X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.2 cv=aM2ykv1m c=1 sm=1 tr=0 a=cTnPuPNHK9vb6c2GqUSECg==:117 a=x7bEGLp0ZPQA:10 a=xXDCcK6TKBsA:10 a=KeKAF7QvOSUA:10 a=Ia-xEzejAAAA:8 a=Cn4YfHeJPqUPy0KWHLcA:9 a=QEXdDO2ut3YA:10 a=2xWntrdijpu45SVsLr0A:9 a=QgOlTpBtydJhr3p8:21 a=Urk15JJjZg1Xo0ryW_k8:22 From: "Todd Bartrim" Received: from mail-wm0-f45.google.com ([74.125.82.45] verified) by logan.com (CommuniGate Pro SMTP 6.2c3) with ESMTPS id 10036290 for flyrotary@lancaironline.net; Tue, 22 Aug 2017 13:48:35 -0400 Received-SPF: pass receiver=logan.com; client-ip=74.125.82.45; envelope-from=bartrim@gmail.com Received: by mail-wm0-f45.google.com with SMTP id l19so31520112wmi.1 for ; Tue, 22 Aug 2017 10:48:35 -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=0+deCbYsoR4QnbyZ383HQH8cjIqOmtIcLFNYevowsQg=; b=MeQjzhC69a3QNCMkv/UnwS+r6guChdbu3pfUHwe8PYtpDr1nM0f0goTYM9/nvRiaYy eN/iUTrp1wL+BILb9f5coB/YywwSY1SBLfJ2jNaadiaNvQS6OufwDMpMpn7fD3bS8y0O AN3sbzYx/8zkxQ5vqSrKeBQvPKnHpiYEP2/B42ZRGfj7TJ5UYG1NHPbpvxeGdmQRdBgY BsmD5aeFs0u/UVsnJCXw4uarKrZYsGUo8IwdGrVN7N/KdrKe20V9dVhmA9hYH9XHINSR pdlqPE80HDNSzHq38k6Rzhth42JYWpsYMNfPJNh5ozd6DiIcQRiyJZUsq6uyqxM4clQa E8xA== 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=0+deCbYsoR4QnbyZ383HQH8cjIqOmtIcLFNYevowsQg=; b=gQnnLJEWF4z6/S6XlZo0vRIN8miQpMh7HeiGHMgnsjls09hOfnLEOmP/kd5gAi9v7H kmhbTtv7JBcpFJyq02/EK1XjDTMc3c8F+MkGfHmc+ol31C81Pzs7jMKBQULbRTu9OTh9 u58GD4tWKzGM98zZuKZXit4obU1iOOITBIHfUr4VMgBaHyvqcKdz7yE4qD4ev2UenVHB 0vVvJN9KC2hlKzE4+I4CxhKmMzdsIC98TBvkQoTUqTlbWUarqh3PvdHruZByhzPQErOf 8jBUeOztp2S03n6hjRjnqzsf/ygyd+ggShnhQackkvUELUzGY1+y0U/7wj1rn1PFIQp0 /vyg== X-Gm-Message-State: AHYfb5jafOdiC8FaxOz2eRC7QwEG6mciSQBcHRzUZlZ1d72oHzC7q8lT KM14G/6viiafycDuK324HInwW3e68w== X-Received: by 10.80.210.215 with SMTP id q23mr759397edg.305.1503424096985; Tue, 22 Aug 2017 10:48:16 -0700 (PDT) MIME-Version: 1.0 Received: by 10.80.169.134 with HTTP; Tue, 22 Aug 2017 10:48:16 -0700 (PDT) In-Reply-To: References: Date: Tue, 22 Aug 2017 10:48:16 -0700 Message-ID: Subject: Re: [FlyRotary] Re: Heat Soak & Fuel Purge valve- Another half baked idea? To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary="f40304388c543f65e305575b339b" --f40304388c543f65e305575b339b Content-Type: text/plain; charset="UTF-8" I thought about that, but just wasn't sure it would always be enough. And the more I think about it, the more I think I'd like that ability to purge some air/vapor from the system if required. I'm quickly convincing myself that this is a good idea. But adding complexity to a fuel system unnecessarily isn't always a good idea. Todd Bartrim On Tue, Aug 22, 2017 at 7:43 AM, Ernest Christley < flyrotary@lancaironline.net> wrote: > The fuel pumps are low on the firewall, right? > > Just open the oil door when you stop. The chimney effect will be pulling > cool air over the pumps. > > > On Tuesday, August 22, 2017 2:05 AM, Todd Bartrim < > flyrotary@lancaironline.net> wrote: > > > With my improved ducting I seem to be able to withstand extensive > ground running without overheating (but, It was only 21C today), however > I've noticed that the temps really take a spike after shutdown. I measure > coolant temps out of the engine, into the Laminova exchanger, into the > engine and behind both left & right rad. What I've been seeing is the > engine temps hottest exiting the engine, cooler going back in, while > running as it should be. > But immediately after shutdown with no airflow the temps at the left > rad (closest to turbo) starts to climb. The controller for my EWP will > continue to run pump for 5 minutes after shutdown, so the coolant seems to > be absorbing this radiant heat as the temps into the Laminova and then into > the engine begin to rise as well. The engine acts like a heat sink > absorbing this heat Kinda backwards I figure. But not a big deal, if I > fire it up again or if I'm done for some time. > However when I went in for dinner and came back out an hour later I > couldn't get enough fuel pressure to start (max 16psi). I converted to a > returnless fuel system which seems great, however my hi-press fuel pumps > are firewall mounted rather than in-tank as a true returnless system has. I > do have low pressure Facet pumps supplying the system in a cool location, > however this wasn't enough to overcome the vapor pressure. I opened the > cowl oil hatch to vent the heat and an hour later I checked and all was > good again. > Previously I had a small NACA duct on the belly of the cowl feeding a 2" > scat tube to cool the fuel system in flight as I had all that other hot air > swirling around in there without proper exit ducting. That duct is still > available as I only surface filled it with foam and then glassed over it, > so I could chisel that out and use it again, but I don't think that will do > much good as it would really only cool in flight and I don't think that is > a problem. > Sorry for the long-winded preface, but here comes the half baked idea. > Instead of going back to a return type system I was thinking about a > push-button operated solenoid valve that would tee into the fuel line > before the regulator and return fuel to a main tank only while the button > is pushed. It would have to be mounted before the regulator so that it > would be able to vent hot fuel when the pumps can't reach enough pressure > to open the regulator. And because it would only open when the button is > held there would be no worries about accidentally pumping fuel overboard > through a vent from an already full tank. > So the thought is that I fly to some airport, taxi in to get that $100 > hamburger, back out an hour later, heat soak leaves me unable to get any > fuel pressure so I hold that button in for a minute while my facet pumps > move cool fuel into the system and hi-press pump starts doing it's hi-press > thing, let go of the button and start as usual. > So is this a lousy idea, a good idea, or is this already being done and > I just missed the memo? > > I welcome all comments & criticism on this. Once I haul this thing back to > the airport I really don't want to be doing any more work to it. > > > Todd Bartrim -- Half baked is what I do best! > > > --f40304388c543f65e305575b339b Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
I thought about that, but just wasn't sure it would al= ways be enough.=C2=A0
And the more I think about it, the more I think I= 'd like that ability to purge some air/vapor from the system if require= d. I'm quickly convincing myself that this is a good idea.
=C2=A0 = =C2=A0But adding complexity to a fuel system unnecessarily isn't always= a good idea.=C2=A0

Todd Bartrim

On Tue, Aug 22, 2017 at 7:43 AM, Ernest Chri= stley <flyrotary@lancaironline.net> wrote:
The fuel pumps are low on the firewall, right?

Just open t= he oil door when you stop.=C2=A0 The chimney effect will be pulling cool ai= r over the pumps.


On Tuesda= y, August 22, 2017 2:05 AM, Todd Bartrim <flyrotary@lancaironline.net> wrot= e:


=C2= =A0 =C2=A0 With my improved ducting I seem to be able to withstand extensiv= e ground running without overheating (but, It was only 21C today), however = I've noticed that the temps really take a spike after shutdown. I measu= re coolant temps out of the engine, into the Laminova exchanger, into the e= ngine and behind both left & right rad. What I've been seeing is th= e engine temps hottest exiting the engine, cooler going back in, while runn= ing as it should be.
=C2=A0 =C2=A0But immediately after shutdown with n= o airflow the temps at the left rad (closest to turbo) starts to climb. The= controller for my EWP will continue to run pump for 5 minutes after shutdo= wn, so the coolant seems to be absorbing this radiant heat as the temps int= o the Laminova and then into the engine begin to rise as well. The engine a= cts like a heat sink absorbing this heat =C2=A0Kinda backwards I figure. Bu= t not a big deal, if I fire it up again or if I'm done for some time.However when I went in for dinner and came back out an hour later I coul= dn't get enough fuel pressure to start (max 16psi). I converted to a re= turnless fuel system which seems great, however my hi-press fuel pumps are = firewall mounted rather than in-tank as a true returnless system has. I do = have low pressure Facet pumps supplying the system in a cool location, howe= ver this wasn't enough to overcome the vapor pressure. I opened the cow= l oil hatch to vent the heat and an hour later I checked and all was good a= gain.
=C2=A0 Previously I had a small NACA duct on the belly of t= he cowl feeding a 2" scat tube to cool the fuel system in flight as I = had all that other hot air swirling around in there without proper exit duc= ting. That duct is still available as I only surface filled it with foam an= d then glassed over it, so I could chisel that out and use it again, but I = don't think that will do much good as it would really only cool in flig= ht and I don't think that is a problem.
=C2=A0 =C2=A0Sorry fo= r the long-winded preface, but here comes the half baked idea.
In= stead of going back to a return type system I was thinking about a push-but= ton operated solenoid valve that would tee into the fuel line before the re= gulator and return fuel to a main tank only while the button is pushed. It = would have to be mounted before the regulator so that it would be able to v= ent hot fuel when the pumps can't reach enough pressure to open the reg= ulator. And because it would only open when the button is held there would = be no worries about accidentally pumping fuel overboard through a vent from= an already full tank.
=C2=A0 So the thought is that I fly to som= e airport, taxi in to get that $100 hamburger, back out an hour later, heat= soak leaves me unable to get any fuel pressure so I hold that button in fo= r a minute while my facet pumps move cool fuel into the system and hi-press= pump starts doing it's hi-press thing, let go of the button and start = as usual.
=C2=A0 So is this a lousy idea, a good idea, or is this= already being done and I just missed the memo?

I = welcome all comments & criticism on this. Once I haul this thing back t= o the airport I really don't want to be doing any more work to it.=C2= =A0


Todd Bartrim =C2= =A0-- =C2=A0Half baked is what I do best!


<= /div>

--f40304388c543f65e305575b339b--