---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Thu 05/11/06: 9 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:01 AM - Re: Redundancy.. ITm not gonna repeat myself ! (pat ladd) 2. 02:27 AM - Re: Redundancy (Dave Bigelow) 3. 03:41 AM - redundancy (Edward Steuber) 4. 05:24 AM - Re: Re: Redundancy (Richard Pike) 5. 09:07 AM - Re: Re: Redundancy (Richard & Martha Neilsen) 6. 09:48 AM - Magnetic error (David Paule) 7. 09:48 AM - Re: Re: Redundancy (robert bean) 8. 01:15 PM - Re: Redundancy (Kirby Dennis Contr MDA/AL) 9. 02:31 PM - Re: Re: Redundancy (John Hauck) ________________________________ Message 1 _____________________________________ Time: 02:01:13 AM PST US From: "pat ladd" Subject: Re: Kolb-List: Redundancy.. ITm not gonna repeat myself ! --> Kolb-List message posted by: "pat ladd" here in yank land we like excess>> Hi Ralph, I think it comes from having far more than your fair share of the worlds resources. Wasting things is a national pastime. I well remember on my first visit the the USA, around the early `70s, coming across `Turf and Surf` on a menu. I was horrified that with half the world starving anyone could come up with a culinary experiment that was not only supremely wasteful but spoiled both the lobster and the steak. There is no doubt that King George made a wrong decision by allowing you to keep America. We did the same with France. If we had hung on to it what a great country it would be now. After all the only thing wrong with France is that it is full of French. Cheers Pat do not archive -- Version: 7.1.392 / Virus Database: 268.5.5/335 - Release Date: 09/05/2006 ________________________________ Message 2 _____________________________________ Time: 02:27:46 AM PST US Subject: Kolb-List: Re: Redundancy From: "Dave Bigelow" --> Kolb-List message posted by: "Dave Bigelow" Dennis, The electric pump redundancy is a good idea. If you look at the specs for the Mikuni engine pumps that come with the two stroke Rotax engines, you'll see that they are rated to lift fuel no more than about 36 inches. Measure the distance to the mid point of your fuel tanks and you'll see that it is pretty close to that. I've believed for some time that some of the mysterious engine seizures that seem to happen for no known reason are partial fuel starvation caused by the pulse pump not putting out enough fuel. The classic failure is a full power take off and climb, followed by a seizure when the power is pulled back. The electric pump should be plumbed in parallel rather than in series. Both the mechanical and electric pumps have a built in check valve, so you don't need to add check valves unless you want more redundancy. If you plumb the pumps in series, the fuel pressure will be too high (unless you install a regulator), and either pump failing can block the single fuel path to the engine. There was a good article in "Ultralight Flying" several years ago by Arnold Anderson (Fight Safety Notebook) on the subject. I don't see any reason to turn the electric pump off in flight unless you don't have battery charging, and want to save electricity. -------- Dave Bigelow Kamuela, Hawaii FS2, Rotax 503 DCDI Read this topic online here: http://forums.matronics.com/viewtopic.php?p=33990#33990 ________________________________ Message 3 _____________________________________ Time: 03:41:42 AM PST US From: "Edward Steuber" Subject: Kolb-List: redundancy --> Kolb-List message posted by: "Edward Steuber" You guys are making my head hurt from all this complication , I'm with = BB on the simplistic side of the issue....The reason I got into = ultralights was the shear joy of uncomplicated flight....also .... I = tend to be a bit cheap so buying 2 of everything is not an option = anyway... Ed in Western NY do not archive ________________________________ Message 4 _____________________________________ Time: 05:24:07 AM PST US From: Richard Pike Subject: Re: Kolb-List: Re: Redundancy --> Kolb-List message posted by: Richard Pike I disagree that the pressure would be too high. I have a fuel pressure gauge on the panel, my pumps are in series, and I learned that with both pumps working, the fuel pressure pickup located between the Mikuni and carbs, the pressure is 3 1/2 pounds. I relocated the pickup for the pressure gauge, so that it now only monitors the Facet electric pump. Still shows 3 1/2 pounds. Left the pressure pickup at that location. I test the Mikuni during taxi out and run up by turning the electric pump off, (fuel pressure gauge falls to zero) engine still runs ok, Mikuni must be working, and drawing fuel through the Facet. Then I turn the electric pump back on for the rest of the flight. Should the Mikuni fail in flight, as long as the pressure is showing 3 pounds or better, I know I will get fuel, because I see no way for the Mikuni to block the fuel that the electric pump is pushing into the inlet side. Don't know about the article in Ultralight Flying, but I know what works. It might get blocked up tomorrow, but it's worked fine since '98. Richard Pike MKIII N420P (420ldPoops) Dave Bigelow wrote: > --> Kolb-List message posted by: "Dave Bigelow" > > Dennis, > > The electric pump redundancy is a good idea. If you look at the specs for the Mikuni engine pumps that come with the two stroke Rotax engines, you'll see that they are rated to lift fuel no more than about 36 inches. Measure the distance to the mid point of your fuel tanks and you'll see that it is pretty close to that. > > I've believed for some time that some of the mysterious engine seizures that seem to happen for no known reason are partial fuel starvation caused by the pulse pump not putting out enough fuel. The classic failure is a full power take off and climb, followed by a seizure when the power is pulled back. > > The electric pump should be plumbed in parallel rather than in series. Both the mechanical and electric pumps have a built in check valve, so you don't need to add check valves unless you want more redundancy. If you plumb the pumps in series, the fuel pressure will be too high (unless you install a regulator), and either pump failing can block the single fuel path to the engine. There was a good article in "Ultralight Flying" several years ago by Arnold Anderson (Fight Safety Notebook) on the subject. > > I don't see any reason to turn the electric pump off in flight unless you don't have battery charging, and want to save electricity. > > -------- > Dave Bigelow > Kamuela, Hawaii > FS2, Rotax 503 DCDI > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=33990#33990 > > > > > > > > ________________________________ Message 5 _____________________________________ Time: 09:07:09 AM PST US From: "Richard & Martha Neilsen" Subject: Re: Kolb-List: Re: Redundancy --> Kolb-List message posted by: "Richard & Martha Neilsen" I have two electric fuel pumps plumed into my fuel system in series. I would prefer one of my fuel pumps to be some thing other than electric but my reduction drive sits were the mechanical fuel would be. I use a Facet as one of my pumps. I would never want to depend on a Facet pump because I have experienced a few failures with them. I use the following procedure that tests both pumps before each flight. I prime my carbs by turning on only the Facet pump which is the first in series and is my backup or boost pump. I can physically see the flow rate as I have a short piece of transparent fuel line just before the carbs. then I turn it off. I then start the engine using only the primary pump and continue thru warm-up and run up. Just before take off I switch on the Facet pump. After takeoff I turn the Facet pump off. I don't like to run both pumps all the time because I feel that I might be wearing out both pumps and want to have at least one fairly unused pump there for back up if my primary pump fails. This is also the same procedure I was trained to use and described in the Piper Owners Manual. There must have been reason Piper Aircraft suggested turning off the boost pump at altitude so I follow the same guideline with my Kolb. Rick Neilsen Redrive VW powered MKIIIc ----- Original Message ----- From: "Dave Bigelow" Sent: Thursday, May 11, 2006 5:27 AM Subject: Kolb-List: Re: Redundancy > --> Kolb-List message posted by: "Dave Bigelow" > > Dennis, > > The electric pump redundancy is a good idea. ________________________________ Message 6 _____________________________________ Time: 09:48:25 AM PST US From: "David Paule" Subject: Kolb-List: Magnetic error --> Kolb-List message posted by: "David Paule" FYI, alkaline batteries are quite magnetic and, if placed close to your compass, can cause a deviation. Found this out on the Skywagon some time ago, with extra batteries in the glove box, at least a foot and a half from the compass. I generally use Duracells, for which this warning applies, haven't tried others. Dave Paule Boulder ________________________________ Message 7 _____________________________________ Time: 09:48:25 AM PST US From: robert bean Subject: Re: Kolb-List: Re: Redundancy --> Kolb-List message posted by: robert bean Easy to tell when the Facet is ready. -Turn on the ignition and wait until the tone changes and its ready to hit start. For the person who wanted the low pressure number: 40105 AC Spruce has them in stock -BB On 11, May 2006, at 12:00 PM, Richard & Martha Neilsen wrote: > --> Kolb-List message posted by: "Richard & Martha Neilsen" > > > I have two electric fuel pumps plumed into my fuel system in series. I > would > prefer one of my fuel pumps to be some thing other than electric but my > reduction drive sits were the mechanical fuel would be. I use a Facet > as one > of my pumps. I would never want to depend on a Facet pump because I > have > experienced a few failures with them. > > I use the following procedure that tests both pumps before each > flight. I > prime my carbs by turning on only the Facet pump which is the first in > series and is my backup or boost pump. I can physically see the flow > rate as > I have a short piece of transparent fuel line just before the carbs. > then I > turn it off. I then start the engine using only the primary pump and > continue thru warm-up and run up. Just before take off I switch on the > Facet > pump. After takeoff I turn the Facet pump off. > > I don't like to run both pumps all the time because I feel that I > might be > wearing out both pumps and want to have at least one fairly unused pump > there for back up if my primary pump fails. This is also the same > procedure > I was trained to use and described in the Piper Owners Manual. There > must > have been reason Piper Aircraft suggested turning off the boost pump at > altitude so I follow the same guideline with my Kolb. > > Rick Neilsen > Redrive VW powered MKIIIc > > > ----- Original Message ----- > From: "Dave Bigelow" > To: > Sent: Thursday, May 11, 2006 5:27 AM > Subject: Kolb-List: Re: Redundancy > > >> --> Kolb-List message posted by: "Dave Bigelow" >> >> >> Dennis, >> >> The electric pump redundancy is a good idea. > > ________________________________ Message 8 _____________________________________ Time: 01:15:53 PM PST US From: Kirby Dennis Contr MDA/AL Subject: Kolb-List: Re: Redundancy --> Kolb-List message posted by: Kirby Dennis Contr MDA/AL << do you mount the electric pump close to the fuel tank (gulp..sparks), or is it mounted up along the frame of the cage so that you can see it? ralph of Ohio >> Ralph - Using a pair of aluminum brackets spanning between two of the cage members on the fuselage side, I fashioned a method to attach the Facet level with the bottom of the fuel tanks and angled at 45 degrees (per fuel pump installation instructions). Part of my preflight is to peer behind the seat to inspect the pump, mostly for security of hose connections. Easy to see and service (if needed). << Next, which model number pump is it and is it in the low (3 psi) range as previously described by others in order to not overcome the float bowles? >> >From the ACSpruce catalog, I purchased the Facet model 40105, 2.5 to 4.5 psi max, 12v, solid state pump. As it is solid state (not an electric motor), there is no worry about sparks. The Rotax manuals warn that pressures above 5.8 psi may lead to "override of float valves," but there is some protection in the float bowl overflow feature. The overflow can handle pressures up to perhaps 7 or 8 psi before the floats become overwhelmed with too much incoming fuel. I have never yet seen the carb bowls overflow on my Bings from the Facet pump being left on (while the engine is running). You are wise to follow the "keep it simple" advice from the List members that offer it, with regard to fuel systems. Dennis Kirby Mark-III, 912ul, in Cedar Crest, NM ________________________________ Message 9 _____________________________________ Time: 02:31:26 PM PST US From: "John Hauck" Subject: Re: Kolb-List: Re: Redundancy --> Kolb-List message posted by: "John Hauck" "override of | float valves," but there is some protection in the float bowl overflow | feature. The overflow can handle pressures up to perhaps 7 or 8 psi before | the floats become overwhelmed with too much incoming fuel. | | Dennis Kirby | Mark-III, 912ul, in | Cedar Crest, NM Dennis: That outlet on the float bowl chamber of the 912 carb is not an overflow as I thought when I initially installed the 912 on my mkIII in 1994. That is one of the static air sources that works with the other static air source in the lip of the carb inlet. These two static sources and the position of the throttle plate tell the piston in the carb where it should be positioned. That is why it is important for them to all read the same static pressure. The low pressure Facet and the engine driven pump will not produce enough pressure to override the floats and needles. This is covered in the Rotax 912 School presented by Eric Tucker. After three classes over the last six years I think I have that part down correctly. hehehe john h mkIII