Electric fuel pumps for part time use

[Ghoste]

I was thinking of adding an electric pump as a booster.  I have one of those Carter HP electrical pumps and I thought it might be useful for the drag strip and for priming the float bowls after the car has been sitting for a while.  Then, I thought the idea of having the pump sitting there but spending the vast majority of it's time turned off would just make it a hindrancve to fuel flow under normal driving conditions.  Am I right on this or should I just go ahead and put it on there?

[Chryco Psycho]

Ih ave generally used 1 or the other not both for eletrics Mallory are about the best in the street versions
I can`t see a mechanical pump wanting to pull fuel through a electric pump as a hot set up

[Ghoste]

I've known of a few people doing it and I have this pump just sitting here so that is why I started thinking about it.  But when I started looking at the pump and thinking about it only running part time, well...

Thanks, Neil.

[John_Kunkel]

There are two ways to rig an electric pump for part time use, either select a pump that will allow fuel to pass through it when not running (most common pumps won't pass fuel)  or plumb the pump in a parallel circuit with a check valve to prevent backflow to the tank when the electric pump is energized.

[Ghoste]

Well, after looking at the pump again and thinking about using it for continuous duty, I see it also has 5/16 in and out to it and the rest of my fuel system is 3/8.  Is a lower performance electric going to make much difference really?
I don't seem to have fuel delivery problems with the current setup so I'm coming to the opinion that this electric may as well stay sitting on the shelf for now.

[firefighter3931]

If it's working fine and you're not experiencing any fuel starvation issues why mess with it ? The carter HV street pump and a 3/8in line will feed 600hp, no problemo. 


Ron

[Mefirst]

If it's working fine and you're not experiencing any fuel starvation issues why mess with it ? The carter HV street pump and a 3/8in line will feed 600hp, no problemo.


Ron

Would that same HV Carter pump still be up for the job if the HP the engine puts out is about 700Hp??? I just hate the whining noise from the electrical pumps...

/Tom

[Ghoste]

lol, I don't know if you could hear it whining in my car.
My main interest in installing one was to flip a switch and get fuel up to the carb after the car sits for a week instead of cranking the engine over and over.

[firefighter3931]

If it's working fine and you're not experiencing any fuel starvation issues why mess with it ? The carter HV street pump and a 3/8in line will feed 600hp, no problemo.


Ron

Would that same HV Carter pump still be up for the job if the HP the engine puts out is about 700Hp??? I just hate the whining noise from the electrical pumps...

/Tom

Tom, a mechanical pump will be hard pressed to adequately supply 700hp under hard launch situations, inmo. In that scenerio an electric pump out back to push the fuel forward to the mechanical pump would work.

Ron

[Ghoste]

My next stupid question would be why does the electric have 5/16 in and out to feed 3/8 lines?  Yes I know the pump is not application specific and yes I know that not all pumps have the same size.  It just makes me curious that the Carter mechanical pump of roughly the same capability is set up for 3/8 and the electric is not.  Are they really that much more efficient that they will move an equivalent amount of fuel with smaller lines?

[Chryco Psycho]

this often is the case where the fittings & or body of a pump is restrictive , I generally open them up as much as possible before installing any pump

[Ghoste]

I don't think I could open this one up much Neil.  It's supposed to flow 72gph at 7 pounds which is about the same as the Carter mechanical but it doesn't seem possible with a smaller inlet.  It isn't much smaller and the impact on volume would be much less than an entire fuel line of course but it is still a restriction.
I decided to leave it on the shelf anyway so now this is more about satisfying my curiousity than anything.

[firefighter3931]

I don't think I could open this one up much Neil.  It's supposed to flow 72gph at 7 pounds which is about the same as the Carter mechanical but it doesn't seem possible with a smaller inlet.  It isn't much smaller and the impact on volume would be much less than an entire fuel line of course but it is still a restriction.
I decided to leave it on the shelf anyway so now this is more about satisfying my curiousity than anything.

The carter electric pumps aren't generally considered a performance pump....more of a stock replacement. The HV Carter mechanical pumps are good for 120gph at 6-8psi. The holley and Mallory electric pumps all start at 110gph and go up from there.


Ron

[Ghoste]

I guess I didn't realize the volume was that high on the mechanical pump.  I was figuring by the pressure that it was lower volume than that.
I did know this Carter was more of a stock replacement than an actual performance pump which was why I had originally thought of it more as a booster.
Clearly, it would be a big component mismatch to try and use them together.

[Steve P.]

I guess I didn't realize the volume was that high on the mechanical pump.  I was figuring by the pressure that it was lower volume than that.
I did know this Carter was more of a stock replacement than an actual performance pump which was why I had originally thought of it more as a booster.
Clearly, it would be a big component mismatch to try and use them together.

The electric pump is constantly moving fluid when energized. The manual pump moves one pump volume per revolution. I know what you mean though. When looking into the fittings it doesn't seam plausible that so much fluid could get through those little holes so quickly.

[Ghoste]

Right, I never thought of that.  There is an equal volume of fuel that can be used within the fuel lines in both applications but the one is not accessing that volume as often.  I left out the time part of the fuel delivery formula.  Thanks, Steve.