X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-fx0-f52.google.com ([209.85.161.52] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with ESMTPS id 5098519 for flyrotary@lancaironline.net; Sat, 20 Aug 2011 14:38:48 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.161.52; envelope-from=msteitle@gmail.com Received: by fxd18 with SMTP id 18so2494715fxd.25 for ; Sat, 20 Aug 2011 11:38:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=6Em96vWEyxPUAcT1cVC8yGYMzRgbajnrncp/cUI1xM8=; b=b/AjQG9C8cKo9m4L6507S9znU18/Fzx4HSjdL5pECnbnmqodtZ7oh/Do7d0k8370uM cHGTA85qP0ihtxcxiQHplo32Q6SNH7WEoDlLEujypNolcoArKFYIeVXVnF/JduYyec/k sdUqW+aQO/s8sfNXxsZSF84zTfHZF1pX0Ptfg= MIME-Version: 1.0 Received: by 10.223.99.91 with SMTP id t27mr1082724fan.56.1313865489715; Sat, 20 Aug 2011 11:38:09 -0700 (PDT) Received: by 10.223.74.129 with HTTP; Sat, 20 Aug 2011 11:38:09 -0700 (PDT) In-Reply-To: References: Date: Sat, 20 Aug 2011 13:38:09 -0500 Message-ID: Subject: Re: [FlyRotary] Re: Dennis Haverlah Fuel System...or any others, for that matter. From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=000e0cd1d736cc10a604aaf425dd --000e0cd1d736cc10a604aaf425dd Content-Type: text/plain; charset=ISO-8859-1 Kelly, Well, it depends on how full the tanks are at the time. ;-) The Lancair ES is a low wing airframe with wet wings. So, the lowest location is the fuse floor which is where I put them. Fuel level will be above the pumps when full, or at the very worst situation (approaching empty), level with the pumps. Also, the wings have significant dihedral, so the difference increases considerably when tanks are full. Mark On Sat, Aug 20, 2011 at 12:16 PM, Kelly Troyer wrote: > Mark, > Where is your fuel level relative to the pumps.......... > > Kelly Troyer > *"DYKE DELTA JD2" (Eventually)* > "13B ROTARY"_ Engine > "RWS"_RD1C/EC2/EM2 > "MISTRAL"_Backplate/Oil Manifold > "TURBONETICS"_TO4E50 Turbo > > *From:* Mark Steitle > *To:* Rotary motors in aircraft > *Sent:* Friday, August 19, 2011 2:46 PM > *Subject:* [FlyRotary] Re: Dennis Haverlah Fuel System...or any others, > for that matter. > > Al, > > Yes, the inlet filters are coarse screen, one per tank. > > Mark > > On Fri, Aug 19, 2011 at 2:13 PM, Al Wick wrote: > > ** > Mark said: > Way to be. Glad you went to the effort to test it. Others might have been > tempted to respond just by cracking the fitting on fuel rail. Fuel starts to > flow: "Took care that problem". You pursued further so that running one tank > dry is not catastrophic. > > Top view of your diagram looks good. It's the fine details that make a > difference. Some plumbing oversight prevented your pumps from getting wet. > I do hope those two inlet filters are coarse ones with low pressure drop > and high surface area. You can't beat the oem inlet filter bags. > > -al wick > > ----- Original Message ----- > *From:* Mark Steitle > *To:* Rotary motors in aircraft > *Sent:* Wednesday, August 17, 2011 11:46 AM > *Subject:* [FlyRotary] Re: Dennis Haverlah Fuel System...or any others, > for that matter. > > Al, > > You wrote,*"You also test it without the bleed line?"** * > > Yes, the test led to the search for a solution. You can see the "bypass > circuit" on Egg's fuel system schematic at > http://www.eggenfellneraircraft.com/Manual-Updates/EarlyManualFuel.html. > This is what I incorporated into my fuel system, and it solved the problem. > Its been quite a few years now, but I may still have some of the posts on > the Eggenfellner list that occurred in search for this as the final > solution. > > You wrote,*"FWIW, everything you describe is not vapor lock, has nothing > to do with vapor lock." * > > As I said, I'm not sure if my condition fits the definition of "vapor > lock", but that's what someone labeled it, and it stuck. The problem is > that EFI pumps don't draw or push air very well. So, if the flowing fuel is > replaced by air due to an empty tank, the pump keeps running, but > essentially stops pumping fuel. With a 40# spring in the downstream > circuit, it is virtually impossible for the pump to pass the air even > though the selector valve has been swiched to the full tank. I would agree > that the fuel injectors should be able to pass the air, provided the prop is > still turning. (This was not the case with my ground test.) The bypass > circuit ensures that flow will be restored as soon as the bubble passes > through the pump and the fuel pump regains its prime. > > Mark S. > > On Wed, Aug 17, 2011 at 12:06 PM, Al Wick wrote: > > ** > low as possible > > Instead of speculations, you can actually measure how good it is. A pump, > clear fuel lines, and water instead of fuel. Pinch fuel line with pliers to > increase pressure drop. Watch bubbles come out of solution. Hear the rattle > from pump due to it's inability to flow air. > If you also put a pressure gage on pump inlet, you can see how fine fuel > filter increases risk. You can see how small diameter tubing increases risk, > heat, head pressure, etc etc. > > Egg had one forced landing. It was caused by vapor lock. Absolutely NOTHING > to do with the lack of bleed line. A day later, Jan made it to the crash > site. Pump would not flow fuel until he cracked the line loose. This is > simply because the inlet to pumps was not wet. He did not understand this. > He just reacted to symptoms. Nothing to do with vapor lock. Remember, this > was crash site. Who knows what attitude plane was at. As I described, if you > screwed up your plumbing from tank to pump, then pump is not self priming. > > You also test it without the bleed line? > > FWIW, everything you describe is not vapor lock, has nothing to do with > vapor lock. > > -al wick > > > ----- Original Message ----- > *From:* Mark Steitle > *To:* Rotary motors in aircraft > *Sent:* Wednesday, August 17, 2011 9:19 AM > *Subject:* [FlyRotary] Re: Dennis Haverlah Fuel System...or any others, > for that matter. > > Al, > > I would think that a well-designed fuel system with the pumps located as > low as possible, in a cool area, and a return system should not be troubled > with vapor locking. Although I guess it could happen in Death Valley > in August if the a/c is left out in the sun for 8 hours, and running auto > gas. So far, I haven't had any problem here in Texas (temps 105* today). > > > My purpose for installing the bypass circuit was more critical to safe > flight. (The solution was the result of a forced landing, or two, in an > Eggenfellner Subaru installation.) During ground runs, using a 5-gallon > can, I found that the efi fuel pumps could not restore pressure once the > tank had been allowed to run dry. When this occurred, the EFI pump would > suck a big slug of air into the inlet side of the pump, loose pressure, and > being unable to build psi equal to the pressure regulator setting, it would > stop pumping fuel (vapor lock). The only way to restore operation was to > crack open the system downstream of the pump until the slug of air could be > passed on through the fuel pump. Not sure this meets your definiton of > "vapor lock", but I think it does, but for a different reason than fuel > vapor pressure. > > I have tested this system on the ground and it works as advertized. If the > tank runs dry, switched to a full tank, the efi pump will restore pressure > to the system within a few seconds. I urge all builders to run this test on > their fuel system to determine whether or not their pumps are able to > restore pressure after running a tank dry. Or, just don't ever run a tank > dry. > > Mark S. > > > > On Wed, Aug 17, 2011 at 10:22 AM, Ernest Christley wrote: > > Al Wick wrote: > > I'm really concerned for some of these fuel designs. The fuel bleed has > nothing to do with vapor lock. Virtually no effect at all. > > > > I don't know why others are doing it, but for me, the bleed has nothing at > all to do with vapor lock. Some conversations have been mixed together, so > I can see how that could be the impression. The point of the pressure bleed > is to bleed off the pressure after shutdown. > > I have a strong, positive head pressure going into my pumps. They, and the > regulator, are about 8" directly below the tank. Excess fuel goes back to > the opposite side of the tank from the pickup, and a single line goes > forward to feed the injectors. The fuel lines are arranged such that heat > soaking the lines to the point of boiling the gas will push liquid fuel down > hill and behind the firewall, isolating the gaseous gas with its heat at the > top of the line. Turning the pumps on will pressurize the line to 55psi, > returning most of the gaseous fuel back to a liquid state. The ECM is > programmed for a longer clearing pulse on hot start. > > The point of the bleed is to allow fuel to move back to the tank. I had > the issue of a the pressurized lines being perfectly sealed. The > pressurized fuel was finding the path of least resistance out, which just > happened to be out the injector and into the intake manifold where it sat as > a little puddle. Heat soaking the lines would not push liquid fuel downhill > and back behind the firewall. It would push more fuel into the manifold. A > puddle of gas sitting in a composite manifold, just above a hot exhaust > stack is just bad mojo. A poorly sealed regulator allows the pressure to > bleed off in about 5 seconds (give or take), isolating the hot fuel in front > of the firewall, and keeping the rest cool and out of the intake manifold. > > Got nuthin' to do with vapor lock. > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net:** > 81/lists/flyrotary/List.html > > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > > > > > --000e0cd1d736cc10a604aaf425dd Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Kelly,=A0

Well, it depends on how full the tanks are at = the time. =A0;-)

The Lancair ES is a low wing airframe w= ith wet wings. =A0So, the lowest location is the fuse floor which is where = I put them. =A0Fuel level will be above the pumps when full, or at the very= worst situation (approaching empty), level with the pumps. =A0Also, the wi= ngs have significant dihedral, so the difference increases considerably whe= n tanks are full.

Mark

On = Sat, Aug 20, 2011 at 12:16 PM, Kelly Troyer <keltro@att.net> wrote:
Mark,
=A0=A0=A0 Where is your=A0fuel level relative to the = pumps..........
=A0
Kelly Troyer
"DYKE DELTA JD2" = (Eventually)
"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
&quo= t;MISTRAL"_Backplate/Oil Manifold
"TURBONETICS"_TO4E50 Turbo

From: Mark Steitle <= ;msteitle@gmail.com= >
To: Rotary motor= s in aircraft <flyrotary@lancaironline.net>
Sent: Friday, August 19, 201= 1 2:46 PM
Subject: [FlyRo= tary] Re: Dennis Haverlah Fuel System...or any others, for that matter.

Al,=A0

Yes, the inlet filters are coarse screen, one per tank. =A0

Mark

On Fri, Aug 19, 2011 at 2:13 PM, Al Wick <alwick@juno.= com> wrote:
Mark said:
<Yes, the test led to the search for a solution
Way to be. Glad you went to the effort to test it. Others might have b= een tempted to respond just by cracking the fitting on fuel rail. Fuel star= ts to flow: "Took care that problem". You pursued further so that= running one tank dry is not catastrophic.
=A0
Top view of your diagram looks good. I= t's the fine details that make a difference. Some plumbing oversight pr= evented your pumps from getting wet.
I do hope those two inlet filters are = coarse ones with low pressure drop and high surface area. You can't bea= t the oem inlet filter bags.
=A0
-al wick
----- Original Message -----
Sent: Wednesday, August 17, 2011 11:4= 6 AM
Subject: [FlyRotary] Re: Dennis Haver= lah Fuel System...or any others, for that matter.

Al,
=A0
You wrote,"You also test it without the bleed line?&qu= ot;=A0
=A0
Yes, the test led to the search for a solution.=A0 You can see the &qu= ot;bypass circuit" on Egg's fuel system schematic at http://www.eggenfellneraircraft.com/Manual-= Updates/EarlyManualFuel.html.=A0 This is=A0what I=A0incorporated into m= y=A0fuel system, and it solved the problem.=A0 Its been quite a few years n= ow, but I=A0may still have=A0some of the posts on the Eggenfellner=A0list= =A0that occurred in search for this as the final solution.
=A0
You wrote,"FWIW, everything you describe is not vapo= r lock, has nothing to do with vapor lock."=A0
=A0
As I said, I'm not sure if my condition fits the definition of &qu= ot;vapor lock", but that's what someone labeled it, and it stuck.= =A0 The problem is that EFI pumps don't=A0draw or push air very well.= =A0 So, if the flowing fuel is replaced by air due to an empty tank, the pu= mp keeps running, but essentially=A0stops pumping fuel.=A0 With a 40# sprin= g in the downstream circuit, it is virtually impossible for the pump to pas= s the air=A0even though=A0the selector valve has been swiched to the full t= ank.=A0 I would agree that the fuel injectors should be able to pass the ai= r, provided the prop is still turning.=A0 (This was not the case with my gr= ound test.) The bypass circuit ensures that flow will=A0be restored as soon= as the bubble=A0passes through the pump and=A0the fuel pump regains its pr= ime.=A0
=A0
Mark S.

On Wed, Aug 17, 2011 at 12:06 PM, Al Wick <alwick@juno= .com> wrote:
<I would think that a well-designed fuel system with the pumps loca= ted as low as possible
=A0
Instead of speculations, you can actua= lly measure how good it is. A pump, clear fuel lines, and water instead of = fuel. Pinch fuel line with pliers to increase pressure drop.=A0 Watch bubbl= es come out of solution. Hear the rattle from pump due to it's inabilit= y to flow air.
If you also put a pressure gage on pum= p inlet, you can see how fine fuel filter increases risk. You can see how s= mall diameter tubing increases risk, heat, head pressure, etc etc. <= /div>
=A0
<the result of a forced landing
Egg had one forced landing. It was caused by vapor lock. Absolutely NO= THING to do with the lack of bleed line. A day later, Jan made it to the cr= ash site. Pump would not flow fuel until he cracked the line loose. This is= simply because the inlet to pumps was not wet. He did not understand this.= He just reacted to symptoms. Nothing to do with vapor lock. Remember, this= was crash site. Who knows what attitude plane was at. As I described, if y= ou screwed up your plumbing from tank to pump, then pump is not self primin= g.
=A0
<tested this system on the ground and it works as advertized
<= /div>
You also test it without the bleed line?
=A0
FWIW, everything you describe is not v= apor lock, has nothing to do with vapor lock.
=A0
-al wick
=A0
----- Original Message -----
Sent: Wednesday, August 17, 2011 9:19= AM
Subject: [FlyRotary] Re: Dennis Haver= lah Fuel System...or any others, for that matter.

Al,
=A0
I would think that a well-designed=A0fuel system=A0with the pumps loca= ted as low as possible, in a=A0cool area,=A0and=A0a return system=A0should = not be troubled with vapor locking.=A0=A0Although I guess it could happen i= n Death Valley in=A0August if the a/c is left out in the sun for 8 hours, a= nd running auto gas.=A0 So far, I haven't had any problem here in Texas= (temps 105* today).=A0 =A0
=A0
My purpose for installing the bypass circuit was more critical to safe= flight.=A0 (The solution was=A0the result of a forced landing, or two,=A0i= n an Eggenfellner Subaru installation.)=A0 During ground runs, using a 5-ga= llon can, I found that the efi fuel pumps could not restore pressure once t= he tank had been allowed to run dry.=A0=A0When this occurred, the EFI pump= =A0would suck a big slug of air into the inlet side of the pump, loose pres= sure,=A0and being unable to build psi equal to the pressure regulator setti= ng, it would stop pumping fuel (vapor lock).=A0 The only way to restore ope= ration was to crack open the system downstream of the pump until the slug o= f air could be passed on through the fuel pump.=A0=A0Not sure this meets yo= ur definiton of "vapor lock", but I think it does, but for a diff= erent reason than fuel vapor pressure.
=A0
I have tested this system on the ground and it works as advertized.=A0= If the tank runs dry, switched to a full tank, the efi pump will restore p= ressure to the system within a few seconds.=A0 I urge all builders to run t= his test on their fuel system to determine whether or not their pumps are a= ble to restore pressure after running a tank dry.=A0 Or, just don't eve= r run a tank dry.
=A0
Mark S.


=A0
On Wed, Aug 17, 2011 at 10:22 AM, Ernest Christley &= lt;echristley@att.net> wrote:
Al Wick wrote:
I'm really concerned for some of these fuel designs. Th= e fuel bleed has nothing to do with vapor lock. Virtually no effect at all.=
=A0

I don't know why others are doing it, but= for me, the bleed has nothing at all to do with vapor lock. =A0Some conver= sations have been mixed together, so I can see how that could be the impres= sion. =A0The point of the pressure bleed is to bleed off the pressure after= shutdown.

I have a strong, positive head pressure going into my pumps. =A0They, a= nd the regulator, are about 8" directly below the tank. =A0Excess fuel= goes back to the opposite side of the tank from the pickup, and a single l= ine goes forward to feed the injectors. =A0The fuel lines are arranged such= that heat soaking the lines to the point of boiling the gas will push liqu= id fuel down hill and behind the firewall, isolating the gaseous gas with its heat at t= he top of the line. =A0Turning the pumps on will pressurize the line to 55p= si, returning most of the gaseous fuel back to a liquid state. =A0The ECM i= s programmed for a longer clearing pulse on hot start.

The point of the bleed is to allow fuel to move back to the tank. =A0I = had the issue of a the pressurized lines being perfectly sealed. =A0The pre= ssurized fuel was finding the path of least resistance out, which just happ= ened to be out the injector and into the intake manifold where it sat as a = little puddle. =A0Heat soaking the lines would not push liquid fuel downhil= l and back behind the firewall. =A0It would push more fuel into the manifol= d. =A0A puddle of gas sitting in a composite manifold, just above a hot exh= aust stack is just bad mojo. =A0A poorly sealed regulator allows the pressu= re to bleed off in about 5 seconds (give or take), isolating the hot fuel in front of the firewall, and keeping the rest cool and out o= f the intake manifold.

Got nuthin' to do with vapor lock.

--
Homepage: =A0http://www.flyrotary.com/
Archive and UnSub: =A0 http://mail.lancairon= line.net:81/lists/flyrotary/List.html


--
Homepage:=A0 http://www.flyrotary.com/
Archive and UnSub:= =A0=A0 http://mail.lancaironline.net:81/list= s/flyrotary/List.html



<= /div>

--000e0cd1d736cc10a604aaf425dd--