KR> Facet pumps in series
I've been thinking about this idea of not having a mechanical fuel pump on a VW aircraft engine. There are several planes that dispense with it in favor of the electric pump because the pump in the stock position can cause a bump on the cowling. This seems dubious from a reliability standpoint, which is why so many people have multiple electric fuel pumps, backup power supplies, etc. But an idea occurred to me. I had to replace a fuel pump 30 years or so ago on my VW Beetle, and the pump is operated by a bump on the camshaft. As the camshaft rotates, a pushrod is moved up and down by that bump and the top of that rod operates the pump. This means there's no need for the stock pump to be located ON TOP of the engine. It could be anywhere around the case that would let the pushrod reach the camshaft. The pump mounts on a moveable plastic block (and there may be a bore inside the case to guide the pushrod -- I don't remember -- but it would be fairly easy to cut this out of a junk case). In this way, you could mount a stock VW pump to one side, allowing a normal cowling and reliable fuel pumping with just one backup electric pump. When I had to replace my fuel pump, my car had gone more than 100,000 miles. Mike Taglieri On Aug 17, 2016 1:35 PM, "Jeff Scott via KRnet" wrote: > Paul, > > That particular configuration has a bit of a safety issue. You always > want at least one of your pumps before the gascolator. Check out any low > wing carburated Piper. The fuel flow goes from Fuel Tank -> Electric Fuel > Pump -> Gascolator -> Mechanical Fuel Pump -> Carb. > > The reason why you want one fuel pump before the gascolator is that even > the smallest leak in the gascolator will draw air under suction from the > pumps and starve the engine for fuel. If you have a pump before the > gascolator, you can turn on that pump to restore fuel flow. You may only > have a small seep or drip at the gascolator under pressure, but that's > enough of an air leak under suction to starve the engine. This was a > really common problem with the GlassAir series of aircraft. They were > designed with the gascolator under suction for the mechanical pump and had > chronic problems with fuel starvation thanks to an O-ring seal that didn't > seat well in their gascolator. > > Ideally, the first pump should not have to suck fuel up hill, which > eliminates the same problem should there be an air seep at a fuel line > junction between the tank and the pump. But the gascolator can be a real > problem because it is disassembled and reassembled regularly, so it's easy > to have an air seep on occasion. > > -Jeff Scott > Los Alamos, NM > > > Here is a picture of my first layout of my duel facet fuel pump design. I > got it from flycorvair.com. I ended up with something diferant with the > same pumps. > https://flic.kr/p/AoAMfe > > Paul Visk Belleville IL 618 406 4705 > Sent on the new Sprint Network from my Samsung Galaxy S?4 > > > ___ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options >
KR> Facet pumps in series
Paul, That particular configuration has a bit of a safety issue. You always want at least one of your pumps before the gascolator. Check out any low wing carburated Piper. The fuel flow goes from Fuel Tank -> Electric Fuel Pump -> Gascolator -> Mechanical Fuel Pump -> Carb. The reason why you want one fuel pump before the gascolator is that even the smallest leak in the gascolator will draw air under suction from the pumps and starve the engine for fuel. If you have a pump before the gascolator, you can turn on that pump to restore fuel flow. You may only have a small seep or drip at the gascolator under pressure, but that's enough of an air leak under suction to starve the engine. This was a really common problem with the GlassAir series of aircraft. They were designed with the gascolator under suction for the mechanical pump and had chronic problems with fuel starvation thanks to an O-ring seal that didn't seat well in their gascolator. Ideally, the first pump should not have to suck fuel up hill, which eliminates the same problem should there be an air seep at a fuel line junction between the tank and the pump. But the gascolator can be a real problem because it is disassembled and reassembled regularly, so it's easy to have an air seep on occasion. -Jeff Scott Los Alamos, NM ? Here is a picture of my first layout of my duel facet fuel pump design. ?I got it from flycorvair.com. ?I ended up with something diferant with the same pumps. https://flic.kr/p/AoAMfe Paul Visk?Belleville IL ?618 406 4705 Sent on the new Sprint Network from my Samsung Galaxy S?4 ?
KR> Facet pumps in series
Larry said: ?With the discussion on fuel pumps I drew up a very simple diagram of?>my system. https://dl.dropboxusercontent.com/u/32133949/fuel%20system%20001.jpg Here is a picture of my first layout of my duel facet fuel pump design. ?I got it from flycorvair.com. ?I ended up with something diferant with the same pumps. https://flic.kr/p/AoAMfe Paul Visk?Belleville IL ?618 406 4705 Sent on the new Sprint Network from my Samsung Galaxy S?4 Original message From: Larry Flesner via KRnet List-Post: krnet@list.krnet.org Date: 08/16/2016 7:46 PM (GMT-06:00) To: KRnet Cc: Larry Flesner Subject: Re: KR> Facet pumps in series
KR> Facet pumps in series
> >With the discussion on fuel pumps I drew up a very simple diagram of >my system. https://dl.dropboxusercontent.com/u/32133949/fuel%20system%20001.jpg >Outer wing tanks 12.5 gallon each, no engine driven fuel pump, back >up battery system for electric pumps, both on for takeoff and >landing, alternate in cruise, 600+ hours with no problems >Larry Flesner >flesner at frontier.com ++ The fuel shutoff valves, tee, and pumps are all located under the cover on the forward face of the spar. Backup battery switches located on the red panel on bottom edge of instrument panel. Use once and it saved my bacon when I lost my main electrical buss. https://dl.dropboxusercontent.com/u/32133949/IMG_8717.JPG Larry Flesner flesner at frontier.com
KR> Facet pumps in series
With the discussion on fuel pumps I drew up a very simple diagram of my system. https://dl.dropboxusercontent.com/u/32133949/fuel%20system%20001.jpg Outer wing tanks 12.5 gallon each, no engine driven fuel pump, back up battery system for electric pumps, both on for takeoff and landing, alternate in cruise, 600+ hours with no problems Larry Flesner flesner at frontier.com
KR> Facet pumps in series
Here is a link to the diagram. http://n1160hminiplane.com/resources/_wsb_772x422_Miniplane+Fuelsys.JPG > On August 15, 2016 at 8:56 PM Craig Williams via KRnet list.krnet.org> > wrote: > > > Thanks for the help. Here is what I have installed. It took some pondering > to > find a workaround for the primer but I think I came up with a good system. > > Craig > > > > On August 13, 2016 at 7:04 PM Mark Langford wrote: > > > > > > Craig Williams wrote: > > > > > Can you plumb 2 facet pumps in series and will each run the engine > > > if the other fails? > > > > It may depend on exactly which model you buy, but I did exactly that > > with N56ML and N891JF, using the Facet 40108 that is commonly sold by > > AS and Wicks. See http://www.n56ml.com/fuel/ for more on that. The > > first photo down appears as though there's a "cross" in the system, but > > they are simply overlapping with a tie-wrap to secure the flex hose end. > ___ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options
KR> Facet pumps in series
Thanks for the help. Here is what I have installed. It took some pondering to find a workaround for the primer but I think I came up with a good system. Craig > On August 13, 2016 at 7:04 PM Mark Langford wrote: > > > Craig Williams wrote: > > > Can you plumb 2 facet pumps in series and will each run the engine > > if the other fails? > > It may depend on exactly which model you buy, but I did exactly that > with N56ML and N891JF, using the Facet 40108 that is commonly sold by > AS and Wicks. See http://www.n56ml.com/fuel/ for more on that. The > first photo down appears as though there's a "cross" in the system, but > they are simply overlapping with a tie-wrap to secure the flex hose end.
KR> Facet pumps in series
My KR-2 has a single Facet electric fuel pump in series with a mechanical pump on the 2180 VW. The Facet will will free flow fuel in the forward direction. The stock VW fuel pump has a shut off feature that will not free flow fuel if the engine is not running; the Facet cannot pump fuel through the non-running mechanical pump. I put a check valve in parallel with the VW mechanical pump to get fuel in the system, including the carburetor, for starting. The check valve also permits engine operation if the mechanical pump fails. Because I requested night VFR airworthiness , the FAA inspector required fuel flow measurements with each pump operating separately and the engine at WOT, max AOA and minimum fuel. Each test did require some discrete plumping changes firewall forward. Test fuel flows were 21 gallons per hour for the VW mechanical pump and 23 gallons per hour with the Facet. WOT and best power mixture at 13.6 AFR burns 5.3 gallons per hour. The Facet has a check valve built-in, the VW pump will not back flow and the extra check valve is not supposed to let fuel back flow; but after shut down the fuel in the system will drain back to the selected tank. The whole system, including the carburetor and gascolator, drains empty back to the fuel tank selected in about twenty minutes. How the carb float bowl and the gascolator empty is a mystery to me. If the fuel selector valve is set to off, the system will retain fuel. Sid Wood Tri-gear KR-2 N6242 Mechanicsville, MD, USA --- Question Can you plumb 2 facet pumps in series and will each run the engine if the other fails. I have been trying to plumb them in parallel but its a real pain to get the tubing all bent correctly. Series would be much easier. It looks like the Zenith 601 was doing it at one time. Not sure they still are. Thanks. Craig
KR> Facet pumps in series
At 05:52 PM 8/13/2016, you wrote: >Can you plumb 2 facet pumps in series and will each run the engine >if the other >fails. ++ Your question has pretty much been answered but I can confirm. I've run 2 pumps in series for 600+ hours with no engine driven pump. Both on for takeoff and landing and alternate use in the air. Do a simple ground test before installing to insure your pumps work the same way. Larry Flesner flesner at frontier.com
KR> Facet pumps in series
I feel really simple here kids. The KR2 Stock retractable gear that I am putting back together with advice from some you and local mechs has wet wings that I dont plan on using. Instead...A gravity feed slide valve carb with mixture control is as sophisticated as Im going to get but she will be strictly a VFR day flyer. Good to read you Sid. On Aug 14, 2016 7:42 PM, "Sid Wood via KRnet" wrote: > My KR-2 has a single Facet electric fuel pump in series with a mechanical > pump on the 2180 VW. The Facet will will free flow fuel in the forward > direction. The stock VW fuel pump has a shut off feature that will not > free flow fuel if the engine is not running; the Facet cannot pump fuel > through the non-running mechanical pump. I put a check valve in parallel > with the VW mechanical pump to get fuel in the system, including the > carburetor, for starting. The check valve also permits engine operation if > the mechanical pump fails. Because I requested night VFR airworthiness , > the FAA inspector required fuel flow measurements with each pump operating > separately and the engine at WOT, max AOA and minimum fuel. Each test did > require some discrete plumping changes firewall forward. Test fuel flows > were 21 gallons per hour for the VW mechanical pump and 23 gallons per hour > with the Facet. WOT and best power mixture at 13.6 AFR burns 5.3 gallons > per hour. > The Facet has a check valve built-in, the VW pump will not back flow and > the extra check valve is not supposed to let fuel back flow; but after shut > down the fuel in the system will drain back to the selected tank. The > whole system, including the carburetor and gascolator, drains empty back to > the fuel tank selected in about twenty minutes. How the carb float bowl > and the gascolator empty is a mystery to me. If the fuel selector valve is > set to off, the system will retain fuel. > > Sid Wood > Tri-gear KR-2 N6242 > Mechanicsville, MD, USA > > --- > Question > > Can you plumb 2 facet pumps in series and will each run the engine if the > other > fails. I have been trying to plumb them in parallel but its a real pain to > get > the tubing all bent correctly. Series would be much easier. It looks like > the Zenith 601 was doing it at one time. Not sure they still are. > > Thanks. > Craig > > > > > ___ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options >
KR> Facet pumps in series
Facet Pumps in series If you are buying these pumps from another source, say a racing shop or something, you have to watch the model you buy. Facet implements 2 feature options that will prevent them from being used in series. Most of their pumps have check valves in them that ensures fuel moves only one direction. That's not a problem for us generally. The other feature is the positive shut off integral to some models. In these models, if the pump is off you can not push or pull fuel through themI will point you to their web site for a matrixthe PSO column indicates the presence of the Positive Shut Off... http://www.facet-purolator.com/cube-fuel-pumps.php Phill Hill Collinsville, IL
KR> Facet pumps in series
Sorry, forgot the link http://krbuilder.org/FirewallForward/FuelSystem/FuelPumpTests/index.html See N64KR at <http://krbuilder.org/> http://KRBuilder.org - Then click on the pics 2016 KR Gathering - Mt. Vernon, Ill. Peoples Choice at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best KR at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Interior at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Paint at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Firwwall Forward at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Interior and Panel at 2008 - KR Gathering in Mt. Vernon, Il - MVN Daniel R. Heath - Lexington, SC -Original Message- From: KRnet [mailto:krnet-bounces at list.krnet.org] On Behalf Of Craig Williams via KRnet Sent: Saturday, August 13, 2016 6:52 PM To: KRnet Cc: Craig Williams Subject: KR> Facet pumps in series Question Can you plumb 2 facet pumps in series and will each run the engine if the other fails. I have been trying to plumb them in parallel but its a real pain to get the tubing all bent correctly. Series would be much easier. It looks like the Zenith 601 was doing it at one time. Not sure they still are. Thanks. Craig <http://www.kr2seafury.com> www.kr2seafury.com <http://www.N1160Hminiplane.com> www.N1160Hminiplane.com ___ Search the KRnet Archives at <http://tugantek.com/archmailv2-kr/search> http://tugantek.com/archmailv2-kr/search. To UNsubscribe from KRnet, send a message to <mailto:KRnet-leave at list.krnet.org> KRnet-leave at list.krnet.org please see other KRnet info at <http://www.krnet.org/info.html> http://www.krnet.org/info.html see <http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org> http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options
KR> Facet pumps in series
This was a discussion a good many years ago, so I documented some tests to prove that you can install them in series. In fact, that is how they were installed on the Black Bird. See N64KR at <http://krbuilder.org/> http://KRBuilder.org - Then click on the pics 2016 KR Gathering - Mt. Vernon, Ill. Peoples Choice at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best KR at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Interior at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Paint at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Firwwall Forward at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Interior and Panel at 2008 - KR Gathering in Mt. Vernon, Il - MVN Daniel R. Heath - Lexington, SC -Original Message- From: KRnet [mailto:krnet-bounces at list.krnet.org] On Behalf Of Craig Williams via KRnet Sent: Saturday, August 13, 2016 6:52 PM To: KRnet Cc: Craig Williams Subject: KR> Facet pumps in series Question Can you plumb 2 facet pumps in series and will each run the engine if the other fails. I have been trying to plumb them in parallel but its a real pain to get the tubing all bent correctly. Series would be much easier. It looks like the Zenith 601 was doing it at one time. Not sure they still are. Thanks. Craig <http://www.kr2seafury.com> www.kr2seafury.com <http://www.N1160Hminiplane.com> www.N1160Hminiplane.com ___ Search the KRnet Archives at <http://tugantek.com/archmailv2-kr/search> http://tugantek.com/archmailv2-kr/search. To UNsubscribe from KRnet, send a message to <mailto:KRnet-leave at list.krnet.org> KRnet-leave at list.krnet.org please see other KRnet info at <http://www.krnet.org/info.html> http://www.krnet.org/info.html see <http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org> http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options
KR> Facet pumps in series
Question Can you plumb 2 facet pumps in series and will each run the engine if the other fails. I have been trying to plumb them in parallel but its a real pain to get the tubing all bent correctly. Series would be much easier. It looks like the Zenith 601 was doing it at one time. Not sure they still are. Thanks. Craig www.kr2seafury.com www.N1160Hminiplane.com
KR> Facet pumps in series
Craig Williams wrote: > Can you plumb 2 facet pumps in series and will each run the engine > if the other fails? It may depend on exactly which model you buy, but I did exactly that with N56ML and N891JF, using the Facet 40108 that is commonly sold by AS and Wicks. See http://www.n56ml.com/fuel/ for more on that. The first photo down appears as though there's a "cross" in the system, but they are simply overlapping with a tie-wrap to secure the flex hose end. I get a slight fuel pressure boost on N56ML with both pumps running, but I keep the same pressure regardless on N891JF by using a pressure regulator inline that maintains 3 psi. Mark Langford ML at N56ML.com http://www.n56ml.com
