5 replies to this topic

[Agus1601]

Hi guys! I would like to sort this out and try someone to make me understand what are the pros and cons and which one would you prefer for a once a week use.

 

Thanks a lot

Agustin

[nicklouse]

Neither is really better or worse.

But not having the mechanical one does mean that for some applications you have less heat transmitted from the exhaust to the fuel.

Really it comes down to what you are building.

[dklawson]

To expand on Nick's comments....

 

If you mount an electric pump in an adverse location (like low on the firewall behind the engine) it may get hot.  Electric pumps are usually best mounted at the rear of the car below the level of the tank.  Pumps work better as pushers than pullers.  

 

Regardless, there is nothing inherently better about one type of pump vs another.  Mechanical pumps are pretty bullet proof and run for years without issue.  Changing to an electric pump often requires you to add wiring and safety switches to insure the pump stops in the event of an accident.  However, electric pumps can be advantageous on cars that see infrequent use.  With an electric pump you can turn the ignition key to the run position and allow the pump to fill the carb float bowl before you turn the engine over on the starter.  This can make infrequent starts easier and quicker.  

 

On a daily driver that already has a mechanical pump I would keep the stock pump but that is just my personal opinion.

[Trissy B]

I've got the standard SU pump on the rear subframe which has stopped working. Would it be better to replace like for like or what about the facet pumps? I thought these were uprated but they are cheaper!

[dklawson]

If your car has an electric SU pump that has stopped working, test it and fix it.

 

Remove the plastic cap from the end of the pump.  Fold a piece of very fine wet/dry sandpaper in half and slip it between the pump points.  Draw the sandpaper out.  Repeat this several times for each of the two points.  Now drag a piece of cloth through the points to remove any abrasive grit.  Replace the pump cap and see if the pump works.  If it does, the pump will be serviceable for some time to come.  You can clean the points several times before they are worn out.

 

If you cannot get the SU to work, then consider a Facet or other aftermarket pump.  Don't spend money if you don't have to.  Remember to buy a very low pressure Facet pump.  If it supplies more than 3 PSI you will need to add a pressure regulator to drop the pressure down to 2 to 3 PSI.

 

EDIT:  No, the cheap Facets are not necessarily uprated.  Almost any pump you find will deliver enough fuel for a street car and you want to keep the pressure in the range I mentioned above.

Edited by dklawson, 08 April 2016 - 12:44 AM.

[Trissy B]

Thanks, will do this... if it doesn't work, Mini Sport do a facet road kit that's well priced.