Thread: Electric Fuel Pump

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I've always used some sort of exhaust pipe rubber hanger to mount electric pumps. It isolates the noise from the car pretty well. I did a search for a pic, but couldn't come up with the ones I used to buy (Pep Boys). Here's an example of what I'm talking about.....
http://www.automedia.com/Exhaust_Han...es20020401eh/1
These are not exactly the ones I've used, but should be better than solid mounting or rubber pads between the pump and mount point.

The other thing is, it sounds like you have the lines routed deadhead. The pump may run cooler and quieter if you run a return line with a regulator to set pressure at the carb inlet to around 5 1/2 lbs.

Here's a cute little exhaust insulator I found at Jegs that might work well and look sanitary also......
http://www.jegs.com/webapp/wcs/store...-1&showValue=1

Thanks Mike.

I am using a GM pump part number 25115899 that pumps 72 gallons per hour at 6-8 psi outlet pressure. It comes with a rubber insulated mount and is still loud.

If you do not run a return line to the tank, a Holley pump will run hot and puke out on you. Mine lasted one year and left me stranded 30 miles from home. I replaced it with a Mallory unit which has no outlet for a return line, and it has served me well for over a year. It has a different internal design than the Holley units.

The Mallory pumps are Gerotor type. The Holley blue, red, and blacks series are rotary vane type pumps. Gerotor pumps are much more rugged than RV pumps and also have superior suction qualities over RV pumps in general. And, surprise surprise, the Gerotor pumps are more expensive. Holley also makes Gerotor pumps and they are slightly less expensive than Mallory pumps according to what I've seen on Summit.

My suggestion for purchasing electric pumps;

1) Buy a Gerotor style pump
2) Use an oil pressure cut off switch with it if possible
3) Don't use too much pump. For gasoline, natural aspiration you need 8-9 GPH per 100 hp.
4) For max perfromance and cool factor buy a pump with 12-14 psi and use a bypass style regulator with return line. This will make it very hard for you to overheat the pump or experience vapor lock.
5) Use 15-30 mic screen before pump and 10 mic filter after pump.
6) Use minimum 3/8 line suction and supply/return. Avoid 90 degree elbows close to carb, curved tubing or hose better
7) Mount pump using 3/16 rubber pad to frame
8) Use a relay switch with the pump. You may also want to use a hidden toggle for added theft prevention

I think that gets most of it ...................

Kitz

You nailed it, Kitz!

What is the voltage at the pump terminals?

Most times electric fuel pumps end up at the end of a long line and low voltage makes them run hot and burn up pretty fast.

It's not uncommon to see a 2 volt difference between voltage at the battery and at the pump.

Use a continuous duty relay, feed the relay with 10 gage wire and control the relay with the long run of wire from the ignition switch or wherever your source wire terminates.
14 gage is a good size for this wire.

If the relay is close to the pump, you'll have voltage within a few hundredths of battery voltage.