X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from nm24.access.bullet.mail.mud.yahoo.com ([66.94.237.89] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with SMTP id 5111096 for flyrotary@lancaironline.net; Thu, 01 Sep 2011 21:15:11 -0400 Received-SPF: none receiver=logan.com; client-ip=66.94.237.89; envelope-from=ceengland@bellsouth.net Received: from [66.94.237.198] by nm24.access.bullet.mail.mud.yahoo.com with NNFMP; 02 Sep 2011 01:14:35 -0000 Received: from [66.94.237.123] by tm9.access.bullet.mail.mud.yahoo.com with NNFMP; 02 Sep 2011 01:14:35 -0000 Received: from [127.0.0.1] by omp1028.access.mail.mud.yahoo.com with NNFMP; 02 Sep 2011 01:14:35 -0000 X-Yahoo-Newman-Id: 553110.16232.bm@omp1028.access.mail.mud.yahoo.com Received: (qmail 72261 invoked from network); 2 Sep 2011 01:14:34 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bellsouth.net; s=s1024; t=1314926074; bh=B1kGVEWtObbFS0ED2snE7LKLx/VMNV0RX3pKE1deiq0=; h=X-Yahoo-Newman-Property:X-YMail-OSG:X-Yahoo-SMTP:Received:Message-ID:Date:From:User-Agent:MIME-Version:To:Subject:References:In-Reply-To:Content-Type; b=ziF8aFSzSYSlOMfJU8f08KzHstYDicQxselYLZdzvQ8d1iDb7V7u/NgrnFxWvY9Jy5h6HMYxukGiWvdoTLSnocEK04LHTZGYikUMuOL6pd5crTaaL7QABny7kN3M7+fBpyXfUfQhEUOjxxZFE/b/psq83ugD3Q5XGsIasoK4IrE= X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: fZLwn84VM1l0PwXkSrK.zalgnOKwCETdmW4ttWsWjQO9EMa PsyHcAb36vp_1_h2sA0wRyoikFp3fnu2GNVNOeRkeQ9HGFlEXDEHxJfGsk_. fLiERIwGVt7bA2odhqksFmTe0cr28CHeDy8EHSyvKFqcFZTGUapXY1ZPjkTW 9LUxoGLO.FyY4amYU7zxeN1Sa6fFgSYSF7qRMWJulGkhRY14tlm2RiWYbdNm .lUaImt.tjoeDJ_ggQoYKagpJvJ7pjwtYeTAjwRze9SaEPx4NvHqdp30mKVy WDf3VYSe6uKW8ZNJNq.x_WtsNJIWcxMG82LIkhnV04.THdmsk3gUQge.fuWe IE7_jN3dTp7phQPMLKLcbz_pFvZeOUzPYDc0WE64DbmPr.Zph7pWmL780kZZ iIFY6jDqpuOD7lauv7Y1UBXCwcItmLzI_9sJ18QfNTPLB1UlsbDcprpx0nua _JMDVxL6ZeCpntXNQseZDGiG1.x7mQrNcLEILYVf2BHx5PE0Dw75E84Ryjzf 6PTO9DRshx6ItVghUB_3WpWLx1t6mjUXlsVfFKj6r0WsF0zQq.O4Ql2rdlMo nb3gday8HuA6Tdvs23RGcg8cLKb3Vw.t4Xj5kmPHf5W9ychIxxU6.kZoFCPp giX2I5qVQ_tQ1zh9xs03j3Tuwc1lsxZ7izuyjcXRC1K2P2WUhR9jD4DUfdvw xVDzq5e9_9uvmFZ3fi_1ws88wJxUnwStsR2aIPru8dU6gzo27rahGFesDAyf M_ok- X-Yahoo-SMTP: uXJ_6LOswBCr8InijhYErvjWlJuRkoKPGNeiuu7PA.5wcGoy Received: from [192.168.10.6] (ceengland@98.95.238.145 with plain) by smtp103.sbc.mail.bf1.yahoo.com with SMTP; 01 Sep 2011 18:14:33 -0700 PDT Message-ID: <4E602DFA.4020601@bellsouth.net> Date: Thu, 01 Sep 2011 20:14:34 -0500 From: Charlie England User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.20) Gecko/20110805 Thunderbird/3.1.12 MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Pump Suck Lock? References: In-Reply-To: Content-Type: multipart/alternative; boundary="------------070008080205060006010709" This is a multi-part message in MIME format. --------------070008080205060006010709 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Here are a few examples of typical in-tank pumps: http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=ford+fuel+pump+assembly&x=0&y=0 There's typically a 'sock' type strainer on the inlet, and a mechanical bypass type pressure regulator on the pump's output, buried in that mass you see in the pics. I suspect that it is needed as a 'fuse' to prevent blowing something out if a line gets blocked somewhere downstream. A float type level sender is usually in there, too. The sump idea is unattractive to me for my my application (low wing plane) because I worry about it air-locking, unless I provide a vent back to the main tank, which is even more complicated. (I've owned a high wing homebuilt that used sumps, but they were vented back into the wing tanks.) Charlie On 09/01/2011 04:51 PM, CozyGirrrl@aol.com wrote: > 1. So there's no issues with hot soaked restarts of an EFI engine? > 2. We have a pair of Walbro GSL393 EFI pumps, suitable for in or out > of tank mounting though I am curious how they were tank mounted. > 3. Check valves. I thought that these pumps would not free flow either > direction if shut off thereby not needing check valves? > 4. If an EFI pump were mounted in a sump of approximately 1.5 qt > capacity, this fed by a low volume/low pressure Facet pump from the > main tank, between the heat generated by the pump itself and picked up > in the circuit, would the flow of the facet pump replenishing used > fuel with the excess returning to the main tank keep the pump, sump > and circuit fuel at a reasonable temp? What would the minimum volume be? > Keep in mind that the circuit fuel is mixing with the replenished fuel > so some heat is going as overflow back to the main tanks. > Chrissi & Randi > www.CozyGirrrl.com > CG Products, Custom Aircraft Hardware > Chairwomen, Sun-N-Fun Engine Workshop > In a message dated 9/1/2011 2:39:12 P.M. Central Daylight Time, > shipchief@aol.com writes: > > I'm running two of Tracy's original fuel pump offerings, in > parallel in my RV-8. I have finger strainers in the tanks, then > thru Van's fuel selector valve, forward to the pumps. The pumps > are mounted to the floor next to the left rudder pedal. Each pump > discharges thru a vertical mounted check valve on the back of the > firewall, then joins to the bulkhead fitting and on to a High > pressure filter and on to the fuel injectors, in series. The stock > Mazda pressure regulator is the last point, then to the fuel > return selector valve and to the tank. All -6 tube and hose. > I didn't like the original Van's fuel tank pick ups, so I used > John Ammter's design, which is a finger strainer in a doubler > plate at the aft lower corner of the inboard fuel tank rib. > I don't think I can get much better, unless I put a hatch in the > top of the tank and use an 'In Tank' fuel pump. Then I'll lose > some redundancy and need to change the operating proceedure...I'll > have to think about that one.... > My secondary injectors are mounted somewhat like the Cozygrrls' > lower manifold, but outboard instead of inboard of the tubes. This > is above the exhaust manifold, so I have cooling air directed in > from the left cowl inlet. It feels pretty warm in there after a > test run. > > > > -----Original Message----- > From: Ed Anderson > To: Rotary motors in aircraft > Sent: Thu, Sep 1, 2011 5:34 am > Subject: [FlyRotary] Pump Suck Lock?: [FlyRotary] Re: CG Products > Intake Manifold > > I don't see any problem with the term "vapor lock" itself - > because when the pressure on the pump inlet gets low enough, that > is exactly what happens - sufficient fuel enters a gaseous state > to interfere with the pumping of liquid fuel to the high pressure > side. So the term is not that bad a description so long as we all > realize it happens on the Low pressure (inlet) side of the pump > and NOT the high pressure side. > My experience with "vapor lock" showed that by turning my boost > pump on (adding pressure to the "suction " side of the EFI high > pressure pump) eliminated the condition - which again indicates > the problem is low pressure on the inlet side of the EFI pump. If > there were liquid there, it would be pumped, so must be vapor - so > the pump is "vapor locked" but, - not on the high pressure side. > Perhaps we should refer to a more technical accurate descriptive > name , how about "Pump Suck Lock" {:>) - just kidding. > Ed > Edward L. Anderson > Anderson Electronic Enterprises LLC > 305 Reefton Road > Weddington, NC 28104 > http://www.andersonee.com > http://www.eicommander.com > > *From:* Charlie England > *Sent:* Wednesday, August 31, 2011 3:07 PM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: CG Products Intake Manifold > > Data point: One of the big aviation engine/fuel injection > suppliers installs -4 lines everywhere in front of the firewall up > to the 'spider', on all 4 cyl Lycs (up to 200+ hp) and if memory > serves, even on the 6cyl engines (230+ hp). The individual lines > from the 'spider' to the cylinders are so small you'd be hard > pressed to get safety wire through them. This is on a Bendix style > injection system using a diaphragm type fuel pump and no return > line after the pump. These systems run at between 15 & 30 psi. > Logic is that minimum diameter line minimizes quantity of fuel > that can boil on the engine side of the firewall. > > With minimum diameter lines, as long as the pump can provide > pressure it won't take long to clear any vapor as soon as cranking > begins, or you hit Tracy's 'cold start' button a couple of times. > (Vapor in the combustion chamber is a good thing anyway, right?) :-) > > As Al Wick pointed out, the only place vapor should be a problem > is at the inlet to the pump itself. > > Charlie > > On 08/31/2011 07:35 AM, CozyGirrrl@aol.com wrote: >> Interesting Chad. >> The people flying Subes and using autogas were also guessing that >> altitude was a factor in vaporlock. We won't be using autogas due >> to variable formulation eating up epoxy tanks. >> We were thinking that if the regulator was the last item in the >> chain and that the rails were hooked up serially that it would >> minimize vaporlock and also a few seconds of the pump running >> before a hot restart would cool and clear the rail. >> Chrissi & Randi >> www.CozyGirrrl.com >> CG Products, Custom Aircraft Hardware >> Chairwomen, Sun-N-Fun Engine Workshop >> In a message dated 8/30/2011 11:36:05 P.M. Central Daylight Time, >> crobinson@medialantern.com writes: >> >> I recently researched EFI regulation a bit and found >> something interesting. Many modern (post-1995) vehicles have >> "returnless" EDI systems where the regulator is in or near >> the tank, not the engine compartment. >> It turns out this isn't for complexity reasons, though it >> does save a bit. It's for emissions. The heating of the fuel >> in the engine compartment transfers heat back to the tank. >> The tank's emissions do count even though they're not huge. >> It's also one less part, hose, and set of fittings to fail- >> and get warranty calls on. >> To deal with vapor lock they just crank up the pressure to 65 >> or more psi. Very effective. >> Not at all saying we should do the same, but the purpose is >> interesting, no? As well as the vapor lock" solution"... >> Regards, >> Chad >> > --------------070008080205060006010709 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Here are a few examples of typical in-tank pumps:
http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=ford+fuel+pump+assembly&x=0&y=0

There's typically a 'sock' type strainer on the inlet, and a mechanical bypass type pressure regulator on the pump's output, buried in that mass you see in the pics. I suspect that it is needed as a 'fuse' to prevent blowing something out if a line gets blocked somewhere downstream. A float type level sender is usually in there, too.

The sump idea is unattractive to me for my my application (low wing plane) because I worry about it air-locking, unless I provide a vent back to the main tank, which is even more complicated. (I've owned a high wing homebuilt that used sumps, but they were vented back into the wing tanks.)

Charlie

On 09/01/2011 04:51 PM, CozyGirrrl@aol.com wrote:
1. So there's no issues with hot soaked restarts of an EFI engine?
 
2. We have a pair of Walbro GSL393 EFI pumps, suitable for in or out of tank mounting though I am curious how they were tank mounted.
 
3. Check valves. I thought that these pumps would not free flow either direction if shut off thereby not needing check valves?
 
4. If an EFI pump were mounted in a sump of approximately 1.5 qt capacity, this fed by a low volume/low pressure Facet pump from the main tank, between the heat generated by the pump itself and picked up in the circuit, would the flow of the facet pump replenishing used fuel with the excess returning to the main tank keep the pump, sump and circuit fuel at a reasonable temp? What would the minimum volume be?
Keep in mind that the circuit fuel is mixing with the replenished fuel so some heat is going as overflow back to the main tanks.
 
Chrissi & Randi
www.CozyGirrrl.com
CG Products, Custom Aircraft Hardware
Chairwomen, Sun-N-Fun Engine Workshop
 
In a message dated 9/1/2011 2:39:12 P.M. Central Daylight Time, shipchief@aol.com writes:
I'm running two of Tracy's original fuel pump offerings, in parallel in my RV-8. I have finger strainers in the tanks, then thru Van's fuel selector valve, forward to the pumps. The pumps are mounted to the floor next to the left rudder pedal. Each pump discharges thru a vertical mounted check valve on the back of the firewall, then joins to the bulkhead fitting and on to a High pressure filter and on to the fuel injectors, in series. The stock Mazda pressure regulator is the last point, then to the fuel return selector valve and to the tank. All -6 tube and hose.
I didn't like the original Van's fuel tank pick ups, so I used John Ammter's design, which is a finger strainer in a doubler plate at the aft lower corner of the inboard fuel tank rib.
I don't think I can get much better, unless I put a hatch in the top of the tank and use an 'In Tank' fuel pump. Then I'll lose some redundancy and need to change the operating proceedure...I'll have to think about that one....
My secondary injectors are mounted somewhat like the Cozygrrls' lower manifold, but outboard instead of inboard of the tubes. This is above the exhaust manifold, so I have cooling air directed in from the left cowl inlet. It feels pretty warm in there after a test run.



-----Original Message-----
From: Ed Anderson <eanderson@carolina.rr.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Thu, Sep 1, 2011 5:34 am
Subject: [FlyRotary] Pump Suck Lock?: [FlyRotary] Re: CG Products Intake Manifold

I don't see any problem with the term "vapor lock" itself - because when the pressure on the pump inlet gets low enough, that is exactly what happens - sufficient fuel enters a gaseous state to interfere with the pumping of liquid fuel to the high pressure side.  So the term is not that bad a description so long as we all realize it happens on the Low pressure (inlet)  side of the pump and NOT the high pressure side. 
 
My experience with "vapor lock" showed that by turning my boost pump on (adding pressure to the "suction " side of the EFI high pressure pump) eliminated the condition - which again indicates the problem is low pressure on the inlet side of the EFI pump.  If there were liquid there, it would be pumped, so must be vapor - so the pump is "vapor locked" but, - not on the high pressure side.  
 
Perhaps we should refer to a more technical accurate descriptive name , how about  "Pump Suck Lock" {:>) - just kidding.
 
 
Ed 
 
 Edward L. Anderson
Anderson Electronic Enterprises LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com
 
 
 
 

 
Sent: Wednesday, August 31, 2011 3:07 PM
Subject: [FlyRotary] Re: CG Products Intake Manifold

Data point: One of the big aviation engine/fuel injection suppliers installs -4 lines everywhere in front of the firewall up to the 'spider', on all 4 cyl Lycs (up to 200+ hp) and if memory serves, even on the 6cyl engines (230+ hp). The individual lines from the 'spider' to the cylinders are so small you'd be hard pressed to get safety wire through them. This is on a Bendix style injection system using a diaphragm type fuel pump and no return line after the pump. These systems run at between 15 & 30 psi. Logic is that minimum diameter line minimizes quantity of fuel that can boil on the engine side of the firewall.

With minimum diameter lines, as long as the pump can provide pressure it won't take long to clear any vapor as soon as cranking begins, or you hit Tracy's 'cold start' button a couple of times. (Vapor in the combustion chamber is a good thing anyway, right?) :-)

As Al Wick pointed out, the only place vapor should be a problem is at the inlet to the pump itself.

Charlie

On 08/31/2011 07:35 AM, CozyGirrrl@aol.com wrote:
Interesting Chad.
The people flying Subes and using autogas were also guessing that altitude was a factor in vaporlock. We won't be using autogas due to variable formulation eating up epoxy tanks.
We were thinking that if the regulator was the last item in the chain and that the rails were hooked up serially that it would minimize vaporlock and also a few seconds of the pump running before a hot restart would cool and clear the rail.
 
Chrissi & Randi
www.CozyGirrrl.com
CG Products, Custom Aircraft Hardware
Chairwomen, Sun-N-Fun Engine Workshop
 
In a message dated 8/30/2011 11:36:05 P.M. Central Daylight Time, crobinson@medialantern.com writes:
I recently researched EFI regulation a bit and found something interesting. Many modern (post-1995) vehicles have "returnless" EDI systems where the regulator is in or near the tank, not the engine compartment.
It turns out this isn't for complexity reasons, though it does save a bit. It's for emissions. The heating of the fuel in the engine compartment transfers heat back to the tank. The tank's emissions do count even though they're not huge. It's also one less part, hose, and set of fittings to fail-  and get warranty calls on.
To deal with vapor lock they just crank up the pressure to 65 or more psi. Very effective.
Not at all saying we should do the same, but the purpose is interesting, no? As well as the vapor lock" solution"...
Regards,
Chad


--------------070008080205060006010709--