 10.27.217.19 with HTTP; Tue, 28 Oct 2014 15:23:55 -0700 (PDT) X-Originating-IP: [202.40.0.40] In-Reply-To: References: Date: Wed, 29 Oct 2014 06:23:55 +0800 Message-ID: Subject: Re: [FlyRotary] Re: electric fuel selector valves To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=f46d044287ba58be5b0506831a9e --f46d044287ba58be5b0506831a9e Content-Type: text/plain; charset=UTF-8 Earnest, I think you'll find the reason behind braided fuel lines is that they also act as a handy earth strap, probably wont carry starter loads so may give a surprise, but the plane is usually on the ground at that time. Andrew On Wed, Oct 29, 2014 at 4:00 AM, Ernest Christley < flyrotary@lancaironline.net> wrote: > I'm not saying you're wrong, Mark. I do hope that part was clear. > > > > > On Tuesday, October 28, 2014 3:58 PM, 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. > > > > > > --f46d044287ba58be5b0506831a9e Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Earnest, I think you'll find the reason behind braided= fuel lines is that they also act as a handy earth strap, probably wont car= ry starter loads so may give a surprise, but the plane is usually on the gr= ound at that time.

And= rew



On Wed, Oct 29, 2014 at 4:00 AM, Ernest Chri= stley <flyrotary@lancaironline.net> wrote:
I'm not saying you're wrong, = Mark.=C2=A0 I do hope that part was clear.




=
On Tuesday, October 28, 2014 3:58= PM, Ernest Christley <flyrotary@lancaironline.net> wrote:

But, WHY do you draw the line there, Mark= (or anyone else that cares to chime in)?=C2=A0 What is the physics behind = it.=C2=A0 There are literally MILLIONS of plastic parts running around in t= he fuel systems of vehicles that live in environments much more abusive tha= n airplanes.=C2=A0 Fires do happen, but for the most part they are old junk= ers coated in oil and grease.=C2=A0

And all the call= s for steel braided hose:=C2=A0 the max fuel pressure in the project I'= m working on is 6psi.=C2=A0 There isn't a tubing manufactured that will= be noticeably stressed by 6psi.=C2=A0 I've heard that the steel braid = is to protect the hose against abrasion.=C2=A0 But, wouldn't a better i= dea 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 a= dapters screwed into NPT ports (ie, why not just stay with NPT if we're using it everywhere anyhow?)=C2=A0= And why not use a barbed fitting?=C2=A0 Nearly every vehicle on the highwa= y today is using them exclusively.=C2=A0 Are we really expecting AN fitting= s 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 th= e laws of physics somehow change just because the wheels leave the ground, all in the name of doing a "little bit better", which do= esn't seem to me to translate to anything actually beneficial.=C2=A0 If= we need a rope to hold 100lbs, and I have one rated for 1,000lbs, is it wo= rth 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 pullin= g off "improvements" the build did.=C2=A0 I've got a fortune = in AN fittings that are totally pointless...and all to serve 4gph of fuel t= o an updraft carburetor at 1.5psi.=C2=A0 I'm just like, "SH= EEESH!!"





On Tuesday, October 28, 2= 014 3:17 PM, Mark Steitle <flyrotary@lancaironline.net> wrote:
 =


Unlike airplanes, trucks c= an pull over to the side of the road.=C2=A0 Besides, we all know that truck= s/busses/RV's never catch fire.=C2=A0 ;-0=C2=A0
Personally, I= would never use a plastic fuel valve in an airplane, but that's just w= here I draw the line.=C2=A0 YMMV.=C2=A0
=C2=A0
OK, I&#= 39;ve said it.=C2=A0 I'll go back to lurking now.=C2=A0
=C2= =A0





--f46d044287ba58be5b0506831a9e--