Vapor Lock - Electric Pumps

While reducing the amount of heat gained by the fuel is helpful, the easiest and most reliable way to keep fuel from vaporizing in the fuel lines is to increase the fuel's pressure.  This means either replacing the mechanical fuel pump completely with an electric fuel pump or adding an electric fuel pump to supplement the mechanical pump.  In either case, an electric fuel pump should be located near the fuel tank and must have at least the flow rating of the mechanical pump and no greater output pressure than that required by the carburetor.

Many aftermarket universal electric fuel pumps are rotary vane style which is  positive displacement design and does not flow-through very well.  Rotary vane pumps can "dead head" (ie, pump with very little flow) The P4070 pump has an internal regulator, and therefore can bypass internally when reaching max pressure.  Rotary vane pumps are self-priming and can lift fuel on the suction side.  The vanes are lubricated by the fuel so it is not good to run the fuel tank too low.

Solenoid-style pumps are another common aftermarket fuel pump and these are generally a flow-through design. These pumps have an internal piston that produce a pulsating flow, somewhat like a mechanical pump and the internal valving allows the pumps to produce flow the necessary flow. Although solenoid pumps are also self-priming, they're not made to draw fuel and rely on tank pressure (via gravity and atmospheric pressure) to siphon fuel from the tank.

A fuel pressure regulator may also required if the pump's output pressure is higher than the carburetor's required fuel pressure. This is usually required on racing applications where the high volume fuel pump puts out much more pressure than the carburetor requires.

Most pumps have threaded connections where hose barb nozzles are screwed in.  For non-racing applications, these threads are typically NPT (National Pipe Thread) or NPSF (National Pipe Straight– Fuel) or NPTF (National Pipe Taper – Fuel).  NPSF and NPTF are also known as "Dryseal" threads and are designed to be used without PTFE tape thread sealant.  NPT threads require either pipe dope or PTFE tape to seal the threads from leaking.  Check which threads are used on your pump.

With any electric pump, it would be wise to install an oil pressure safety switch that stops the fuel pump when the engine stops.  Fuel pump manufacturers also generally require filters or strainers upstream of the pump to protect the pumps from wear and not having one could void your warranty.  Use the manufacturer's recommended micron rating for the pump filter and this may be coarser (larger) than what' required for the carburetor.  Carter recommends 60-100 micron filters for their pumps.  Carter reports that the most common cause for failures are wrong application or incorrect mounting.  Make sure you get the right pump and follow the manufacturer's installation instructions.

Oil Pressure Safety Switches

Fuel Pump Filters