KR> Fuel pumps
> "In that flow test, you want to run the fuel through the carb and measure the flow rate coming out the drain plug of the carb." Wouldn't one want a pressure regulator somewhere between the fuel pump and the carb? Maybe the carbs you're referring to have one built in to them, such as a float valve. If the float ever degrades however, a pressure regulator might be a good thing to have. My Ellison requires an external regulator ahead of the carb inlet. Re fuel pumps, I've got a Facet for transferring fuel from wing tank to header like Jeff is mentioning, and I've got two fuel pumps (primary and a back-up on separate switch) between the header and my top mounted Ellison. They're the round ones that look like fuel filters. In all these years none of these pumps have ever failed. I turned my pump off one day in level cruise with fuel tank level well below the level of the Ellison. The engine continued to run just fine using siphon effect. I didn't test it with a climb or descent. It's good to know the engine will continue to run without the pump but it's always on anyway. An electric fuel pump is not something I would leave out of the fuel system . . . why would you consider it? To avoid having to use a pressure regulator? Not criticising, just wondering. I don't know enough about your carb and fuel system to say anything helpful. Mike KSEE Drink 1 Cup Before Bed, Watch Your Body Fat Melt Like Crazy mayserve-magestor.com http://thirdpartyoffers.juno.com/TGL3141/5cc79bf6102531bf57114st04vuc ___ Search the KRnet Archives at https://www.mail-archive.com/krnet@list.krnet.org/. Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options. To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org
KR> Fuel pumps
Larry said: I'm convinced that's what smoked it. Please take note; this IS GOOD INFO FOR ALL FUEL PUMPS ELECTRIC! Typically they are COOLED by the fuel that passes through them while they are running. I have seen countless bulletins sent to auto technicians warning running tanks dry during trouble shooting and warning to educate consumers if they think that they have POSSIBLY run out of gas, get some before continuing to try to crank the vehicle because as long as the computer "sees" rpms it will energize the pump to run even with no gas (no sensor there). Externals will dissipate the heat a little bit better but will still die... Colin Rainey brokerpi...@bellsouth.net
KR> Fuel Pumps
Phillip asked about fuel pumps running from crankcase pulsations. I am flying a Renegade with a Rotax 582 two-cycle engine. It has a pulse powered fuel pump mounted on the firewall. That engine burns 5 1/2 gallons per hour at cruise, so the output of the pump would be more than adequate for a KR. The hose connecting the crankcase to the pump must be fairly rigid--rubber hose or ordinary urethane tubing will dampen the pulses. I would assume that the crankcase pulses in a four or six cylinder engine at 3600 rpm would not be too far off the pulses in a two cylinder at 6600 rpm. Any Rotax dealer should be able to provide you a pump for around US $30. Jim Vance va...@claflinwildcats.com
KR>Fuel pumps
Netters, ON auto applications where there is multi-point fuel injection the fuel IS constantly re-circulated back to the tank, through a return line that is BELOW the fuel pickup for the fuel pump. The pump is only immersed in fuel completely at high levels and is cooled by gas flowing through it, hence the need for constant circulation. It also provides alot more fuel volume and pressure, so that at high demands the pressure regulator, also a part of ALL late model systems, will close and boost the normal line pressure up from 30-45 psi upwards of 50-65 psi, for the period of acceleration. This makes it possible for the fuel injection system to replace the mechanical carb part known as a power valve, which opens to supplement the fuel required only during acceleration. The pump is located in the tank to allow it to push the entire time not pull. Even the earlier TBI injection systems re-circulated fuel just at a lower pressure. Warnings to relieve pressure are for safety due to the high line pressure maintained for normal operation. IF this type of system is to be used on a KR the entire operating system must be duplicated or you will be going way out on a limb designing your own version. Colin & Bev Rainey KR2(td) N96TA Sanford, FL crain...@cfl.rr.com or crbrn9...@hotmail.com http://kr-builder.org/Colin/index.html
KR>Fuel pumps / regulators
With all the problems with these things it is hard not to believe we are trying to reinvent the wheel again. Motorcyle carbs like the mikuni and zenith are intended for gravity feed but some bike designs with their gas tank shapes do not feed well that way. So some have small electric fuel pumps with built in regulators. My kawasaki classic is one of them. You know what I will be trying. Used or rebuilts go for around $50. I will need a pair to have redundancy with my wing tanks, as I want no header tank. Though I suppose simplicity would be a half gallon header with overflows back to the wings with simple inexpensive auto pumps that run constantly. Steve McGee Endeavor Wi. USA Building a KR2S widened. lmc...@maqs.net
KR>Fuel pumps/ wing tanks(long)
Much as Scott said, while not located near a tank for "pushing" >it is located at the lowest point in the system prior to it's upward bend to >the enginethus pushing. >Dana Overall + While not claiming my system is the way to go I'll tell you what works for me and is now flight proven with (only) two hours of flight. I have a 12 1/2 gal tank in each outer wing panel and no header tank. I have two Facet pumps that are plumbed in parallel. I have a fuel line from each tank to a shutoff valve located on the front face of the forward spar just below my knees. Between the shutoff valves is a tee that takes a single line to the two pumps (in parallel) and from there to the firewall gascolator and on to the carb. The fuel pressure gauge is in line just past the pumps. Between that fitting and the firewall is my fuel pressure regulator. This setup allows me to use either/both pumps to pump from either/both tanks and check either/both pumps with a single pressure gauge. My standard proceedure is to fly with both tanks turned on using a single pump except for takeoff and landing. Each pump has a separate switch and indicator light for "on". Because I would go into "glide" mode soon after having to turn off my electrical system I installed a backup power source for the pumps. A small motorcycle battery on the firewall feeds a separate buss and uses separate circuit brakers and switches to the pumps. The only thing in common is the pumps and the wires leading to the instrument panel. The circuits are isolated using diodes so I don't get feedback from the main to backup buss. If I have to shut down my electrical system in flight I simply turn off the fuel pump switch of the operating pump and flip a single switch to bring a pump back on line with the backup battery. A switch next to my volt meter on the panel allows me to monitor the condition of my backup battery, "up" for aux battery, "down" for main battery. Checking the condition of the backup battery and exercising the pumps on the backup system is one of the first items on my checklist before engine startup. One of the drawbacks of this system is that it requires a high number of flare fittings and thus a greater chance for leaks. I had several concerns about such a system while designing it. 1. Would the pumps be able to prime the line and draw fuel being being located that far from the tanks. I tested the pumps using water (heavier than gas) and was able to draw at a height of 30 inches. Early taxi test in the yard using a fuel can suspended from and below the wing attach fittings indicated that was not a problem. 2. Would the pumps, in parallel, simply form a loop in the system and pump fuel in a circle through the pumps without a check valve on each pump. I plumbed the pumps "head to head" and could not pump fuel "backward" through the pump. I eliminated the check valves. 3. Would the pickup in the wings "unport" in flight causing the pumps to suck air. I concluded that if both tanks were turned "on" that one tank or the other should always have fuel at the fuel pickup during any given flight mode. The unported pickup should have fuel flowing through the line from the pickup that has fuel, it being at that moment the higher of the two. My early flights had approx 5 gal in each tank and with approx two hours of flight time I have yet to see a problem. Even if both tanks unport at the same time, and I'm not sure how I'd get that to happen, I still have the fuel in the carb to keep the engine running for a short period. In several hours of running before attaching the wings, several hours of taxi test, and approx two hours of flight time, the engine has not so much as "burped" once. As always, your results may vary. Whatever system you use you must do a fuel flow test to insure you have sufficent flow in all flight attitudes. Do these test on the ground, not in the air! There is no "one perfect setup". Just make sure you consider all the possible failure modes for whatever system you have installed. Larry Flesner Carterville, Illinois www.krgathering.org
KR>Fuel pumps
Hi, I just thought someone might benefit from this- The fuel pump used on 1000cc and 1100cc Yamaha Virago motorcycles might be just what you need on a system with float bowl carbs. They are one piece, self contained with a pressure sensing diaphragm built in. When the pressure required by the carb is reached the diaphragm opens a set of points in the end of the pump and disconnects the 12 volt power from it until the pressure drops again and then closes the points so the pump runs again. The fuel pressure needed by a particular carb would be automatically controlled. The pump would put out until the needle closes against the seat and then stop until it unseats again. It would also stop a steady drain on the battery. It may be worth trying. All that's needed is a 12 volt connection and an in and out fuel line. Rick Wilson. = Rick Wilson, Haleyville, Alabama KR2-0200A -99% rwdw2...@yahoo.com __ Do you Yahoo!? Free Pop-Up Blocker - Get it now http://companion.yahoo.com/
KR>Fuel pumps/pressure regulator
For those needing to control the pressure of fuel pumps to a low pressure carb check out the fuel pressure regulator at Auto Zone. $20 and is adjustable from 1/2 to 5 1/2 pounds approx. I have one on my KR and I believe it is the same type used by Marty Roberts. My hangar neighbor has a Zenair 601 with a balanced Harley engine and his fuel pump was causing his carb to overflow. He installed this unit and kept dialing it down in pressure until the carb quit overflowing. The setting ended up to be 1.5 pounds. The unit is adjustable in 1/2 pound settings. Larry Flesner Carterville, Illinois
KR>Fuel pumps/pressure regulator
I used a similar device and found that at wide open throttle the fuel flow was not suffient and caused a lean condition at the highest rpm N110LR 19 years in a KR Orma
KR>Fuel pumps/pressure regulator
Orma, I am a newbee trying to determine if the KR would be a good choice kit for a large person (6'4",230 lbs) and does it take forever to build? Would appreciate any info? Thanks, JD -Original Message- From: aviationm...@aol.com [mailto:aviationm...@aol.com] Sent: Friday, December 05, 2003 6:16 AM To: kr...@mylist.net Subject: Re: KR>Fuel pumps/pressure regulator I used a similar device and found that at wide open throttle the fuel flow was not suffient and caused a lean condition at the highest rpm N110LR 19 years in a KR Orma ___ see KRnet list details at http://www.krnet.org/instructions.html
KR>Fuel pumps/pressure regulator
Larry, DO you have a part number or SKU. At AutoZone, they can't do anything without a vehicle application, SKU or Part Number. --- larry flesner wrote: > For those needing to control the pressure of fuel > pumps to a low pressure carb check out the fuel pressure regulator at Auto Zone. $20 and is adjustable from 1/2 to 5 1/2 pounds approx. I have one on my KR and I believe it is the same type used by Marty Roberts. = Scott Cable KR-2S # 735 Wright City, MO s2cab...@yahoo.com __ Do you Yahoo!? Free Pop-Up Blocker - Get it now http://companion.yahoo.com/
