Location of electric fuel pump, 41 cadillac

[robert G. smits]

I have read volumes of search material and John's excellent article in the self starter.  I still have 2 questions.
1)  How important is the location of the electric pump?  The PO of my car had the pump mounted in line and above the rear axel.  Trying to mount the pump near the gas tank and as low as possible is difficult.
2)  When driving in 100 degree weather here in Texas is there a down side to simply leaving the Electric pump on all the time?  It is a 2.5 to 4# rotary vane and wired through the ignition and has a second manuel shut off switch.  Thanks, Bob Smits #2426

[John Washburn CLC 1067 Sadly deceased.]

Bob,

Thanks.

I would suggest that getting the fuel pump to where the gas will flow to it is what matters. Something about gravity. If the gas can get to the electric fuel pump it will push it up to the carburetor. So close is good, but I generally mount them on the frame at the rear of the car.

While it does not get as hot here in Colorado we have the altitude to contend with. So on many occasions, especially in the mountains (I live at 6,000 feet, so the mountains are higher) one leaves the electric fuel pump on all them time. On my 37 LaSalle it works fine with it running constantly as do the other cars.

My two cents worth.

John W

[Dave Shepherd]

Most pumps have no real pulling power and need to be below the tank, should no issue running the elec pump all the time other than the power consumption.

[robert G. smits]

Thanks for the replies.  If one is going to run the electric pump all the time why go to the bother of rigging a bypass system with check valve?  Bob Smits #2426

[76eldo]

The bypass line lets the fuel circulate through the lines and remain cooler.

Electric pumps will pull.  It's pulling the gas from the inlet at the bottom of the tank uphill out of the top of the tank anyway.  I use a small 12V fuel pump on a board to get gas out of cars I need to drop the tank on and it works just fine way above the tank.

I am sure it will help with vapor lock.  Modern fuels are just terrible for vintage cars.

Brian