Fuel pump options

[36coupe]

I have been thinking of adding a electric fuel pump in line on the 36 as insurance or even a priming pump on a momentary switch. The car will be 12v.
I think I already know this won’t work but I have a couple of new airtex 6v pumps. What happens to a 6v pump with 12v? Pump twice as fast, same pressure? Catch fire? Probably be okay for a priming pump? I guess it would be cheaper to get a 12 volt pump than to reduce the Voltage in the long run.

When I get the car on the road I will probably have a spare mechanical pump in the trunk along with a coil and anything else that could be done with a road side repair.

[51504bat]

My '39 p/u is 12 volt and I run an electric pump set up just like you are considering. Don't know about using a 6 volt pump but why? I understand you have it but a proper 12 volt pump isn't that expensive and you know it will work. Why go through the install process of the 6 volt pump only to wonder if it will be an issue down the road? Spring for the 12 volt pump, install it, and forget it. JMO

[chap52]

You could add a voltage drop to the circuit. I ran 6 vt starter on 12 vt for years . Dod have to replace a couple of starter bendix springs. Chap

[36coupe]

Originally Posted by 51504bat

My '39 p/u is 12 volt and I run an electric pump set up just like you are considering. Don't know about using a 6 volt pump but why? I understand you have it but a proper 12 volt pump isn't that expensive and you know it will work. Why go through the install process of the 6 volt pump only to wonder if it will be an issue down the road? Spring for the 12 volt pump, install it, and forget it. JMO

I have time to work on the car since I’m not working. The 2- 6v pumps will probably never get used by me. Being north of the border everything in USD is twice in CAD by the time exchange and shipping is factored in plus I’m cheap lol.
I know the correct answer is just buy a new 12v pump.

[19Fordy]

Can you install a resister in the line to reduce the 12V line feeeding the pump to 6V?

I used a 60 ohm resistor to reduce the 12V feeeding my 6V BATT gauge.
Read post #6 here.
https://www.fordbarn.com/forum/showt...olt+conversion

Here's the resistor I used. Still working after 10 years.
https://www.westfloridacomponents.co...+Resistor.html

[Flathead Fever]

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There are two kinds of pumps. Ones that are closed when they are not energized and ones that stay open. If you are going to just use an electric pump to prime the system, it will need to stay open when its "not" energized so the mechanical pump will be able to draw fuel through it. Its best to just get the correct low pressure 12V pump that is open when not in use. That way if you need to use it as a backup pump it will be the correct pressure. The pumps you have might be 5-6 lb. pumps and which could cause carb flooding. See if you can blow through your pumps, if you can't, they will not work in-line with your mechanical pump.

[36coupe]

I have 2 airtex pumps, one is 2-4 psi and the other is 5-8 I think. Both will allow a mechanical pump to work.