fuel line

[Steve T.]

What is the correct route to run a fuel line with mechanical pump and a electric pump? Electric for priming and starting, and the mechanical for running. It's in my 1946 1 ton truck with a V8 flathead. Should I just run the line to the pump? The electric pump is on the frame close to the tank.
Might sound like a foolish question, I don't know.
Thanks guys
Steve T.

[Alaska Jim]

keep the electric pump as close to the fuel tank as possible. the electric pump "pushes" better than it "sucks". make sure that the electric pump you use is designed to be able to have the mechanical pump pull fuel through it when the electric pump is not being used. so in this order, fuel tank, electric fuel pump then run your fuel line to the mechanical pump then fuel line to carb . you should wire the switch for the electric pump to be hot only with the ign. key on. some also wire in a roll over switch, and some use an oil pressure switch that will not let the pump run with out oil press., but that would defeat your being able to use the electric pump for priming

[Mart]

I have that set up on two of my cars.

I use the generic typically British Lucas* pumps which are a solenoid and diaphragm type, not a revolving motor. (They go tick tick tick when working). I put them up on the bulkhead breaking into the flexy line that normally runs from the end of the hard fuel line to the mechanical pump.

I use a momentary contact switch to make them run. (I used a standard Ford starter button).

I use the electric pump to prime the carb after standing for a while, and then the mechanical pump takes over for normal running. In effect the electric pump just has two one way valves in it which the mech pump can easily draw through.

The advice re mounting the pump near the tank and having safety switches for rollovers are not applicable, in my opinion, if you have the right type of pump.

While only used for priming, there is the added bonus of it being able to get you home if there was a failure of the mechanical pump. (Other than a ruptured diaphragm.)

Mart.

*Edit: I said Lucas - I meant SU.

[Steve T.]

Thanks, Your replies are what I suspected, I am using a "Carter" brand pump I got from Mac's. I appreciate the reassurance you guys gave me.
Thanks again !

[Alaska Jim]

Mart, are those pulse type fuel pumps available in a 6 volt version in England? I cannot find one here in the US anymore. I do not use the rollover safety switch, or a oil press switch on my car with an electric pump. I just stated that it was an option, as there are several people on the ford barn that do use them and recommend them. I am currently using one of the revolving motor type of pumps, because when my old pulse type pump went bad, that is all I could find available. The one I used to use was an A/C Delco brand, no longer made in a 6 volt configuration

[Mart]

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Yes, but very pricey. I did find some on US ebay that look like they ought to work. If you search "fuel pump 6V assist or primar" You will see the ones I have just been looking at. Funny, if it's for a Plymouth it's cheaper than if for a Ford. Go figure. These might be the ones that are better at the rear end. I dunno. They are described as solenoid type.
This is the type I use but much cheaper second hand 12V units from old minis etc.

https://www.ebay.co.uk/itm/Fuel-Pump...gAAOSwZB9aP8Bz

I said they were pricey.

[Alaska Jim]

Thanks Mart, some very useful information. I may get one when this round motor type gives up , or I decide I don't like it enough to spend the money. The tax man is hitting me pretty hard this year.

[cmbrucew]

You might check for Holley pumps for six volts. Most carburetors need a pressure regulator.
Bruce