X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from nm2.access.bullet.mail.sp2.yahoo.com ([98.139.44.129] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with SMTP id 5091169 for flyrotary@lancaironline.net; Sat, 13 Aug 2011 15:29:33 -0400 Received-SPF: none receiver=logan.com; client-ip=98.139.44.129; envelope-from=keltro@att.net Received: from [98.139.44.101] by nm2.access.bullet.mail.sp2.yahoo.com with NNFMP; 13 Aug 2011 19:28:58 -0000 Received: from [98.139.44.68] by tm6.access.bullet.mail.sp2.yahoo.com with NNFMP; 13 Aug 2011 19:28:58 -0000 Received: from [127.0.0.1] by omp1005.access.mail.sp2.yahoo.com with NNFMP; 13 Aug 2011 19:28:58 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 561351.20760.bm@omp1005.access.mail.sp2.yahoo.com Received: (qmail 30427 invoked by uid 60001); 13 Aug 2011 19:28:58 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=att.net; s=s1024; t=1313263738; bh=82Re+BFHb56rvpnt4WjxISyaZCTAsyITWmlOOGnsC64=; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=gCYP1cVy0f7+HOP+MzVrAYJJbfjzCT6o17W08xA8dY+2yHB6LRSL8wY1GMCNGut+vfNEgDy8YX+vBjcMJZa4WPx+scCAr4gxt7A1IgZpHEzkzTu0dguoqAHzuqU5B55sR+NPkeJopaWVGKhe791hZWQrBo7svpA0WU2YDg+Xe5Q= DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=att.net; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=OqX6tKtAgDXFjQpzJZx6IRRx5H/nCM/vobF/9+UypAyslZxFyfeztMvOERxqF1IixRaDts+3FmlZJcsnQc3xShTcSkXafskbk7okf4Wthjb7qFW0BjUozdmWxfcTJ0yQQWc5cyyacJRGdzhSs0nn+MtfwPH9qn36PgmKsbPbnZ0=; X-YMail-OSG: kqG4doIVM1kIJkc7amVMVb4jGA_O8WQdTH5qxRQUnRz_LBK WypgKnTpr25YP.kj0ZwwwH8jC4X5YcctxWLqQzUEtgSA.yfF90NR._Tp3omr Jci3p_xMwTUiWB9mspdzsWAQjr1G7egaCwuRjAeyEFP4WWUOhp4U3.zROeaU 5ez25081nTBiTiF6dHSaV3Uj8J28WRSOmz3QzBXqzLcqY1MIpwZR0WpOB1dM J0tK5gdzCdjVcp62vLQAGdS315PKC8_s8_3uRqmaX3P.R4Og91WwDTWJ0rxF 8AEyfE7q_DDlbvd73Ac8uMiwdgWQQQi_bR3QlADWxUzo1XVZlyajJ7agwppt RuIDFFK7vYuBHsyoccZNWKk_YxE1DjfLqkdyl.LigxiecBHURdjZcuazafe0 mqOuu1jS0HH0DZA-- Received: from [208.114.44.181] by web83904.mail.sp1.yahoo.com via HTTP; Sat, 13 Aug 2011 12:28:58 PDT X-Mailer: YahooMailWebService/0.8.113.313619 References: Message-ID: <1313263738.12512.YahooMailNeo@web83904.mail.sp1.yahoo.com> Date: Sat, 13 Aug 2011 12:28:58 -0700 (PDT) From: Kelly Troyer Reply-To: Kelly Troyer Subject: Re: vapor lock To: Rotary motors in aircraft In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1150060462-1313263738=:12512" --0-1150060462-1313263738=:12512 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Dennis,=0A=A0=A0=A0=A0 I predict you will not have any fuel supply problems= short of a filter or pump replacement !!.............=0A=0AKelly Troyer=0A= "DYKE DELTA JD2" (Eventually)=0A"13B ROTARY"_ Engine=0A"RWS"_RD1C/EC2/EM2= =0A"MISTRAL"_Backplate/Oil Manifold=0A"TURBONETICS"_TO4E50 Turbo=0A=0AFrom:= Dennis Havarlah =0ATo: Rotary motors in aircraft= =0ASent: Saturday, August 13, 2011 12:41 PM= =0ASubject: [FlyRotary] Re: vapor lock=0A=0A=0ARight On Kelly!!=0A=A0=0AI h= ave the fuel system=A0Kelly described in my RV-7A.=A0 I've used Mogas with = and without ethanol with outdoor temperatures up to 105 ' F.=0A=A0=0AI have= never had a vapor lock problem.=A0 After stopping for fuel and the engine = compartment=A0 heat soaks I hear the vapors being pushed out of the fuel ra= ils and thru the bypass orifice =A0when I turn on the pumps.=A0 No Hot Star= t Problems!!=A0 It takes less than 5 seconds for the vapors to be removed a= nd returned to the tank.=A0 That means that all the injectors see is cool f= uel when I start the engine.=A0 =0A=A0=0AMy fuel pumps are located on the f= loor between the pilot and passenger.=A0 Because the pumps are very low fue= l from the left tank will flow into the pumps by gravity.=A0 =A0One -6 alum= inum fuel line from the pumps runs to the firewall.=A0 If any fuel leaks du= ring flight I will smell it and turn off the pumps and start gliding.=A0 If= I have a leak in the engine compartment I may not detect it before it igni= tes.=0A=A0=0AJust my two cents worth.=A0 It does work for me.=0A=A0=0ADenni= s H.=0A=A0=0A=A0=0A=A0=0A=A0=0A----- Original Message ----- =0A>From: Kelly= Troyer =0A>To: Rotary motors in aircraft =0A>Sent: Saturday, August 13, 20= 11 9:22 AM=0A>Subject: [FlyRotary] Re: vapor lock=0A>=0A>=0A>Guys,=0A>=A0= =0A>I vote for keeping high pressure pumps as close to the tanks and as low= =0A>as possible to fuel level...............I would not locate pumps and/o= r suppy=0A>hoses=A0firewall forward unless totally encapulated,=A0insulated= and cooled=0A>by ram air...........And by all means use the bypass oriface= ...........Besides=0A>helping to reprime pumps (as Mark says) it will relie= ve pressure on leaky=0A>injectors to prevent flooding (if you have experien= ced this with 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 l= ines=A0from=A0pump to =0A>the regulator............One more thing I would i= nstall the 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 "De= ad Ended" after the regulator leaving vapor trapped=0A>in the rail.........= ........When flying vapor might clear with only an apparent =0A>misfire to = the pilot but=A0after shutdown and after heat soak it could cause =0A>"Hot = Start" problems (has anyone tryed to hot-start an fuel=A0injected=A0 "Lyc"= =0A>lately............IMHO=A0=0A>=0A>Kelly Troyer=0A>"DYKE DELTA JD2" (Even= tually)=0A>"13B ROTARY"_ Engine=0A>"RWS"_RD1C/EC2/EM2=0A>"MISTRAL"_Backplat= e/Oil Manifold=0A>"TURBONETICS"_TO4E50 Turbo=0A>=0A>=0A>From: Ed Anderson <= eanderson@carolina.rr.com>=0A>To: Rotary motors in aircraft =0A>Sent: Saturday, August 13, 2011 8:16 AM=0A>Subject: [FlyR= otary] Re: vapor lock=0A>=0A>=0A>No question, Charlie=A0-=A0the more of you= r 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 compromise in= luie=A0 of in-tank pumps.=A0 I considered that but in the end decided agai= nst it as it would have high pressure fuel lines inside my cockpit - which = I personally do not favor {:>)=0A>=A0=0A>Don't know for certain (and may ne= ver) the cause of the latest sputtering engine event - but, in absence of i= n-tank pumps and/or return to tank - I still believe that pressure applied = by a boost pump can prevent vapor lock (based on my own personal experience= with my unique installation)=0A>=0A>Ed=0A>=0A>=0A>From: Charlie England = =0A>Sent: Saturday, August 13, 2011 9:06 AM=0A>To: Rotary motors in aircraf= t =0A>Subject: [FlyRotary] Re: vapor lock=0A>=0A>The really frustrating thi= ng about all this is that every installation is different (not to mention t= hat it's only speculation as to what caused this particular power loss).=0A= >=0A>Sixties-era cars (carb, engine mounted fuel pump) had vapor lock probl= ems all the time in hot weather. Modern cars, almost never (in-tank high pr= essure pump). Keeping the pumps as low & as close to the tank(s) as practic= al would seem to be the best path. Van recommends mounting pumps on the flo= or in the cabin. That means that the max lift would be maybe 3-4 inches, th= rough a -6 line, and nowhere near the high under-cowl temps. There's a guy = flying an injected Lyc on ethanol-laced mogas who never has a problem with = vapor lock. He removed the mech pump and uses wingroot mounted electric pum= ps.=0A>=0A>If it weren't for the maintenance related inconveniences, I'd se= riously consider in-tank pumps, as others have done.=0A>=0A>But we still do= n't know whether this is what caused the recent power loss....=0A>=0A>Charl= ie=0A>=A0=0A>On 08/13/2011 06:20 AM, Ed Anderson wrote: =0A>I should have a= dded - the best overall approach - returning hot fuel to the heat-sink tank= s and drawing new cooler fuel into the lines.=0A>>=0A>>Ed=0A>>=0A>>=0A>>Fro= m: 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>>O= k, Finn, =A0that was my guess as well.=A0=0A>>=0A>>=A0That then brings up a= question - my understanding of "vapor lock" is that it is caused by a low = pressure area/combined with hot fuel on the EFI pump intake which cause the= gasoline to flash to vapor - naturally the EFI pumps can not pump vapor - = therefore as fuel is injected from the high pressure side of the pump (redu= cing pressure on that side), vapor can form there as well.=A0 In any case, = insufficient fuel is injected into the engine.=0A>>=0A>>Since the injectors= are still clicking open, it would seem that any 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 press= ure side that remedies the problem, it's removing the gas from the low pres= sure side (pump inlet) and thereby permitting liquid fuel to be pumped that= "cures" a vapor lock situation.=A0 =0A>>=0A>>So I am puzzled why a gas ven= t on the high pressure side would have much (if any) effect on vapor lock.= =A0 IF there is pressure on the injector side - I question whether it would= be as high as pump pressure - and even if it were, the injector opening wo= uld provide a path for it to be release - not to mention the pressure regul= ator.=A0 So as I said -I'm a bit puzzled as to the mechanism that a vent in= the high pressure side prevents vapor lock.=0A>>=0A>>In my opinion, there = are two ways to reduce/eliminate the vapor in the low pressure side - eithe= r 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>>=0A>>FWIW=0A>>=0A>>Ed=0A>>=0A>>=0A>>=0A>>Fr= om: Finn Lassen =0A>>Sent: Saturday, August 13, 2011 2:53 AM=0A>>To: Rotary= motors in aircraft =0A>>Subject: [FlyRotary] Re: vapor lock=0A>>=0A>>Hi Ed= ,=0A>>=0A>>I believe it's simply a return to the tank from the high-pressur= e side via a very small orifice. How small I do not know.=0A>>=0A>>Finn=0A>= >=0A>>On 8/10/2011 9:28 AM, Ed Anderson wrote: =0A>>=0A>>=0A>>>=0A>>>The on= e I potential preventive measure/fix I have not looked into is the vapor by= -pass/dump that I know a few folks are using.=A0 I search the archive but c= ould not find a description of this method - anyone care to provide one?=0A= >>=0A>=0A>=0A> --0-1150060462-1313263738=:12512 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Dennis,
   &n= bsp; I predict you will not have any fuel supply problems short of a filter= or pump replacement !!.............
 
Kelly Troyer
"DYKE DELTA JD2" (Eventually)
"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil = Manifold
"TURBONETICS"_TO4E50 Turbo

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

Right On Kelly!!
 
I have the fuel system Kelly describe= d in my RV-7A.  I've used Mogas with and without ethanol with outdoor = temperatures up to 105 ' F.
 
I have never had a vapor lock problem.&nbs= p; After stopping for fuel and the engine compartment  heat soaks I he= ar the vapors being pushed out of the fuel rails and thru the bypass orific= e  when I turn on the pumps.  No Hot Start Problems!!  It ta= kes less than 5 seconds for the vapors to be removed and returned to the ta= nk.  That means that all the injectors see is cool fuel when I start t= he engine. 
 
My fuel pumps are located on the floor bet= ween the pilot and passenger.  Because the pumps are very low fuel fro= m the left tank will flow into the pumps by gravity.   One -6 alu= minum fuel line from the pumps runs to the firewall.  If any fuel leak= s during flight I will smell it and turn off the pumps and start gliding.&n= bsp; If I have a leak in the engine compartment I may not detect it before = it ignites.
 
Just my two cents worth.  It does wor= k for me.
 
Dennis H.
 
 
 
 
----- Original Message -----
Sent: Saturday, August 13, 2011 9:22= AM
Subject: [FlyRotary] Re: vapor lock<= /DIV>

Guys,
 
I vote for keeping high pressure pumps as close to the tanks and= as low
as possible to fuel level...............I would not locate pumps= and/or suppy
hoses firewall forward unless totally encapula= ted, insulated and cooled
by ram air...........And by all means use the bypass oriface....= .......Besides
helping to reprime pumps (as Mark says) it will relieve pressure= on leaky
injectors to prevent flooding (if you have experienced this with= the 13B
you know what I mean and the Renesis is even worse to clear) and= to
allow a vapor lock to clear the high pressure supply lines = from pump to
the regulator............One more thing I would install the regu= lator after the
fuel rails/injectors to allow any vapor to pass through the rail= s on their way
to the bypass oriface...........I have seen some fuel regulator&= nbsp;installations
with the fuel rails "Dead Ended" after the regulator leaving vap= or trapped
in the rail.................When flying vapor might clear with o= nly an apparent
misfire to the pilot but after shutdown and after heat soak= it could cause
"Hot Start" problems (has anyone tryed to hot-start an fuel injected  "Lyc"
lately............IMHO 
 
Kelly Troyer
"DYKE DELTA JD2" (Eventually)
"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil = Manifold
"TURBONETICS"_TO4E50 Turbo

From: Ed Anderson <eand= erson@carolina.rr.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
<= SPAN style=3D"FONT-WEIGHT: bold">Sent: Saturday, August 13, 2011= 8:16 AM
Subject: [FlyRo= tary] Re: vapor lock

No question, Charlie - the more of your f= uel line kept under EFI pump level pressures , the less chance for vapor lo= ck.  In tank pumps certainly do that - but, as you point out there are= other considerations.  Wing root sounds like a pretty good compromise= in luie  of in-tank pumps.  I considered that but in the end dec= ided against it as it would have high pressure fuel lines inside my cockpit= - which I personally do not favor {:>)
 
Don't know for certain (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 pressure applied by a boost pump c= an prevent vapor lock (based on my own personal experience with my unique i= nstallation)
 
Ed

The really frustrating thing about all this is that every in= stallation is different (not to mention that it's only speculation as to wh= at caused this particular power loss).

Sixties-era cars (carb, engin= e mounted fuel pump) had vapor lock problems all the time in hot weather. M= odern cars, almost never (in-tank high pressure pump). Keeping the pumps as= low & as close to the tank(s) as practical would seem to be the best p= ath. Van recommends mounting pumps on the floor in the cabin. That means th= at the max lift would be maybe 3-4 inches, through a -6 line, and nowhere n= ear the high under-cowl temps. There's a guy flying an injected Lyc on etha= nol-laced mogas who never has a problem with vapor lock. He removed the mec= h pump and uses wingroot mounted electric pumps.

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

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

Charlie
 
On 08= /13/2011 06:20 AM, Ed Anderson wrote:=20
I should have added - the best overall approach - r= eturning hot fuel to the heat-sink tanks and drawing new cooler fuel into t= he lines.
 
Ed

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

Ok, Finn,  that was my guess as well. 
 
 That then brings up a question - my understan= ding of "vapor lock" is that it is caused by a low pressure area/combined w= ith hot fuel on the EFI pump intake which cause the gasoline to flash to va= por - naturally the EFI pumps can not pump vapor - therefore as fuel is inj= ected from the high pressure side of the pump (reducing pressure on that si= de), vapor can form there as well.  In any case, insufficient fuel is = injected into the engine.
 
Since the injectors are still clicking open, it wou= ld seem that any vapor on that side of the pump already has a chance to vac= ate the line (through the injector) - so my assessment is that it is n= ot the relief of vapor/gas from the high pressure side that remedies the pr= oblem, it's removing the gas from the low pressure side (pump inlet) and th= ereby permitting liquid fuel to be pumped that "cures" a vapor lock situati= on. 
 
So I am puzzled why a gas vent on the high pressure= side would have much (if any) effect on vapor lock.  IF there is pres= sure on the injector side - I question whether it would be as high as pump = pressure - and even if it were, the injector opening would provide a path f= or it to be release - not to mention the pressure regulator.  So as I = said -I'm a bit puzzled as to the mechanism that a vent in the high pressur= e side prevents vapor lock.
 
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 l= ine forcing the vapor back into the liquid - ergo - use  a boost pump.=
 
FWIW
 
Ed
 

Sent: Saturday, August 13, 2011 2:53 AM
Subject: [FlyRotary] Re: vapor lock

Hi Ed,

I believe it's simply a return to the tank fro= m the high-pressure side via a very small orifice. How small I do not know.=

Finn

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






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