Return-Path: <13brv3@bellsouth.net> Received: from imf16aec.mail.bellsouth.net ([205.152.59.64] verified) by logan.com (CommuniGate Pro SMTP 4.1.5) with ESMTP id 2633702 for flyrotary@lancaironline.net; Sun, 12 Oct 2003 10:57:49 -0400 Received: from rad ([68.212.14.231]) by imf16aec.mail.bellsouth.net (InterMail vM.5.01.05.27 201-253-122-126-127-20021220) with ESMTP id <20031012145806.EJSR1781.imf16aec.mail.bellsouth.net@rad> for ; Sun, 12 Oct 2003 10:58:06 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: EWP - series pumps and wacky ideas Date: Sun, 12 Oct 2003 09:57:49 -0500 Message-ID: <000001c390d1$34784e10$0101a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C390A7.4BA24610" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C390A7.4BA24610 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable After reading Davies Craig reply I'm considering a series installation as it would allow for redundancy without the addition of another possible failure mode from the T/flapper valve. My only concern = is that I've worked hard to reduce or eliminate all possible restrictions = to my system and am loathe to introduce another by having a standby pump in = the line. However it would be simple for me to measure any change as I have = a flow meter. =20 Hi Todd. It does sound like series is the way to go. Tell us more = about this flow meter. If adding a second pump for a backup, you'll have to = know immediately if the first one quits working. I'm thinking that you will likely damage the engine, or at least lose a large amount of coolant if = you don't get the second pump on ASAP. Ideally, there would be a downstream pressure switch, or something hooked into you flow meter to turn on the second pump automatically. =20 =20 The other option is to just run them all the time, which is probably = what I'll plan to do. The plan would be to have a pressure sensor downstream = of the pumps. During pre-flight, before cranking the engine, I can turn = each pump on by itself, and verify that I hear it, and that it increases the pressure. Even with the engine running, you may be able to see a slight drop in the pressure when turning the pumps off one at a time. Of = course, to see this... (whining about not having an EM-2 deleted) :-) =20 FWIW, this is the same philosophy that I use with my fuel pumps. I = check them individually as a pre-flight item, then run them both during = flight. My reasoning for this is to virtually eliminate the possibility of an in-flight fuel pump emergency. I'd MUCH rather find out that one of my pumps has died while I'm safely on the ground, than to experience the anxiety of having the engine quit in flight. The other plus is = eliminating emergency checklist items. If all your backup systems are already = running, and the engine quits, you might as well just concentrate on landing dead stick. The only downsides are a bit more current draw, and wear and = tear on the pumps. If the alt fails, I'll turn off one fuel pump, and one = EWP to save some energy. If I have to replace the pumps within a few years, = big deal. It'll be the cheapest thing I've done on this plane :-)=20 Everything that I removed from my old mechanical system totalled 12lbs, so even with an additional pump weight is still half. =20 I figure the pump itself is the majority of the weight. The housing is = only supposed to weigh about 3.5 lbs, maybe 4 - 4.5 lbs with the bolts. My current thinking is that I won't save that much weight by removing the = water pump housing, especially since you have to add an adapter fitting for = the water flow to the block, along with an alternator mount of some type. = I'm going to look into just covering the water pump hole with a plate, and keeping the housing for all of it's other uses. This realization was = the key to allowing me to go ahead and order the EWP's. =20 =20 The other key was thinking of a potential place to mount the pumps. (Warning, unusual idea follows) I plan to keep my radiator below the engine, and at the very rear of the engine compartment. This takes advantage of space in the cowl that is normally used for air exit, and exhaust pipes. The rear, bottom edge of the cowling in an RV is a few inches below the bottom of the firewall. Van even recesses part of the fuselage in this area as well, to create more of an opening. My = radiator will probably require that I lower the rear of the stock cowl an inch or = so on top of that. Now, this leaves me with a pretty large space on the = bottom of fuselage, just behind the cowling, that will eventually get a fairing = to cover it. I've tried to think of things to put here, but since the rear radiator tank blocks most of the opening, I can't get any significant = size hose through here. (At this point, anyone who can figure out what I'm = going to propose, can have the next room in the loony bin.) =20 Because I'm moving the new radiator back as far as possible, the tank = ends up being under the rear motor mount tubing. I figure that makes it impossible to put hoses in or out of that tank, so the plan was to make = this a double pass radiator. Now, the front tank will be two separate tanks, with water going into one, and out of the other. All it will do in the = rear tank is flow from one side of the radiator to the other. (You're = getting less points if you figure it out now). =20 So now, I have a big space behind the radiator, with full access to the = end of the rear tank. I also have no water pump. What if I make the rear = tank two separate tanks, just like the front tank is? Now, it's effectively = two radiators, side by side (take note evap guys). The plan, is to put the = two EWPs in series, in the empty space behind the radiator. I would draw = water from one of the rear tanks, and flow it back into the other tank, = completing the circuit. =20 =20 OK, here's the part where you all burst my balloon, and tell me why this won't work. Go ahead, take your best shot :-) =20 Cheers, Rusty (I hear sirens...and why are the sleeves so long on this coat) = =20 ------=_NextPart_000_0001_01C390A7.4BA24610 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

        After = reading Davies=20 Craig reply I'm considering a series installation as it would allow for=20 redundancy without the addition of another possible failure mode from = the=20 T/flapper valve. My only concern is that I've worked hard to reduce or = eliminate=20 all possible restrictions to my system and am loathe to introduce = another by=20 having a standby pump in the line. However it would be simple for me to = measure=20 any change as I have a flow meter.

 
Hi = Todd.  It does=20 sound like series is the way to go.  Tell us more about this flow=20 meter.  If adding a second pump for a backup, you'll have = to=20 know immediately if the first one quits working.  I'm = thinking=20 that you will likely damage the engine, or at least lose a large amount = of=20 coolant if you don't get the second pump on ASAP.  Ideally, = there=20 would be a downstream pressure switch, or something hooked into you = flow=20 meter to turn on the second pump=20 automatically.   
 
The = other option is to=20 just run them all the time, which is probably what I'll plan to = do. =20 The plan would=20 be to have a pressure sensor downstream of the pumps.  During = pre-flight,=20 before cranking the engine, I can turn each pump on by itself, and = verify that I=20 hear it, and that it increases the pressure.  Even with the engine = running,=20 you may be able to see a slight drop in the pressure when turning the = pumps off=20 one at a time.  Of course, to see this... (whining about not = having an=20 EM-2 deleted) :-)
 
FWIW, this is the same = philosophy that I use=20 with my fuel pumps.  I check them individually as a=20 pre-flight item, then run them both during flight.  My reasoning = for this=20 is to virtually eliminate the possibility of an in-flight fuel=20 pump emergency.  I'd MUCH rather find out that one of my = pumps=20 has died while I'm safely on the ground, than to experience the = anxiety of=20 having the engine quit in flight.  The other plus is eliminating = emergency=20 checklist items.  If all your backup systems are already = running, and=20 the engine quits, you might as well just concentrate on landing dead=20 stick.   The only downsides are a bit more current draw, = and wear=20 and tear on the pumps.  If the alt fails, I'll turn off one = fuel pump,=20 and one EWP to save some energy.  If I have to replace the pumps = within a=20 few years, big deal.  It'll be the cheapest thing I've = done on=20 this plane :-) 

        Everything that I = removed=20 from my old mechanical system totalled 12lbs, so even with an additional = pump=20 weight is still half.
 
I figure the pump = itself is the=20 majority of the weight.  The housing is only supposed to weigh = about=20 3.5 lbs, maybe 4 - 4.5 lbs with the bolts.  My current = thinking is=20 that I won't save that much weight by removing the water pump = housing,=20 especially since you have to add an adapter fitting for the water flow = to=20 the block, along with an alternator mount of some = type.  I'm=20 going to look into just covering the water pump hole with a plate, and = keeping=20 the housing for all of it's other uses.  This realization = was the=20 key to allowing me to go ahead and order the=20 EWP's.  
 
The other key  was = thinking of a=20 potential place to mount the pumps.    (Warning, unusual = idea=20 follows)   I plan to keep my radiator below the = engine,=20 and at the very rear of the engine compartment.  This takes = advantage=20 of space in the cowl that is normally used for air exit, and = exhaust=20 pipes.  The rear, bottom edge of the cowling in an RV = is a=20 few inches below the bottom of the firewall.  Van even = recesses part=20 of the fuselage in this area as well, to create more of an=20 opening.  My radiator will probably require that I lower the = rear of=20 the stock cowl an inch or so on top of that.  Now, this leaves me = with a=20 pretty large space on the bottom of fuselage, just behind the cowling, that will = eventually get=20 a fairing to cover it.  I've tried to think of things to put here, = but=20 since the rear radiator tank blocks most of the opening, I can't = get any=20 significant size hose through here.  (At this point, anyone = who can=20 figure out what I'm going to propose, can have the next room = in the=20 loony bin.)
 
Because I'm moving the = new radiator=20 back as far as possible, the tank ends up being under the = rear motor=20 mount tubing.  I figure that makes it impossible to put hoses = in or=20 out of that tank, so the plan was to make this a double pass = radiator. =20 Now, the front tank will be two separate tanks, with water going = into one,=20 and out of the other.  All it will do in the rear tank is flow = from=20 one side of the radiator to the other.  (You're getting less points = if you=20 figure it out now).
 
So now, I have a big = space behind the=20 radiator, with full access to the end of the rear tank.  I = also have=20 no water pump.  What if I make the rear tank two separate tanks, = just like=20 the front tank is?  Now, it's effectively two radiators, side by = side (take=20 note evap guys).  The plan, is to put the two = EWPs in=20 series, in the empty space behind the radiator.  I would draw water = from=20 one of the rear tanks, and flow it back into the other tank, completing = the=20 circuit.  
 
OK, here's the part = where you all=20 burst my balloon, and tell me why this won't work.  Go ahead, take = your=20 best shot :-)
 
Cheers,
Rusty (I hear = sirens...and why are=20 the sleeves so long on this coat)       
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