Adding an electric fuel pump
 

I am in the process of adding an electric fuel pump (carter low pressure) that I plan to mount to the rear cross member, low in front of the tank. This is on a 1937 pickup. I will add a filter before the pump. I was planning on still using the stock fuel pump as well. Do I need to put a line with a check valve to bypass the electric pump when not using? Is there risk of fuel leaking internally on the stock fuel pump when using the electric? I do plan on adding an adjustable pressure regulator. This is with a stock intake and Stromberg 97. I may in the future switch to a slingshot intake and two 97s so I want to provide for that now.

Re: Adding an electric fuel pump
 

"Is there risk of fuel leaking internally on the stock fuel pump when using the electric?"

Yes, if there is a rupture of the diaphragm in the mechanical pump it will pump fuel into the engine.

"I do plan on adding an adjustable pressure regulator."

There are some cheap regulators that are just that, cheap. I would use a quality regulator.

I don't know if the Carter pumps are draw-through or not, but I don't think they are.

Re: Adding an electric fuel pump
 

I have an electric pump installed just after the tank with a filter in my '39 p/u with a stock 8ba and 94 carb. It's controlled by a toggle switch under the dash. I switch it on after it's been sitting for a while to fill the carb and then switch it. No check valve. No issue with the mechanical pump interfering with the operation of the electric pump.

Re: Adding an electric fuel pump
 

I would suggest that you take a look at an Airtex pump. They are a flow through design, and come in 6 or 12 volt with a variety of pressures so you wont need a pressure regulator. I have one on my ‘46 that I only run to prime the carb if needed, and I turn it off once the engine is running. I also installed a filter ahead of the filter.

Re: Adding an electric fuel pump
 

I believe that the Carter pump is a gear type pump and if it is I do Not think they are a Flow through Pump. kerk

Re: Adding an electric fuel pump
 

While you're at it, install a fuel line shut off after the tank but before the filter and fuel pump so that you can shut of the gas when you work on the filter or the pump. I used a radiator petcock but prettier shut offs are available. Works fine.

Re: Adding an electric fuel pump
 

My field expedient is a pair of vise grips to pinch the hose shut when changing the filter.

Re: Adding an electric fuel pump
 

I would also think about adding a safety cut off that will kill the pump in case of an accident. If you can locate a copy of the V-8 Times from July/August 1999 it shows how to do it.

Re: Adding an electric fuel pump
 

I pulled a fuel shut off switch out of a Taurus and installed it behind the drivers side kick panel. Thankfully I haven't had the chance to actually use it.

Re: Adding an electric fuel pump
 

This thread is perfect timing, I've actually been tinkering with my fuel system the last few days. I've read so many gas siphoning back to the tank.... carb leaking into the intake.. bad fuel pump shaft or cam lobe threads it will make your head spin LOL. Keeping my fingers crossed I took my brand new fuel pump apart, blew thru the lines and found the check valves were leaking. Clean and reseated the check valves, much better. Been sitting for 3 days, going to try tonight to fire it up. Still thinking about the same thing as the original poster. Just put in low pressure pump for priming and be done with it. Save a whole lot of cranking.

Re: Adding an electric fuel pump
 

Vise grips don't work too good on hard lines. Otherwise good idea.

Re: Adding an electric fuel pump
 

That is an issue that can be resolved on the spot by simply holding the line up higher than the source. The thing about that, of course, is the need for another hand to do that! It can be done, though, but you still need to remember to not be laying directly under the fuel line you open up. :eek:

Re: Adding an electric fuel pump
 

I put a "service loop" in the hose before and after the pump, which makes the vice grip clamp-off easier. All tucked up inside the frame rail just in front of the rear axle. Rather do that than add valves which are another potential source of a leak.

I am going to go back and rubber mount the pump because the constant buzzing annoys me. Back in the day I used a Bendix electric fuel pump mounted on the firewall of my '35 coupe. It clattered, but shut off when the pressure came up. The gas gauge on that car never worked, so constant pump clatter was a sure sign that I had pushed my out-of-gas estimate too far.

Re: Adding an electric fuel pump
 

Good points. Never realized that the potential of a radiator petcock leaking may be great especially after using it for 20 years. Since I want to use hard lines perhaps I should try one of these.
https://www.jegs.com/webapp/wcs/stor...rsistYmm=false

My electric fuel pump also uses hard lines with the pump mounted on rubber.

Re: Adding an electric fuel pump
 

I put a electric from Macs on my 55 crown and used it for starting after sitting for a while..After a bit I found if I drove over 40 orso it would start slowing down as if lacking for fuel.I took the pump off and connected the line straight to the mechanical pump and it works fine..So beware of pull through electic pumps..

Re: Adding an electric fuel pump
 

I my thread here, "What I Did on my Lunch Hour", I detailed the conversion of the OEM fuel pump to a "passthrough" so you can use an electric pump (I use Airtex) as the primary and not have to worry about the OEM pump failing and allowing fuel to get into the crankcase. I also install a "kill switch" to shut off the flow of fuel if it becomes necessary. I'm not a fan of combining the OEM with an electric pump as a primer. If you want to maintain the "stock" appearance under the hood, and eliminate any possibility of the OEM pump failing, this is the best way to do it, in my opinion. I have converted the OEM fuel pumps on all my Flatheads (6 & 12 volt).