Electric fuel pump backup...series or parallel with mech. one?

[TX Mudder]

I have a Holley elecric fuel pump from another project and don't need it for the other project anymore, so I thought I'd hook it up as a backup.

DO I have to bypass the mechanical one? If I activate the electric one, will it pump gas THROUGH the mechanical one? I know the electric one will not allow gas to go through it if it is off.

Anyone know? It would be so much easier if it does do this, as I want to put the fuel pump by the tank and don't want to have to run an extra line all the way up to the carb.

 

[Hossbaby50]

I don't think the mech pump will allow gas to pass threw it when it is not pumping. I would just splice into the fuel line after the mech pump and connect the elec. on a line that bypasses the mech.

Harley

 

[mouse]

The real gain from an electric fuel pump is by eliminating the parasitic loss the mechanical pump causes on the timing gear/cam. If you use the electric pump buy a block off plate - couple of bucks- and save a few horsepower!