X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.2 cv=aM2ykv1m c=1 sm=1 tr=0 a=XW7ZA2AAN0ITfbjZqHzArQ==:117 a=x7bEGLp0ZPQA:10 a=KeKAF7QvOSUA:10 a=Ia-xEzejAAAA:8 a=9LjUV78RrAkDYPMLheUA:9 a=QEXdDO2ut3YA:10 a=cNRv37J1PqQ5vSjQ:21 a=_W_S_7VecoQA:10 a=Urk15JJjZg1Xo0ryW_k8:22 From: "Ernest Christley" Received: from sonic308-11.consmr.mail.gq1.yahoo.com ([98.137.68.35] verified) by logan.com (CommuniGate Pro SMTP 6.2c3) with ESMTP id 10035473 for flyrotary@lancaironline.net; Tue, 22 Aug 2017 10:43:39 -0400 Received-SPF: none receiver=logan.com; client-ip=98.137.68.35; envelope-from=echristley@att.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=att.net; s=s1024; t=1503412985; bh=ss4cd/PXIG6l52oQTNGnwUUHSOeTFD0Er/x9AwQ+hcU=; h=Date:From:Reply-To:To:In-Reply-To:References:Subject:From:Subject; b=NU5T2y59xhEJPT8UjFuMP2w72kEjGdl1kNuNWeJsWzGn2Tq7cXq7pIwtaElKRo4tNHmkYeT4x4UTOzjyS0hMkvoaRjAdlXHumODn1whQJMEJb0yca/qgTr1ttZVQzyvTBOHncesYYfXfrq7gF/FwSzC9ybcQq6xBnINm5KNGyaI= X-YMail-OSG: P_N57z0VM1nSBipcwDehhoOg5SL3g57OaI.SLviQhX0y7pyKByIr69RvGIod9.N IQ4PPIikghhKiU7mcpAZe1rCAJcCg.95yvGh1TjwA2qQL0VYaOVzk4VfvXOjsacT2T.VN4Zm2kxt O65Hn6.Op55oC3WBg1ti4MWeAfqMZPX9mfsqVe8igbCqyFkrvupsKFELUV843pGKpK9jfGuMHIXM O8eUzvGXS8XSixrKLrn1fgUvRq2B8f7BzCyoK0wtuwKo8EgKTrH62sx7vzcBXGFOid2rJqyxoNbT 7APpq0._H1W_dy3LWtDeKmpm89Zz3kTDD9yATzFMy4UJhx2HlzoZw4JcNsJgpD3xOPxe9qAvfCb1 ErGCRlSQs.vtALXF3i0WfG2R_i.s5t_11rJaijTgKzwhziphbXkjTTTm1XVHm2FLjjCs_INso3S6 rcb_ABt0OLESuZx3eTrY2Dj.vGUgkZ_XjRyBTiKsvFK3hT.c- Received: from sonic.gate.mail.ne1.yahoo.com by sonic308.consmr.mail.gq1.yahoo.com with HTTP; Tue, 22 Aug 2017 14:43:05 +0000 Date: Tue, 22 Aug 2017 14:43:04 +0000 (UTC) Reply-To: Ernest Christley To: Rotary motors in aircraft Message-ID: <683146868.448162.1503412984380@mail.yahoo.com> In-Reply-To: References: Subject: Re: [FlyRotary] Heat Soak & Fuel Purge valve- Another half baked idea? MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_448161_1021479451.1503412984378" X-Mailer: WebService/1.1-SNAPSHOT YahooMailNeo Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/603.3.8 (KHTML, like Gecko) Version/10.1.2 Safari/603.3.8 Content-Length: 8574 ------=_Part_448161_1021479451.1503412984378 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable The fuel pumps are low on the firewall, right? Just open the oil door when you stop. =C2=A0The chimney effect will be pull= ing cool air over the pumps.=20 On Tuesday, August 22, 2017 2:05 AM, Todd Bartrim wrote: =20 =C2=A0 =C2=A0 With my improved ducting I seem to be able to withstand exte= nsive ground running without overheating (but, It was only 21C today), howe= ver 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 the engine= temps hottest exiting the engine, cooler going back in, while running as i= t should be.=C2=A0 =C2=A0But immediately after shutdown with no airflow the= temps at the left rad (closest to turbo) starts to climb. The controller f= or my EWP will continue to run pump for 5 minutes after shutdown, so the co= olant seems to be absorbing this radiant heat as the temps into the Laminov= a and then into the engine begin to rise as well. The engine acts like a he= at sink absorbing this heat =C2=A0Kinda backwards I figure. But not a big d= eal, 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 p= ressure to start (max 16psi). I converted to a returnless fuel system which= seems great, however my hi-press fuel pumps are firewall mounted rather th= an in-tank as a true returnless system has. I do have low pressure Facet pu= mps 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 a= nd an hour later I checked and all was good again.=C2=A0 Previously I had a= small NACA duct on the belly of the cowl feeding a 2" scat tube to cool th= e 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 s= urface 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.=C2=A0 =C2= =A0Sorry for 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 regulat= or. And because it would only open when the button is held there would be n= o worries about accidentally pumping fuel overboard through a vent from an = already full tank.=C2=A0 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 whil= e my facet pumps move cool fuel into the system and hi-press pump starts do= ing 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 to = 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! =20 ------=_Part_448161_1021479451.1503412984378 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
The fuel pump= s are low on the firewall, right?

J= ust open the oil door when you stop.  The chimney effect will be pulli= ng cool air over the pumps.


On Tuesday, August 22, 2017 2:05 AM, To= dd 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 m= easure coolant temps out of the engine, into the Laminova exchanger, into t= he engine 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.
   But 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  Kinda backwards I figure. Bu= t not a big deal, if I fire it up again or if I'm done for some time.
H= owever 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.
<= div>  Previously I had a small NACA duct on the belly of the cowl feed= ing a 2" scat tube to cool the fuel system in flight as I had all that othe= r hot air swirling around in there without proper exit ducting. That duct i= s still available as I only surface filled it with foam and then glassed ov= er 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 val= ve that would tee into the fuel line before the regulator and return fuel t= o 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 pum= ps 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 accidenta= lly pumping fuel overboard through a vent from an already full tank.
<= div>  So the thought is that I fly to some airport, taxi in to get tha= t $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 pum= ps move cool fuel into the system and hi-press pump starts doing it's hi-pr= ess 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 mi= ssed the memo?

I welcome all comments & critic= ism 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!


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