Replacing the mechanical fuel pump with an electric fuel pump is commonly done in high performance applications for improved fuel delivery and should eliminate vapor lock completely. This prevents fuel vaporization in the fuel pump from conductive heat transfer. After removing the mechanical pump, the fuel pump's boss on the engine block must be capped-off and a tubing splice to connect the two sections of gas line must be added. The electric pump should be mounted as close as possible to the tank and as low as possible to allow gravity to prime the electric electric pump. Follow the installation instructions of the electric fuel pump's manufacturer.
Often, the electrical systems in older vehicles were designed to only provide enough power to the limited requirements of the car. An electric fuel pump can draw several amps continuously, which can be a problem at idle due to the relatively low output (compared with modern cars) of the old generators and alternators at low rotational speeds. Reducing the generator/alternator pulley diameter can help to increase low RPM power output. Some cars can be easily upgraded to higher-output modern alternators but this upgrade requires that the electrical system also be upgraded to handle the additional current. Not taking the modern alternator's higher output into account risks electrical fires due to excessive current.
Electric fuel pumps generate noise and some pumps are louder than others. Unless you're building a race car, be sure to install the noise insulation parts that go with your particular fuel pump.
Look up the required fuel pressure required for your carburetor. If the pump you want to use has a higher output pressure, you need to add pressure regulator to prevent the pump from flooding your carburetor.
For a stand-alone electric fuel pump, you can use either a rotary vane or a solenoid pump. I recommend rotary vane pumps in this case because they have better lift and self priming capability.
AC Delco EP247 (6-8 psi, 72 gph) |
Carter P4070 (4-8 psi, 50 gph) |
Spectra Premium SP1130 (4 - 5.75 PSI; 72 gph) |
Earl's 128011ERL 7 psi, 97 gph |