uk_figs

uk_figs

Well Known Member
Friend
Just getting to the stage of piping the fuselage fuel lines from the fuel valve to the fuel pump on my 7. Planning a 0-360 and have been reading the threads on the standard facet fuel pump from Van's (just about to order). If I decided to go for the cannister aviation type (from Aircraft Spruce) which model do I need? What fuel pressure and gph would be required.

Thanks
 
The little Facet is just fine along with the Van's gascolator. That will keep things simple. I assume you are using an engine driven mechanical pump as well.

Roberta
 
Roberta
Thanks, I decided to stick with the Van's simple approach as you suggest and ordered the standard Facet pump.
 
:/

I don't really like the little box one... and have been kinda vocal about it. They work fine until they fail I guess.
 
I'm still running the original Facet pump on my -6 (14 years now). Never missed a beat.
 
Mine has been running for over 9 years and 1,973 hours with no problems. There is one RV-6A in SoCAL that that just pulled the engine for overhaul with 2,500 hours that has also never had any problem with the electric boost pump that Van Recommends.
 
Been running these on cars for 25+ years and never seen one fail if mounted correctly. They are designed to be mounted at an angle. Very reliable in my experience.
 
facet pump

osxuser said:
... They work fine until they fail I guess.
Click to expand...
Can't really argue with the statement :) , it works for everything. What's your actual experience? 1 hour, 10, 10000 hr time to failure?

thanks,
-mike
 
Little box fuel pumps

I (we) run the same ones on our irrigation engines and they do fail after a while. I would guess in about five to six years pumping 24 hours a day for about 90 days a year, around 2500 - 3000 gallons a year. That being said your engine driven fuel pump should do the job untill you replace the little box.
Just my 2 bits
The Double Eagle (RV9-A)
 
Harvey L. Sorensen said:
I (we) run the same ones on our irrigation engines and they do fail after a while. I would guess in about five to six years pumping 24 hours a day for about 90 days a year, around 2500 - 3000 gallons a year. That being said your engine driven fuel pump should do the job untill you replace the little box.
Just my 2 bits
The Double Eagle (RV9-A)
Click to expand...
90 days x 24 hours x 5 years = 10,800 hours. I can live with that. ;)
 
mlw450802 said:
Can't really argue with the statement :) , it works for everything. What's your actual experience? 1 hour, 10, 10000 hr time to failure?

thanks,
-mike
Click to expand...
It wasn't the time it failed in... (Which I'm not positive on, it was a customer's rv-6). It was the mode of failure... partially blocking the fuel supply and making the engine loose partial power on upwind. I'll stick with the canister. I know plenty of people have no problem with the 'box', but the big canister seems like cheap insurance to me. In 35 years, and 1800+ hours on a Cardinal with no problem. I've never seen a canister type fail in the last 5 years I've been doing GA maintanence, don't know if that means anything.
 
I have been biting my tongue on this one so far because I do not want to second guess Van's engineering for wich I have great respect but after the last post regarding the failure mode I feel compelled to relate my experience.

My RV6 was built according to plans with the square Facet pump plumbed as recommended. Several years ago after flying over a 1000hrs with no problems I had an engine failure after take-off at about 500' AGL. When I lowered the nose and played with the throttle I got partial power back and was able to land on the airport. I had just refueled on a hot Texas afternoon and suspected vapour lock because subsequent full power run-ups showed no problem. Then the same scenario occured again six month later in cold weather on initial take-off in the morning. Like before, some power came back when I lowered the nose and pulled back the throttle. This time I grounded the bird until a culprit was found. Suspecting the Facet pump I bought another one at the auto supply store. Before installing it I disected the old one and was amazed at how miniscule the flow thru area is. That was also the root of my problem as a very small piece of trash had lodged in the orifice, mostly blocking the flow. As it turned out there was no malfunction of the pump itself but the way the fuel system works that small piece of trash could have been fatal. With this design all fuel to the engine must flow thru this small orifice in the pump and there is no screen upstream of the pump. The gascolator is further down stream and the saw slits in the pick-up tubes allow fairly large debris to enter the system. By the way, the instruction sheet enclosed with the pump I bought from the parts store stipulated that a screen or filter must be installed ahead of the pump.

Based on my findings I chose to copy the fuel delivery system of my PA 28-140. It has the beer can type Facet pump installed AFTER the gascolator. In addition, this pump has it's own built-in screen to keep trash out of the works and is plumbed parallel to the engine driven pump so neither pump has to draw it's fuel thru the other one. Now I see much more consistent fuel pressure even at altitude and in high power climb even with the boost pump off. Unfortunately a friend of mine crashed his RV6 (no injuries) because of the same problem.

I have flown my 6 over another 1000hrs since with no further fuel delivery problems. I am not avocating changing Van's design but just explaining what happened in my case. However if you have the intake tubes with saw cuts or worse, tanks with slosh, making sure that little pump stays free of debris might be a wise move.

Martin Sutter
building and flying RV's since 1988
 
Where did you mount the pump?

Martin Sutter said:
Based on my findings I chose to copy the fuel delivery system of my PA 28-140. It has the beer can type Facet pump installed AFTER the gascolator. In addition, this pump has it's own built-in screen to keep trash out of the works and is plumbed parallel to the engine driven pump so neither pump has to draw it's fuel thru the other one. Now I see much more consistent fuel pressure even at altitude and in high power climb even with the boost pump off. Unfortunately a friend of mine crashed his RV6 (no injuries) because of the same problem.


Martin Sutter
building and flying RV's since 1988
Click to expand...

Martin,
Did you mount the beer can type pump on the engine side of the firewall?
Does this parallel plumbing have any check valves?
If both the engine driven pump and the beer can Facet pump have internal check valves, this would seem to be a safe system.

I like the idea of the parallel plumbing, but if either pump had a failure that allowed fuel to backfeed through it you could just be pumping fuel in a circle.
And if this happens the carb may not get enough.

Thoughts anyone?

Mark
 
Last edited:
Martin mentioned the "small" orifice in the Facet pump. If you are really concerned about this, take a look into the fuel flow transducer. It is smaller yet. That's why I recommend a filter either just before or just after the selector valve. I have 2 filters on my -6 just before the selector.
 
The pump is mounted on the engine side of the fire wall at the lower left. Both the engine driven pump and the electric have dual check valves in them. Both pumps have air blast tubes on them. The set up is an excact copy of the Piper Pa 28-140 installation, same part number electric and engine driven pump. This configuration has proven itself over 40 years of operation in Cherokees. Yes, the passage in the fuel flow transducer is small but the passage in the square Facet pump is even smaller! In addition to that, fuel is pushed thru the transducer in most installations while it has to be drawn (pushed by ambient pressure) thru the Facet pump.

Martin
 
Mel said:
Martin mentioned the "small" orifice in the Facet pump. If you are really concerned about this, take a look into the fuel flow transducer. It is smaller yet. That's why I recommend a filter either just before or just after the selector valve. I have 2 filters on my -6 just before the selector.
Click to expand...
Mel. What brand/type of filters have you used?

Fin.
 
The filters I have, (one for each tank) just ahead of the selector valve are from Aircraft Spruce p/n 806. Page 164 in the current catalog.
 
It doesn't sound like the pumps fail but it does sound like the introduction of "debris" in the fuel tank is, as always, a bad idea. Wonder if the purported fuel starvation aircraft had a screen on the fuel pick up inside the tank?

Kind of curious to read the NTSB final report that found the "pump" or fuel blockage in the pump as the "cause" of a crash? What N number was the plane?
 
Remember, if you install filters ahead of the selector, you must have some way of turning off the fuel supply to service the filters.
 
Remember, if you install filters ahead of the selector, you must have some way of turning off the fuel supply to service the filters.
Click to expand...

And if you use filters be sure they can not be clogged by water.

I purchased filters to replace my gascolater but chickened out after pondering why I would want to mess with a fuel system that has been flawless for ~800 hrs.....
 
Be carefull with FACET pump!

Greetings form Mexico.

The last sunday on the second fly of day, my FACET pump didn't work!, but my primary pump work perfectly, I thought not problem my primary fuel system is ok, later I flew over the airport for 15 minute more, no problems on board. The monday I removed the FACET pump, I expect any electrical problem with it, but my blood was at my ankles, Litle piece of dirt block the pump, TREMENDOUS MY ERROR AT FLY WITH FAIL ON THE FUEL SYSTEM, please take your FACET pump and inspect it, looking for dirt or any corrosion signal.

I'm looking was is it the best way to perfect the original fuel system.

Thanks a lot and excuse me my bad English.
 
Fuel Check Valve....

A local builder is plumbing a Fuel check valve in parallel to the facet pump. So if partial or complete blockage happens at the facet pump due to debris or mechanical breakdown, the fuel can still flow thru the ckeck valve....This appears to me as a good safety feature.
Anyone of you have seen or experiment that solution ?
I'll be plumbing my fuel system soon and have to decide if I stick with the recommended Van's design or venture to something else..... :rolleyes:

Mike.
 
I noticed that on the Spruce website there's a footnote regarding the Facet pump that says fuel will flow even when failed. Boviously this won't remove a dirt clog, but I wonder when this note was added and if this is a new feature.
 
Fuel Pump Problem

Just had a problem today with my facet fuel pump. Switched it on during my normal starting checklist and noticed I did not hear it come on as usual. Figuring it was my headset and dirty ears I continued with the start. After starting I noticed that my fuel psi was not coming up as it would with the boost on. Shut down the engine and listened for the fuel pump. It was making the same noise but much quieter and little to no pressue. There was fuel flow because the engine ran fine at idle and at 1500rpm. Switching tanks did nothing.
Could it be debris? I have no filters before the pump. I have only 60 hours on it.
Anyway, before I replace it and see what the problem was I want to know if anyone has had a similar experience. It is the little box type sold by Vans.
Really a bummer because the weather is gorgeous and my daughter and I were gonna fly somewhere to eat. :(
 
Someone reported a while back that theirs clogged up from debris from the tanks, like AL shards. Definetely check for this.

Roberta
 
You must log in or register to reply here.