installing a backup fuel pump

[Graham Mac]

Any tips or schematic drawings on installing a facet electric fuel pump as backup to diaphram pump??ROTAX 582 BLUE TOP..BING 54 CARBS.
any do's or dont's that one should be aware of?

[Tracer]

Hi,

Lengthy discussion here.. viewtopic.php?f=13&t=309&st=0&sk=t&sd=a&hilit=facet

[John Young]

And here -

viewtopic.php?f=13&t=3840

Unfortunately some of the punctuation went giddy when the forum was changed over.

Regards
John ZU-sEXY

[John Young]

And here -

viewtopic.php?f=13&t=3840

Unfortunately some of the punctuation went giddy when the forum was changed over.

Regards
John ZU-sEXY

[Graham Mac]

Thanks Tracer/John
Lots of reading there
still a few uncertainties...like facet pump pressure rating??? ....vertical or horizontal below or above tank?????
series or parralell fitting?????...oh decitions decitions decitions ....will go the series below or level with tank way...install pump vertically.test and hold thumbs

[John Young]

still a few uncertainties...like facet pump pressure rating???

3 psi

vertical or horizontal below or above tank?????

Vertical is best but not less than 45 - can prime to one metre - but halfway up the tank is good.

will go the series below or level with tank way...install pump vertically.test and hold thumbs

Yip - I agree, go series before your in-line fuel filter. Parallel requires an awful lot of plumbing.

Regards
John ZU-sEXY

[tandemtod1]

Never seen an absolute pressure rating as stated by the manufacturer but from experience they deliver between 1.7 psi to 2.4 psi which is well within the spec for your needle and seat capability. The facet fuel pump was designed for automtive use for carburettor fed engines and will therefore suit your application perfectly. As a backup pump you always plumb it in series to your existing pump. The non return valves in the facet pump are very low pressure so your diphram pump won't have any problems sucking through them when it is turned off.
As far as mounting hight is concerned, wherever it is most convenient, bearing in mind that the lower you mount it, the less work it has to do, but it will suck from above the tank as well.

[Graham Mac]

Thanks ttod..input and advise apreciated

[Trikenut]

If I may ask... which place is better to put it - before the filter or after it??
And also, is it alright to mount parrellel to the tank, but @ the bottom? (See pic)

[Morph]

It doesn't really matter but for safety I put it after the fuel filter so the pump doesn't have to digest any gunk.

[tandemtod1]

I agree with Morph that the pump should be protected from injesting gunk by fitting the filter in front of the pump. It is OK to fit the pump undeneath the tank as per your photo but make sure on your pre flight inspection that you carefully check all the hoses and clamps because if one or the other fail in flight, your fuel tank will empty itself. What do you mean by "parallel" Are you running the pumps in parallel with each other. If so, generally speaking this is not a good idea as you need a lot of extra plumbing which gives you more components which can fail with age and vibration etc. The norm is to run the two pumps in series with each other ie tank to electric pump to the diaphram pump to the carbs. This is usually simpler and more reliable.

[Trikenut]

Hi,
When I say parralell I mean like in the pic. Basically mounted on the rear pylon (like pic) but have it at the same height as the bottom of the tank instead of putting it above or below. In other words: is the pump strong enough to pump from the position at the bottom of the pylon??
Will the pump, if it is after the filter, still be strong enough to pull the fuel through both the filter and lines if there is a clog?

Yip - I agree, go series before your in-line fuel filter. Parallel requires an awful lot of plumbing.

Maybe I'm being an idiot, but what does this mean??
Oh and finally: Where do you put yout fuel flow sensor when the pump has been installed?? Before the pump or after??
Thanks
Ross

[tandemtod1]

Hi Ross,
I get the picture now on the paralell bit and what you have done there is fine. It really doesn't matter where you mount the pump as it is rated to give 60 litres an hour with a positive feed and 40 litres an hour with a 3 foot (approx 1 metre) suction line feed so the pump will be strong enough to feed your engine with a good surplas capacity.
"GO SERIES BEFORE YOUR INLINE FUEL FILTER" You are only an idiot if you don't know what this means after it has been explained to you, so for now you have an excuse. Series means as I detailed (not explained) in my previous post: From the tank to the filter to the Facet to the diaphram pump to the carbs, in other words in one and out the other.
As far as that item above that you highlighted is concerned though, I recommend that you put the facet pump AFTER your inline filter and not before as sugested by that post as the requirement of the filter is to stop any dirt or foreign matter getting into your pumps and carbs which will cause expensive damage. Check you filter visually on your preflight inspection and replace every 50 hours or sooner if you can see dirt in it.
"IS THE PUMP STRONG ENOUGH TO SUCK A CLOG THROUGH THE FUEL LINES AND FILTERS" A clog is a wooden shoe worn by the Dutch in Holland. If you get one of those in your fuel line, you will need more than a Facet pump to bail you out of the kak. Seriously though, if your filter has dirt in it to the point that the flow is impeded so that the motor is starved of fuel, then the more pump suction power you have, the more effectively it will stay blocked. This is not a good reason to fit the filter after the pump as it is the filters job to collect this crud to protect your pumps. Rather it is the reason to use a see through filter which you can inspect visually and change at regular service intervals or as required.
Fuel flow sensors in my experience tend to react more accurately to positive fuel flow than to suction line flow, so if possible mount it between the diaphram pump and the carburettors.
I hope that about sums it up for you. If you have any more questions, feel free to ask, but not tonight as I am old and dosing off now and all typed out.

[Trikenut]

Hi tandemtod1,
Thanks for the info!
I now completely understand!
So, to sum it all up: Put the Facet Pump AFTER the fuel filter, put the fuel flow meter in between the diafram pump and the carbs, and you are dozing off!
Can you give me the link for a Facet pump?
What does he mean by, "vertical or horizontal, above or below the tank"?
Thanks
Ross

[cjkrit]

I have done the series installation and it works well. Starting so much easier after a long stand. I have also added another fuel filter between the tank and the Facet pump- they are so cheap and worth replacing regularly.