installation of 12V fuel pump on 39 Ford
 

Need help to replace mechanical fuel pump with 12 V pump. Have 59 AB flathead in my 39 Ford converted to 12 Volt. What replacement 12 V pump should I buy. How do I deal with stock pump in tying in line from new pump. I assume I can catch power from the ignition to the new pump mounted at the gas tank.

Any pointers is greatly appreciated.

My 39 is a daily driver and have had 2 fuel pump failures in the last year with the mechanical pump.

Thank you

Re: installation of 12V fuel pump on 39 Ford
 

If it is the original ignition switch it was not designed for much of an amperage load. It is a better installation to pull power off of the fuse panel (hot side) and use either the ignition switch or a separate toggle switch to control the relay. If the electric pump is going to run full time an impact switch is also a good idea.

Re: installation of 12V fuel pump on 39 Ford
 

ditto on the original ignition switch having trouble with current loads. Set mine up with a couple of high load relays and thats all it runs about 5 amps everything else is run through the relays as for the fuel pump seen them done several ways like oil pressure switch with primer button or the best ive seen is a propane supply relay [powers the pump for 15 seconds when you turn it on then nothing until it gets a signal from the coil that is working [engine running ] as the last thing you want is the fuel pump working flat out when the engine has stalled

Re: installation of 12V fuel pump on 39 Ford
 

I used an inexpensive one from NAPA a few yrs ago and installed a dedicated fused circuit with a toggle switch under the lip of the dash..Verify the pump pressure from the elec pump.You might have to use a pressure regulator to bring it down to 2.5 lbs.

Re: installation of 12V fuel pump on 39 Ford
 

Check this website. Summit lists several pumps, and one may suit your needs. I have a 6v on my '46 with a filter on the inlet of the pump, and only use it to "prime" the mechanical pump/carb if the car has been sitting for several days. These pumps are "pull through" design, so you can still use the mechanical pump. The one I installed is low pressure, so I didn't have to use a pressure regulator.
https://www.summitracing.com/int/par...8090/overview/

Re: installation of 12V fuel pump on 39 Ford
 

The Facet self regulating pump from Purolater in Elmira NY, Made in USA. Who knows where stuff from other suppliers comes from.
The Facet is used on experimental aircraft if that gives you an idea of reliability, and sold by Aircraft & Spruce. The pump is self regulating, that means it maintains the pressure range of the unit you selected. Look at the chart of the pumps and you can select the GPM you want and pressure range. Purolater has great tech help if you need it. This pump in the photo is in the roadster, with a filter that screws into the pump, in the supply line from the tank.

Re: installation of 12V fuel pump on 39 Ford
 

I use a 12V Facet like "russc" showed above. Pressure is 4 psi for a Holley 390. Use rubber mounting pads.

Re: installation of 12V fuel pump on 39 Ford
 

I used an AC motor driven pump on my 1948 in 1956. I mounted it so the diaphragm hung down. (Of course that is right it's just like the mechanical one!) Nope! It crushed the float on the carburetor and I was out in the weeds trying to drive a flooded engine back to home. Borrowed a pressure gauge a friend had for a Paxton supercharger set up and found it was unregulated installed that way. With the diaphragm on top in it's little tower all was well.

Re: installation of 12V fuel pump on 39 Ford
 

I apologize in advance since this is not an answer but why wouldn't an original pump properly rebuilt for modern gas work? Who is doing your rebuilding and are they using the proper parts? I don't remember hearing that the original pumps were that bad, how are yours failing?

Charlie Stephens

Re: installation of 12V fuel pump on 39 Ford
 

Facet pumps are very well made and depedable pumps, but they are very noisy with an irritating loud buzz. The one in my roadster was rubber mounted and even that did not help.

I now use a carter rotary pump which is quiet. Had one in my model A Tudor for 10 years.

John

Re: installation of 12V fuel pump on 39 Ford
 

I'm glad to find out not to wire the pump up to ignition switch, which I just did, gona change it to the fuse block. Thanks Al

Re: installation of 12V fuel pump on 39 Ford
 

I am not sure what is making the pumps to fail. Last Sat I was driving and it just stopped. No gas coming through, 5 gallons in the tank. I think it is related to the fact that I don't drive my car enough. It sits for months at a time. Two pumps definitely have failed. Also it is hard to get the pumps primed when sitting and gas dries up. I pour some into the carb, but this is a pain and easy to flood the carb.

Thank you for your comments and any other suggestions

Re: installation of 12V fuel pump on 39 Ford
 

I am not sure what is making the pumps to fail. Last Sat I was driving and it just stopped. No gas coming through, 5 gallons in the tank. I think it is related to the fact that I don't drive my car enough. It sits for months at a time. Two pumps definitely have failed. Also it is hard to get the pumps primed when sitting and gas dries up. I pour some into the carb, but this is a pain and easy to flood the carb.

Thank you for your comments and any other suggestions

Re: installation of 12V fuel pump on 39 Ford
 

Are the pumps failing or is there other factors.


Tank clean? New lines? Filter inline?


I think most run the airtex. I have a 12v carter (nice pump) that I bought but never used. Still using a mechanical pump. With a rotatory carter you need a bypass line with a check valve.