X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from nm28-vm0.bullet.mail.sp2.yahoo.com ([98.139.91.234] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with SMTP id 5091151 for flyrotary@lancaironline.net; Sat, 13 Aug 2011 14:52:20 -0400 Received-SPF: none receiver=logan.com; client-ip=98.139.91.234; envelope-from=roundrocktom@yahoo.com Received: from [98.139.91.67] by nm28.bullet.mail.sp2.yahoo.com with NNFMP; 13 Aug 2011 18:51:45 -0000 Received: from [98.139.91.26] by tm7.bullet.mail.sp2.yahoo.com with NNFMP; 13 Aug 2011 18:51:45 -0000 Received: from [127.0.0.1] by omp1026.mail.sp2.yahoo.com with NNFMP; 13 Aug 2011 18:51:45 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 491880.55931.bm@omp1026.mail.sp2.yahoo.com Received: (qmail 47949 invoked by uid 60001); 13 Aug 2011 18:51:44 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1313261503; bh=yZS4S8fyABqYTvaAePQb/pL1o6+iBj4HAY/FYyL4Toc=; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=VWJ6DF50whjH8gnXye65WSanM/hKn79fRvaxPNzhh0h1oU6lO41ARu8Bv4KotK3erE6416Pz0ZhwqVgOEzdVNwv7tFv7dJG0HAiYoY1+mna97VvkdeEtAhD27+1MI+os/A7Qozwimb3l9Vr/12Rc0y5SvjpUe0mdn0wYNUv2Hi4= DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=Nt8JCg50efrY/XWXbUxy+BRE2wUIydqkPwlN60DjNwamHhpHi/304mav5tLraeB2ftKeOgguvpmZ9w4/LIwLbWLKVEW2A/lSv3YBiOvZZU+2tB/3rYE3XueDD+5ACDXs3DoEPSSZJscjwCF50IUJSzesz5K7Srykt19901UW65k=; X-YMail-OSG: oLQgakAVM1nGt_.da4ZFaVsHmP3J3ehPyYk_IHwfNsWZVh9 aRX3qVCD55C8kRGKmYcNbdQVsAF1lQAfPsZvyA165OBwS9.I0bCgEIS7b6Gu ShLkFcOl9IeV92x2AK95Tg1_drYdSAIobuUbme.SC6R1tc0JTmjVJu6HlIFd TedvE8CrxVDnKPKh9T_U4SC13KzwH6qjR_iMqn4N_z.KPQAcSgm8XY_YIYtb v1wIYRrDDEhtFWGUrF7VQfXXRRLBcs.7jmDmsizWWPh3HmulhPU6E2Kj1cnF dqxTOj1M124gKAtX25bqQT9KikVeeVU7KgmI56vO5vmyZl4mrZFHBo9VKkmd wwJAIL7KFQr6yI6zVqSrS5aNkm4k_F.8JF12w4r6cb97P0_ehS1hQqwpwkYp 2pttgdszoFa.WfesyClSQ1Uz5i7IsMDOW203Ibrtn4G7ttOKF4Fu2PTAOX84 JrQ-- Received: from [66.68.30.169] by web111512.mail.gq1.yahoo.com via HTTP; Sat, 13 Aug 2011 11:51:43 PDT X-Mailer: YahooMailWebService/0.8.113.313619 References: Message-ID: <1313261503.45871.YahooMailNeo@web111512.mail.gq1.yahoo.com> Date: Sat, 13 Aug 2011 11:51:43 -0700 (PDT) From: Tom Walter Reply-To: Tom Walter Subject: Re: [FlyRotary] Re: vapor lock To: Rotary motors in aircraft In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-672993426-708214328-1313261503=:45871" ---672993426-708214328-1313261503=:45871 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Dennis,=0A=0AWhat fuel valve are you using?=0A=0AMy plans on the Bearhawk (= high wing taildragger):=0A=0ALeft and Right fuel lines flow into a "R-Both-= L-off" single Andair valve.=0A=0AThen to the gascolator (low point at rest)= =0A=0AGascolator feeds header tank, then into two pumps (only one in flight= ).=0A=0AEverything is under the floor of the planer, under a 0.032" 2024 fl= oor board.=0A=0AFuel return though a small "T" (0.020" orifice) to header t= ank.=0A=0AWhere does the regulator return fuel to?=A0 =0A=0A=0AWith the hig= h wing, any air bubble from the header tank should work it's way=0Aback up = the line into the tank.=A0 -6 aluminum tubing (note tanks have for and=0Aaf= t pickups, that meet up under the door.=A0 Allow for flow at high angles of= =0Aattack.=0ATom=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A_____________________________= ___=0AFrom: Dennis Havarlah =0ATo: Rotary motors = in aircraft =0ASent: Saturday, August 13, 2011= 12:41 PM=0ASubject: [FlyRotary] Re: vapor lock=0A=0A=0A =0ARight On Kelly!= !=0A=A0=0AI have the fuel system=A0Kelly described in my =0ARV-7A.=A0 I've = used Mogas with and without ethanol with outdoor temperatures =0Aup to 105 = ' F.=0A=A0=0AI have never had a vapor lock problem.=A0 After =0Astopping fo= r fuel and the engine compartment=A0 heat soaks I hear the vapors =0Abeing = pushed out of the fuel rails and thru the bypass orifice =A0when I turn =0A= on the pumps.=A0 No Hot Start Problems!!=A0 It takes less than 5 seconds = =0Afor the vapors to be removed and returned to the tank.=A0 That means tha= t all =0Athe injectors see is cool fuel when I start the engine.=A0 =0A=A0= =0AMy fuel pumps are located on the floor between the =0Apilot and passenge= r.=A0 Because the pumps are very low fuel from the left =0Atank will flow i= nto the pumps by gravity.=A0 =A0One -6 aluminum fuel line =0Afrom the pumps= runs to the firewall.=A0 If any fuel leaks during flight I =0Awill smell i= t and turn off the pumps and start gliding.=A0 If I have a leak =0Ain the e= ngine compartment I may not detect it before it ignites.=0A=A0=0AJust my tw= o cents worth.=A0 It does work for =0Ame.=0A=A0=0ADennis H.=0A=A0=0A=A0=0A= =A0=0A=A0=0A----- Original Message ----- =0A>From: Kelly Troyer =0A>To: Rot= ary motors in aircraft =0A>Sent: Saturday, August 13, 2011 9:22 AM=0A>Subj= ect: [FlyRotary] Re: vapor lock=0A>=0A>=0A>Guys,=0A>=A0=0A>I vote for keepi= ng high pressure pumps as close to the tanks and as low =0A>as possible to= fuel level...............I would not locate pumps and/or suppy=0A>hoses= =A0firewall forward unless totally encapulated,=A0insulated and cooled=0A>= by ram air...........And by all means use the bypass oriface...........Bes= ides=0A>helping to reprime pumps (as Mark says) it will relieve pressure o= n leaky=0A>injectors to prevent flooding (if you have experienced this wit= h the 13B=0A>you know what I mean and the Renesis is even worse to clear) = and to=0A>allow a vapor lock to clear the high pressure supply lines=A0fro= m=A0pump to =0A>the regulator............One more thing I would install th= e regulator after the =0A>fuel rails/injectors to allow any vapor to pass = through the rails on their way =0A>to the bypass oriface...........I have = seen some fuel regulator=A0installations =0A>with the fuel rails "Dead End= ed" after the regulator leaving vapor trapped=0A>in the rail..............= ...When flying vapor might clear with only an apparent =0A>misfire to the p= ilot but=A0after shutdown and after heat soak it could cause =0A>"Hot Star= t" problems (has anyone tryed to hot-start an fuel=A0injected=A0 "Lyc"=0A>= lately............IMHO=A0=0A>=A0=0A>Kelly Troyer=0A>"DYKE DELTA JD2" (Event= ually)=0A>"13B ROTARY"_ Engine=0A>"RWS"_RD1C/EC2/EM2=0A>"MISTRAL"_Backplate= /Oil =0A Manifold=0A>"TURBONETICS"_TO4E50 Turbo=0A>=0A>=0A>From: Ed Anders= on =0A>To: Rotary motors in aircraft =0A>Sent: Saturday, August 13, 2011 8:16 AM=0A>Subject= : [FlyRotary] Re: vapor lock=0A>=0A>=0A>No question, Charlie=A0-=A0the mor= e of your fuel line kept under EFI pump level pressures , the less chance = for vapor lock.=A0 In tank pumps certainly do that - but, as you point out= there are other considerations.=A0 Wing root sounds like a pretty good co= mpromise in luie=A0 of in-tank pumps.=A0 I considered that but in the end = decided against it as it would have high pressure fuel lines inside my coc= kpit - which I personally do not favor {:>)=0A>=A0=0A>Don't know for certa= in (and may never) the cause of the latest sputtering engine event - but, = in absence of in-tank pumps and/or return to tank - I still believe that p= ressure applied by a boost pump can prevent vapor lock (based on my own pe= rsonal experience with my unique installation)=0A>=A0=0A>Ed=0A>=0A>=0A>Fro= m: Charlie England =0A>Sent: Saturday, August 13, 2011 9:06 AM=0A>To: Rotar= y motors in aircraft =0A>Subject: [FlyRotary] Re: vapor lock=0A>=0A>The rea= lly frustrating thing about all this is that every installation is differe= nt (not to mention that it's only speculation as to what caused this parti= cular power loss).=0A>=0A>Sixties-era cars (carb, engine =0A mounted fuel = pump) had vapor lock problems all the time in hot weather. Modern =0A cars= , almost never (in-tank high pressure pump). Keeping the pumps as low =0A = & as close to the tank(s) as practical would seem to be the best path. Van = =0A recommends mounting pumps on the floor in the cabin. That means that t= he max =0A lift would be maybe 3-4 inches, through a -6 line, and nowhere = near the high =0A under-cowl temps. There's a guy flying an injected Lyc o= n ethanol-laced mogas =0A who never has a problem with vapor lock. He remo= ved the mech pump and uses =0A wingroot mounted electric pumps.=0A>=0A>If = it weren't for the maintenance =0A related inconveniences, I'd seriously c= onsider in-tank pumps, as others have =0A done.=0A>=0A>But we still don't = know whether this is what caused the recent =0A power loss....=0A>=0A>Char= lie=0A>=A0=0A>On 08/13/2011 06:20 AM, Ed Anderson =0A wrote: =0A>I should = have added - the best overall approach - returning hot fuel to the heat-si= nk tanks and drawing new cooler fuel into the lines.=0A>>=A0=0A>>Ed=0A>>= =0A>>=0A>>From: Ed Anderson =0A>>Sent: Saturday, August 13, 2011 6:47 AM=0A= >>To: Rotary motors in aircraft =0A>>Subject: [FlyRotary] Re: vapor lock=0A= >>=0A>>=0A>>Ok, Finn, =A0that was my guess as well.=A0=0A>>=A0=0A>>=A0That= then brings up a question - my understanding of "vapor lock" is that it i= s caused by a low pressure area/combined with hot fuel on the EFI pump int= ake which cause the gasoline to flash to vapor - naturally the EFI pumps c= an not pump vapor - therefore as fuel is injected from the high pressure s= ide of the pump (reducing pressure on that side), vapor can form there as = well.=A0 In any case, insufficient fuel is injected into the engine.=0A>>= =A0=0A>>Since the injectors are still clicking open, it would seem that an= y vapor on that side of the pump already has a chance to vacate the line (= through the injector)=A0- so my assessment is that it is not the relief of= vapor/gas from the high pressure side that remedies the problem, it's rem= oving the gas from the low pressure side (pump inlet) and thereby permitti= ng liquid fuel to be pumped that "cures" a vapor lock situation.=A0 =0A>>= =A0=0A>>So I am puzzled why a gas vent on the high pressure side would hav= e much (if any) effect on vapor lock.=A0 IF there is pressure on the injec= tor side - I question whether it would be as high as pump pressure - and e= ven if it were, the injector opening would provide a path for it to be rel= ease - not to mention the pressure regulator.=A0 So as I said -I'm a bit p= uzzled as to the mechanism that a vent in the high pressure side prevents = vapor lock.=0A>>=A0=0A>>In my opinion, there are two ways to reduce/elimina= te the vapor in the low pressure side - either cool the fuel sufficiently = (somewhat difficult to do) or to increase the pressure in the low pressure= line forcing the vapor back into the liquid - ergo - use=A0 a boost pump= .=0A>>=A0=0A>>FWIW=0A>>=A0=0A>>Ed=0A>>=A0=0A>>=0A>>=0A>>From: Finn Lassen = =0A>>Sent: Saturday, August 13, 2011 2:53 AM=0A>>To: Rotary motors in aircr= aft =0A>>Subject: [FlyRotary] Re: vapor lock=0A>>=0A>>Hi Ed,=0A>>=0A>>I bel= ieve it's simply a return to the tank from =0A the high-pressure side vi= a a very small orifice. How small I do not =0A know.=0A>>=0A>>Finn=0A>>= =0A>>On 8/10/2011 9:28 AM, Ed Anderson wrote: =0A>>=0A>>=A0=0A>>>The one I = potential preventive measure/fix I have not looked into is the vapor by-pa= ss/dump that I know a few folks are using.=A0 I search the archive but cou= ld not find a description of this method - anyone care to provide one?=0A= >>=0A>=0A>=0A> ---672993426-708214328-1313261503=:45871 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Dennis,

What fuel valv= e are you using?

My plan= s on the Bearhawk (high wing taildragger):

Left and Right fuel lines flow into a "R-Both-L-off" sin= gle Andair valve.

Then t= o the gascolator (low point at rest)

Gascolator feeds header tank, then into two pumps (only one in= flight).

Everything is = under the floor of the planer, under a 0.032" 2024 floor board.

Fuel return though a small "T" (0.0= 20" orifice) to header tank.

Where does the regulator return fuel to? 

Wit= h the high wing, any air bubble from the header tank should work it's way
back up the line into the tank.  -6 aluminum tubing (note tan= ks have for and
aft pickups, that meet up under the door.  A= llow for flow at high angles of
attack.

Tom






From:= Dennis Havarlah <clouduster@austin.rr.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Saturday, August 13, 2011 12:41 PM
Subject: [FlyRotary] Re: vapor lock

=0A=0A =0A =0A=0A=0A =0ARight On Kelly!!
=0A
 
=0A
I have the fuel system Kelly described in my =0ARV-7A. = ; I've used Mogas with and without ethanol with outdoor temperatures =0Aup = to 105 ' F.
=0A
&nbs= p;
=0A
I have never had a vapor lo= ck problem.  After =0Astopping for fuel and the engine compartment&nbs= p; heat soaks I hear the vapors =0Abeing pushed out of the fuel rails and t= hru the bypass orifice  when I turn =0Aon the pumps.  No Hot Star= t Problems!!  It takes less than 5 seconds =0Afor the vapors to be rem= oved and returned to the tank.  That means that all =0Athe injectors s= ee is cool fuel when I start the engine. 
=0A
 
=0A
My fuel pumps are located on the floor between the =0Apilot and = passenger.  Because the pumps are very low fuel from the left =0Atank = will flow into the pumps by gravity.   One -6 aluminum fuel line = =0Afrom the pumps runs to the firewall.  If any fuel leaks during flig= ht I =0Awill smell it and turn off the pumps and start gliding.  If I = have a leak =0Ain the engine compartment I may not detect it before it igni= tes.
=0A
 =0A
Just my two cents worth.  It = does work for =0Ame.
=0A
 
=0A
Dennis H.=0A
 
=0A
 
=0A
 
=0A
 
=0A
=0A
----- Original Message -----
= =0A
From: =0A <= a rel=3D"nofollow" title=3D"keltro@att.net" ymailto=3D"mailto:keltro@att.ne= t" target=3D"_blank" href=3D"mailto:keltro@att.net">Kelly Troyer
= =0A =0A
Sent: Saturday, August 13, 2011 9:22 =0A AM
=0A
Subject: [FlyRotary] Re: vapor lock
=0A

=0A
=0A
= Guys,
=0A
 
= =0A
I vote for keeping high =0A pressure= pumps as close to the tanks and as low
=0A
<= span style=3D"">as possible to fuel =0A level...............I would not lo= cate pumps and/or suppy
=0A
h= oses firewall forward =0A unless totally enca= pulated, insulated =0A and cooled
=0A
by ram air...........And by =0A all means use the bypass or= iface...........Besides
=0A
h= elping to reprime pumps =0A (as Mark says) it will relieve pressure on lea= ky
=0A
injectors to prevent = =0A flooding (if you have experienced this with the 13B
=0A <= div style=3D"">you know what I mean and =0A the Renesis i= s even worse to clear) and to
=0A
allow a vapor lock to clear =0A the high pressure supply lines = from pump to
=0A
the = =0A regulator............One more thing I would install the regulator afte= r =0A the
=0A
fuel rails/injectors to =0A allow any vapor to pass through the= rails on their way
=0A
to the bypass =0A oriface...........I have seen some f= uel regulator installations =0A
=0A
with the fuel rails "Dead =0A Ended" after the regulator lea= ving vapor trapped
=0A
in the= =0A rail.................When flying vapor might clear with only an apparent
=0A
misfire to the pilot =0A but after shutdown and after heat soak= it could cause
=0A
<= span style=3D"">"Hot Start" problems (has =0A anyone tryed to hot-start an= fuel injected  "Lyc"=
=0A
lately............IMHO 
=0A
=0A
 =0A
Kelly Troyer
"DYKE DELTA JD2" <= font size=3D"1">(Eventually)
=0A
"13B ROTARY"_ Engine=
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil =0A Manifold
=0A <= div>"TURBONETICS"_TO4E50 Turbo
=0A

=0A
=0A
=0A
From: Ed An= derson =0A <eanderson@carolina.rr.com>
To: Rotary motors in aircraft =0A <flyrotary@lanc= aironline.net>
Sent: = Saturday, August 13, 2011 8:16 =0A AM
Subject: [FlyRotary] Re: =0A vapor lock

=0A =
=0A
No question, Charli= e - the more of your fuel =0A line kept under EFI pump level pre= ssures , the less chance for vapor =0A lock.  In tank pumps certainly= do that - but, as you point out there are =0A other considerations. = Wing root sounds like a pretty good compromise in =0A luie  of in-ta= nk pumps.  I considered that but in the end decided =0A against it as= it would have high pressure fuel lines inside my cockpit - which =0A I pe= rsonally do not favor {:>)
=0A
 
=0A
Don't know for certain (and= may never) the cause of the =0A latest sputtering engine event - but, in = absence of in-tank pumps and/or =0A return to tank - I still believe that = pressure applied by a boost pump can =0A prevent vapor lock (based on my o= wn personal experience with my unique =0A installation)
=0A <= div> 
=0A
Ed
=0A
=0A

=0A
=0A =0A
Sent: Saturday, August 13, 2011 = 9:06 AM
=0A =0A
Subject:= [FlyRotary] Re: vapor lock
=0A

The re= ally frustrating thing about all this is that every =0A installation is di= fferent (not to mention that it's only speculation as to =0A what caused t= his particular power loss).

Sixties-era cars (carb, engine =0A moun= ted fuel pump) had vapor lock problems all the time in hot weather. Modern = =0A cars, almost never (in-tank high pressure pump). Keeping the pumps as = low =0A & as close to the tank(s) as practical would seem to be the be= st path. Van =0A recommends mounting pumps on the floor in the cabin. That= means that the max =0A lift would be maybe 3-4 inches, through a -6 line,= and nowhere near the high =0A under-cowl temps. There's a guy flying an i= njected Lyc on ethanol-laced mogas =0A who never has a problem with vapor = lock. He removed the mech pump and uses =0A wingroot mounted electric pump= s.

If it weren't for the maintenance =0A related inconveniences, I'= d seriously consider in-tank pumps, as others have =0A done.

But we= still don't know whether this is what caused the recent =0A power loss...= .

Charlie
 
On 08/13/2011 06:20 AM, Ed Anderson =0A wrot= e: =0A
=0A
I should= have added - the best overall approach - =0A returning hot fuel to the = heat-sink tanks and drawing new cooler fuel into =0A the lines.=0A
 
=0A
Ed=0A
=0A

=0A
=0A =0A
Sent: Saturday, August 13, 2011 6:47= AM
=0A =0A
Subject: [FlyRotary] Re: vapor lock
=0A

=0A
Ok, Fi= nn,  that was my guess as =0A well. 
=0A
&= nbsp;
=0A
 That then brings up a que= stion - my =0A understanding of "vapor lock" is that it is caused by a l= ow pressure =0A area/combined with hot fuel on the EFI pump intake which= cause the gasoline =0A to flash to vapor - naturally the EFI pumps can = not pump vapor - therefore =0A as fuel is injected from the high pressur= e side of the pump (reducing =0A pressure on that side), vapor can form = there as well.  In any case, =0A insufficient fuel is injected into= the engine.
=0A
 
=0A
Since the injectors are still clicking open, it would =0A seem th= at any vapor on that side of the pump already has a chance to vacate =0A = the line (through the injector) - so my assessment is that it is not = =0A the relief of vapor/gas from the high pressure side that remedies th= e =0A problem, it's removing the gas from the low pressure side (pump in= let) and =0A thereby permitting liquid fuel to be pumped that "cures" a = vapor lock =0A situation. 
=0A
 
=0A=
So I am puzzled why a gas vent on the high pr= essure =0A side would have much (if any) effect on vapor lock.  IF = there is =0A pressure on the injector side - I question whether it would= be as high as =0A pump pressure - and even if it were, the injector ope= ning would provide a =0A path for it to be release - not to mention the = pressure regulator.  So =0A as I said -I'm a bit puzzled as to the = mechanism that a vent in the high =0A pressure side prevents vapor lock.=
=0A
 
=0A
In my= opinion, there are two ways to reduce/eliminate =0A the vapor in the lo= w pressure side - either cool the fuel sufficiently =0A (somewhat diffic= ult to do) or to increase the pressure in the low pressure =0A line forc= ing the vapor back into the liquid - ergo - use  a boost =0A pump.<= /font>
=0A
 
=0A
FWIW
=0A
 
=0A
Ed
=0A
 
=0A
=0A=

=0A
=0A = =0A
Sent: Saturday, August 13, 2011 2:53 AM<= /div>=0A =0A
Subject: [F= lyRotary] Re: vapor lock
=0A

Hi Ed,
<= br>I believe it's simply a return to the tank from =0A the high-pressure= side via a very small orifice. How small I do not =0A know.

Finn=

On 8/10/2011 9:28 AM, Ed Anderson wrote:
=0A
=0A
=0A
 
=0A
The one I potential preventive measure/fix I have =0A not l= ooked into is the vapor by-pass/dump that I know a few folks are =0A u= sing.  I search the archive but could not find a description of this = =0A method - anyone care to provide =0A one?




= =0A


---672993426-708214328-1313261503=:45871--