X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-db01.mx.aol.com ([205.188.91.95] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with ESMTP id 5110976 for flyrotary@lancaironline.net; Thu, 01 Sep 2011 17:52:24 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.91.95; envelope-from=CozyGirrrl@aol.com Received: from mtaomg-mb02.r1000.mx.aol.com (mtaomg-mb02.r1000.mx.aol.com [172.29.41.73]) by imr-db01.mx.aol.com (8.14.1/8.14.1) with ESMTP id p81Lpahv025099 for ; Thu, 1 Sep 2011 17:51:36 -0400 Received: from core-dsb004b.r1000.mail.aol.com (core-dsb004.r1000.mail.aol.com [172.29.253.13]) by mtaomg-mb02.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 522A4E000088 for ; Thu, 1 Sep 2011 17:51:36 -0400 (EDT) From: CozyGirrrl@aol.com Message-ID: <1eb73.35e04cee.3b915868@aol.com> Date: Thu, 1 Sep 2011 17:51:36 -0400 (EDT) Subject: Re: [FlyRotary] Re: Pump Suck Lock? To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_1eb73.35e04cee.3b915868_boundary" X-Mailer: AOL 9.6 sub 5004 X-Originating-IP: [69.154.217.56] x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:477278496:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d29494e5ffe6844a0 --part1_1eb73.35e04cee.3b915868_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit 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_ (http://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.andersonee.com/) _http://www.eicommander.com_ (http://www.eicommander.com/) From: _Charlie England_ (mailto:ceengland@bellsouth.net) Sent: Wednesday, August 31, 2011 3:07 PM To: _Rotary motors in aircraft_ (mailto:flyrotary@lancaironline.net) 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_ (mailto: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_ (http://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_ (mailto: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 --part1_1eb73.35e04cee.3b915868_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
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=20 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= =20 direction if shut off thereby not needing check valves?
 
4. If an EFI pump were mounted in a sump of approximately 1.5 qt capac= ity,=20 this fed by a low volume/low pressure Facet pump from the main tank, betwee= n the=20 heat generated by the pump itself and picked up in the circuit, would the f= low=20 of the facet pump replenishing used fuel with the excess returning to the m= ain=20 tank keep the pump, sump and circuit fuel at a reasonable temp? What would = the=20 minimum volume be?
Keep in mind that the circuit fuel is mixing with the replenished fuel= so=20 some heat is going as overflow back to the main tanks.
 
Chrissi &=20 Randi
www.CozyGirrrl.com
C= G=20 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,=20 shipchief@aol.com writes:
=
I'm running two of Tracy's original fuel pump offerings, in parallel= in=20 my RV-8. I have finger strainers in the tanks, then thru Van's fuel selec= tor=20 valve, forward to the pumps. The pumps are mounted to the floor next to t= he=20 left rudder pedal. Each pump discharges thru a vertical mounted check val= ve on=20 the back of the firewall, then joins to the bulkhead fitting and on = to a=20 High pressure filter and on to the fuel injectors, in series. The stock M= azda=20 pressure regulator is the last point, then to the fuel return selector va= lve=20 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= =20 Ammter's design, which is a finger strainer in a doubler plate at the aft= =20 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=20 the tank and use an 'In Tank' fuel pump. Then I'll lose some redundancy a= nd=20 need to change the operating proceedure...I'll have to think about that= =20 one....
My secondary injectors are mounted somewhat like the Cozygrrls' lowe= r=20 manifold, but outboard instead of inboard of the tubes. This is above the= =20 exhaust manifold, so I have cooling air directed in from the left co= wl=20 inlet. It feels pretty warm in there after a test run.



---= --Original=20 Message-----
From: Ed Anderson <eanderson@carolina.rr.com>
To= :=20 Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Th= u,=20 Sep 1, 2011 5:34 am
Subject: [FlyRotary] Pump Suck Lock?: [FlyRotary] = Re:=20 CG Products Intake Manifold

I don't see any problem with the term "vapor lock= "=20 itself - because when the pressure on the pump inlet gets low enough, tha= t is=20 exactly what happens - sufficient fuel enters a gaseous state t= o=20 interfere with the pumping of liquid fuel to the high pressure side. = ; So=20 the term is not that bad a description so long as we all realize it happe= ns on=20 the Low pressure (inlet)  side of the pump and NOT the high pressure= =20 side. 
 
My experience with "vapor lock" showed that by tu= rning=20 my boost pump on (adding pressure to the "suction " side of the EFI high= =20 pressure pump) eliminated the condition - which again indicates the probl= em is=20 low pressure on the inlet side of the EFI pump.  If there were= =20 liquid there, it would be pumped, so must be vapor - so the pump is "vapo= r=20 locked" but, - not on the high pressure side.  
 
Perhaps we should refer to a more technical accur= ate=20 descriptive name , how about  "Pump Suck Lock" {:>) - just kidding.
 
 
Ed 
 
 Edward L.=20 Anderson
Anderson Electronic Enterprises LLC
305 Reefton=20 Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com
 
 
 
 

 
From: Charlie England
Sent: Wednesday, August 31, 2011 3:07 PM
Subject: [FlyRotary] Re: CG Products Intake=20 Manifold

Data point: One of the big aviation engine/fuel injection= =20 suppliers installs -4 lines everywhere in front of the firewall up to the= =20 'spider', on all 4 cyl Lycs (up to 200+ hp) and if memory serves, even on= the=20 6cyl engines (230+ hp). The individual lines from the 'spider' to the=20 cylinders are so small you'd be hard pressed to get safety wire through t= hem.=20 This is on a Bendix style injection system using a diaphragm type fuel pu= mp=20 and no return line after the pump. These systems run at between 15 & = 30=20 psi. Logic is that minimum diameter line minimizes quantity of fuel that = can=20 boil on the engine side of the firewall.

With minimum diameter li= nes,=20 as long as the pump can provide pressure it won't take long to clear any = vapor=20 as soon as cranking begins, or you hit Tracy's 'cold start' button a coup= le of=20 times. (Vapor in the combustion chamber is a good thing anyway, right?)= =20 :-)

As Al Wick pointed out, the only place vapor should be a probl= em is=20 at the inlet to the pump itself.

Charlie

On 08/31/2011 07:3= 5 AM,=20 CozyGirrrl@aol.com wrote:=20
Interesting Chad.
The people flying Subes and using autogas were also guessing that= =20 altitude was a factor in vaporlock. We won't be using autogas due to=20 variable formulation eating up epoxy tanks.
We were thinking that if the regulator was the last item in the ch= ain=20 and that the rails were hooked up serially that it would minimize vapor= lock=20 and also a few seconds of the pump running before a hot restart would c= ool=20 and clear the rail.
 
Chrissi & Randi
www.CozyGirrrl.com
CG Products, Custom Aircraft= =20 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=20 writes:
I recently researched EFI regulation a bit and found something= =20 interesting. Many modern (post-1995) vehicles have "returnless" EDI= =20 systems where the regulator is in or near the tank, not the engine=20 compartment.
It turns out this isn't for complexity reasons, though it does s= ave a=20 bit. It's for emissions. The heating of the fuel in the engine compar= tment=20 transfers heat back to the tank. The tank's emissions do count even t= hough=20 they're not huge. It's also one less part, hose, and set of fittings = to=20 fail-  and get warranty calls on.
To deal with vapor lock they just crank up the pressure to 65 or= more=20 psi. Very effective.
Not at all saying we should do the same, but the purpose is=20 interesting, no? As well as the vapor lock" solution"...
Regards,
Chad

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