Thread: Which Fuel Pump?

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There are many different ways to plumb a system effectively. I'll outline just one of them that I like for your consideration.

Coming right out of the cell, mount a cartridge type fuel filter such as the Mallory #3140 shown on page 114 of the link below.

Immediately after the filter, mount an electric fuel pump such as the Mallory #4150 shown on page 109 of the link below.

At the carburetor, mount a fuel log/fuel pressure regulator such as the Mallory #4302M shown on page 118 of the link below.

On the front of the log at the carburetor, before the carb inlets, mount a tee on the front of the log. Off this tee, run a small copper or nylon line back to the firewall and up to the cowl so that you can mount a mechanical fuel pressure gauge on the cowl and read it through the windshield. You will need to monitor fuel pressure throughout the rev range in order to properly set the pressure at the fuel log/regulator. HOLLEY SAYS TO USE MINIMUM PRESSURE 5 PSI AND MAXIMUM PRESSURE 7 1/2 PSI MEASURED AT THE CARB INLET. Use a gauge such as the Mallory #29724 shown on page 119 of the link below.

Use minimum 1/2 inch fuel line throughout your installation from the cell to the carb fuel log and for your fuel return line out of the fuel log back to the cell such as Mallory #28788 shown on page 118 of the link below.

http://www.malloryperformance.com/pd...m_Products.pdf

Pay attention to the min/max fuel pressures given by Holley. This is a carburetor. It is not fuel injection, where a higher pressure could produce more horsepower. The only thing you will accomplish by exceeding the max recommended fuel pressure at the carb inlet will be to over-power the needle and seat and blow raw fuel into the intake manifold, providing you with untold misery and turning the whole mess into a tuning nightmare.