What are the pros and cons of using an electric fuel pump? Which one do I need to use? Or stick with mechanical one,where to mount etc. Thanks 55birdman

55Birdman  Hickory NC

Bird: First, are you having a problem with the mechanical pump?..

Paul

Make sure you get a low pressure model suitable for a carby, not the high pressure ones that are used on fuel injected engines. One problem is that as long as the ignition is on the pump is running, so if the engine stops for some reason the potential is there to pump the contence of your tank onto the floor. A inertia safety cut off switch would be wise  in case of a vehicle accident.  

Pete, one of the Aussie mob. Beechworth, Victoria60 F100 Panel Van, Y-block. 65 Galaxie Country Sedan 390

With the electric pump, vapor locking is no longer an issue.  Depending upon the electric pump being used, noise level could be on the high side.  Electric fuel pump location is important for the life of the pump and consistent performance.  Pumps need to be mounted close to and at fuel tank level for best performance.   How the pump is wired up needs to be considered as it must not be wired to a 'hot' source on a street driven vehicle where the potential is there for it to run when the engine is off (toggle switch control is a no-no).  Separate or dedicated wiring to the electric pump is also recommended.  Under no circumstance use the positive side of the coil for the fuel pump wiring.  As Pete mentions, some kind of inertia switch or oil pressure switch would be a nice safety feature.

 

Mechanical pumps give good performance when the fuel lines are in good condition and not pulling in any air on the suction side.  Engine heat is transmitted into the mechanical pump which can bring to the forefront the aforementioned vapor lock issue but then can be a fuel economy enhancer by having warmer fuel at the carburetor.  I’m talking warmer, not boiling here.  Mechanical fuel pumps on the Y engines have been trouble free for the most part so there’s no reason to just arbitrarily switch to an electric pump unless addressing another issue.

In the case of where a car sits for long periods of time without being cranked, then an electric pump does give the option of refilling the carb with fuel to facilitate quicker starting.

Lorena, Texas (South of Waco)

I like the oil pressure switch - you can get them from Holley, Carter, Summit - etc. Tee's in at the idot light port on the LH side of the block. The switch closes when there is pressure - opens when there's none. So you have to have oil pressure to keep it going. Engine dies - pump dies. Use a source from the ignition "on" to feed the switch - then go to a relay to power the pump.

A manual "intermittent" duty push button or toggle will let you run the pump prior to starting (or troubleshooting) by holding it in. Then let the pressure switch take over hold it on after the engine starts. There are ways to make the over-ride at start an "automatic" function.

 
 Steve Metzger       Tucson, Arizona