Moparts

Fuel Pump question

Posted By: Hemi Allstate

Fuel Pump question - 04/21/12 09:30 PM

Guys, I got a little bad information when building my car. I have always mounted the electric pump lower than the fuel tank so it would gravity feed.
I was told that was not necessary any more! SO, I mounted mine in the trunk.
Now, it will not self prime and draw from the tank. It is a BG 220 HR.
My question is... Is there an electric pump, that will draw fuel up from the tank? Is a gear rotor pump capable of this?
Thanks,
Mark

Attached picture 7173774-CopyofHPIM3725.JPG
Posted By: rickraw

Re: Fuel Pump question - 04/21/12 10:14 PM

i beleive all pumps need to be mounted below the tank, unless it's in the tank. a pump needs gravity fed, then it can draw & push. looks like u have room by ur tank to mount it.
Posted By: Hemi Allstate

Re: Fuel Pump question - 04/21/12 10:20 PM

Quote:

i beleive all pumps need to be mounted below the tank, unless it's in the tank. a pump needs gravity fed, then it can draw & push. looks like u have room by ur tank to mount it.



Yes I do, but that would put it right behind the right rear tire, and I would rather not do that.
I put a check valve in between the tank outlet and the fuel filter. That helped, but it still loses prime overnight.

Attached picture 7173820-Copy(2)ofHPIM3723.JPG
Posted By: rickraw

Re: Fuel Pump question - 04/21/12 10:40 PM

u could put a shield around it. moving the pump would solve ur problem
Posted By: smokinwoody

Re: Fuel Pump question - 04/21/12 10:42 PM

looking at your picture Mark, looks like gas drains back in through the filter caused by the up swing of the fuel line...

when I start plumbing my Dodge, Im going to put a fuel shut off valve right at the tank...if you did that, the fuel will stay in the line rather than drain back...also a check valve may work in that line going forward..

I read that you dont want to lower the pump placing it behind the tire....I was going to say, place the filter below the pump but that wont change a thing...the culprit is that fuel line going up and over the tub.....
Posted By: DragDart360

Re: Fuel Pump question - 04/21/12 11:13 PM

(I was going to say, place the filter below the pump but that wont change a thing...the culprit is that fuel line going up and over the tub.....)

Posted By: astjp2

Re: Fuel Pump question - 04/22/12 01:14 AM

Dont over think it. Tim

http://www.ebay.com/itm/Race-Pumps-Fuel-...9e8&vxp=mtr
Posted By: Hemi Allstate

Re: Fuel Pump question - 04/22/12 03:00 AM



when I start plumbing my Dodge, Im going to put a fuel shut off valve right at the tank...if you did that, the fuel will stay in the line rather than drain back...also a check valve may work in that line going forward..

the culprit is that fuel line going up and over the tub.....



Jeff,
I did an experiment today. I took the top off the filter, and filled it to the inlet of the pump and put the filter back in. It ran and primed, just fine. 4 hrs. later it had lost prime. This is with a new check valve between the tank and filter.
I have tried removing the blue cap on the pump, and poured fuel in there and it will not prime the pump, or hold the fuel.
Posted By: smokinwoody

Re: Fuel Pump question - 04/22/12 05:51 AM

my brain is back in gear...cant flow back into or thru the sump because theres more gas (pressure thru volume) and the tank does sit higher..with the line running up hill over the tub, the fuel thats in the line below tank level should stay in the pump...a check valve would be a good idea if the line is kept like this...

something tells me your pump may be at fault..

I see you have a return line...so you capped off the return from the pump itself....that too maybe the problem...

I use the Aeromotive 2000 pump deadheaded with the bypass line from the pump to the tank...that keeps the pump cooler and wont lose its prime......I mount my pump even or slightly below the sump which also keeps a constant pressure of fuel to the pump..

why I say use a shut off at the tank cause,,have you ever disconnected the fuel lines up front and have gas come pouring out until you raise the fuel line way higher than the tank??...


I know you may not want to hear this Mark, but, if it were me, I would remount that filter and pump to get it at least even with the sump outlets...you can build a box around the pump if you dont want all the tire crap and dirt up around it...
Posted By: RobbMc

Re: Fuel Pump question - 04/22/12 06:48 AM

Using a return regulator and plugging the return at the pump (just like you have it) is fine. That is not the problem. A return regulator not only allows fuel to constantly flow through the pump to keep it cool, it also allows the pump to produce a lower pressure which reduces amp draw and temperature.
The problem is mounting the pump (especially a rotary vane pump)higher than the tank/cell.
It would be best if the pump was no higher than the tank. Having said that, if you must mount the pump higher, you'll have better luck with a gerotor style pump because the internal clearances are tighter so it will "suck" (prime) better (at least until the pump has substantial internal wear). However, the same tight clearances that make gerotor pumps prime better also makes them more susceptible to debris. Use a large 40 micron filter before a gerotor pump.
Posted By: Hemi Allstate

Re: Fuel Pump question - 04/22/12 04:07 PM




I know you may not want to hear this Mark, but, if it were me, I would remount that filter and pump to get it at least even with the sump outlets...you can build a box around the pump if you dont want all the tire crap and dirt up around it...




Jeff,
I know this is the logical answer, and I am looking at how it could be mounted, with a minimum of changes, or mods, to the parts that are already painted!
Is there and electric fuel shut off that has -10 AN fittings? I could replace the check valve with that and .........
Thanks,
Mark
Posted By: Hemi Allstate

Re: Fuel Pump question - 04/22/12 04:17 PM


It would be best if the pump was no higher than the tank. Having said that, if you must mount the pump higher, you'll have better luck with a gerotor style pump because the internal clearances are tighter so it will "suck" (prime) better (at least until the pump has substantial internal wear). However, the same tight clearances that make gerotor pumps prime better also makes them more susceptible to debris. Use a large 40 micron filter before a gerotor pump.




Robb,
This is what I was thinking. The oil pump in in the BBM engines are gerotor type, and they pull oil up from the pan which is of course lower.

I want to look at all options, before making a change. The tank is 12" tall, 7.5" is level to the pump inlet. So I guess for now if I keep the tank/cell filled above that I will not have to reprime the pump!?!?
Thanks for your input,
Mark
Posted By: rickraw

Re: Fuel Pump question - 04/22/12 04:29 PM

not looking at ur car in person, can u raise ur cell up higher?? i have a mallory g-rotor pump, directions state pump must below sump or level with it. that maybe an option.
Posted By: Hemi Allstate

Re: Fuel Pump question - 04/22/12 05:20 PM

Quote:

not looking at ur car in person, can u raise ur cell up higher?? i have a mallory g-rotor pump, directions state pump must below sump or level with it. that maybe an option.



I don't think I can raise it enough to help. Also, it is enclosed in steel on the sides, and the outlet passes through it.
I am glad you told me about your Mallory, as that is one I am considering.

Mark

Attached picture 7174821-!cid_002001cc9c23$d8caf5b0$020492BD@MobileUnit1.jpg
Posted By: RobbMc

Re: Fuel Pump question - 04/22/12 05:52 PM

Quote:

Quote:

not looking at ur car in person, can u raise ur cell up higher?? i have a mallory g-rotor pump, directions state pump must below sump or level with it. that maybe an option.



I don't think I can raise it enough to help. Also, it is enclosed in steel on the sides, and the outlet passes through it.
I am glad you told me about your Mallory, as that is one I am considering.

Mark



I helped write the Mallory instructions. Yes, it is better if the pump can be gravity fed. It avoids a lot of customer phone calls with problems. For instance, if there is even a tiny leak in the line between the tank and the pump, the pump may not prime (ever try to suck through a straw with a hole in it?). Also, as the pump gets older, it doesn't suck as well. So, to be safe, it is better to have the pump gravity fed. Still, the Mallory gerotor pump will prime a lot better than the BG pump. When I was testing BG pumps on the bench many years ago, I found that the pump would only prime if it was placed on the floor below the fuel storage tank we had mounted on the bench. New Mallory pumps would prime even if 2 or 3 feet above the tank.
Of course, BG pump design may have changed since then, but this is my experience.
Posted By: RobbMc

Re: Fuel Pump question - 04/22/12 06:00 PM

Quote:


It would be best if the pump was no higher than the tank. Having said that, if you must mount the pump higher, you'll have better luck with a gerotor style pump because the internal clearances are tighter so it will "suck" (prime) better (at least until the pump has substantial internal wear). However, the same tight clearances that make gerotor pumps prime better also makes them more susceptible to debris. Use a large 40 micron filter before a gerotor pump.




Robb,
This is what I was thinking. The oil pump in in the BBM engines are gerotor type, and they pull oil up from the pan which is of course lower.

I want to look at all options, before making a change. The tank is 12" tall, 7.5" is level to the pump inlet. So I guess for now if I keep the tank/cell filled above that I will not have to reprime the pump!?!?
Thanks for your input,
Mark



Correct. If you keep the level of the fuel in the cell higher than the inlet of the pump, it should prime.
Posted By: Hemi Allstate

Re: Fuel Pump question - 04/22/12 07:22 PM

Quote:

Quote:


It would be best if the pump was no higher than the tank. Having said that, if you must mount the pump higher, you'll have better luck with a gerotor style pump because the internal clearances are tighter so it will "suck" (prime) better (at least until the pump has substantial internal wear). However, the same tight clearances that make gerotor pumps prime better also makes them more susceptible to debris. Use a large 40 micron filter before a gerotor pump.




Robb,
This is what I was thinking. The oil pump in in the BBM engines are gerotor type, and they pull oil up from the pan which is of course lower.

I want to look at all options, before making a change. The tank is 12" tall, 7.5" is level to the pump inlet. So I guess for now if I keep the tank/cell filled above that I will not have to reprime the pump!?!?
Thanks for your input,
Mark



Correct. If you keep the level of the fuel in the cell higher than the inlet of the pump, it should prime.



Robb,

Does the Mallory pump use a return line? Which pump would I use for this application?
Thanks,
Mark
Posted By: RobbMc

Re: Fuel Pump question - 04/22/12 07:48 PM

Mallory 250 pumps have an external bypass (return line from the pump). However, if you are using a return/bypass regulator, you will not use the return from the pump (just plug it).
Posted By: Hemi Allstate

Re: Fuel Pump question - 04/22/12 08:07 PM

Quote:

Mallory 250 pumps have an external bypass (return line from the pump). However, if you are using a return/bypass regulator, you will not use the return from the pump (just plug it).



Robb,
Thanks very much for your help. I will look into the Mallory 250 pump.

Mark
Posted By: Hemi Allstate

Re: Fuel Pump question - 04/25/12 03:15 PM



For instance, if there is even a tiny leak in the line between the tank and the pump, the pump may not prime (ever try to suck through a straw with a hole in it?).


Well, thanks to an observant friend that noticed fuel seeping out from the fitting between the filter and the pump, we have found the problem!
We removed the pump and filter and sealed the fitting (pipe threads) with teflon tape. I had to prime the pump by filling the filter again, but as of this AM the pump has not lost prime!

Thanks,
Mark
Posted By: smokinwoody

Re: Fuel Pump question - 04/25/12 06:09 PM

thats great Mark....

we all assume the worse..
Posted By: Hemi Allstate

Re: Fuel Pump question - 04/25/12 08:07 PM

Quote:

thats great Mark....

we all assume the worse..



Well in a way you were correct Jeff, when you said the pump may be at fault! The fitting leak was at the pump.

Thanks to all that responded.
Mark
Posted By: rickraw

Re: Fuel Pump question - 04/25/12 09:50 PM

glad u found the problem. probably saved some$$ too. not to a wise guy,u should never use teflon tape on fuel fittings. teflon pipe dope & very little is best.
Posted By: Hemi Allstate

Re: Fuel Pump question - 04/26/12 12:41 AM

Thanks rickraw,
I will remember that!
© 2024 Moparts Forums