in-line electric fuel pump with mechanical pump

[willy]

I have a stock 68 r/t with a 440hp. I would like to add an in-line electric fuel pump with a switch to pump fuel into the carb after it has been setting for a while so the engine doesn't have to crank a lot to get the fuel into the carb. Is this OK to do and still run off of the mechanical pump?
Thanks,
Willy

[femtnmax]

Yes, mine and others have set up this very system to prime the carb(s).  One issue is can the mechanical pump "pull" thru the electric pump for all types of driving.  The answer is sort of a test and experiment.
A set up I have is one of those square type electric pumps from carquest, and a carter mechanical pump pulls thru fine on a 416.   Another set up I've seen is a carter HP electric pump and the mechanical pump is fine on a IH 345 truck; but the same electric pump on a 440 dodge the mechanical pump won't pull thru enough after long uphill climb.  This is on a 1 ton fire truck, the owner turns on the electric pump until over the hill and he calls it good enough.
The electric pumps suggest having an in-line fuel filter between the fuel tank and pump, mount pump back by the tank and as low as possible so pump doesn't start 'dry' when you turn it on.  Hope this helps.

[willy]

Thanks Phil for the info. I wonder if it would help to add a check valve so the fuel could only go one way?
Willy

[Long Island RT]

It's cheaper to just fill the carb through the vent tubes when needed. That's what I do.  I use a cheap plastic pipette that fits in there snug.  It only happens after sitting for over a month or so....  When sitting for a long time - I put a piece rubber hose from one vent tube to the other - no more evaporation or gunky gas.  I have a Holley though - not sure what carb you have.

[willy]

I have an edelbrock carburetor and it will evaporate the gas out of it in less than 2 weeks. Does anyone have a recommendation for an electric in-line pump that the mechanical pump will pull through?

[femtnmax]

Some say a one-way check valve helps, but just like you said, the fuel evaporates out of the float bowl in less than 1-2 weeks depending on the season, so check valve won't do much there.
The electric pump I'm using is from carquest, label says:  Facet automotice electric fuel pump, below that says: UL listed 574A.
Carquest said they sell alot of them for boats.  Its a small pump, so probably not up to long term use as the only way to get fuel to carb...but works for me real well as a priming pump and pulls thru just fine.  I wired it so only active when key is "on".  I have a toggle switch just for the pump.  When I run the pump, you can here it slow down as float bowls fill and needle/seat starts limiting fuel flow.  Then I turn off elec pump and fire up the engine.
I used to do the fill the float bowl method, but it was necessary all the time, thought I'd wear out the air cleaner wing nut:)   Hope this helps.  Phil

[Manifold]

This is the little guy I run for carb priming: http://www.summitracing.com/parts/PFS-10701/

Have had no problems with my Carter 6903 pulling through it, or it pushing through the 6903.