electric fuel pump

[will6318]

ok i have a ? i i keep the stock fuel tank what needs to be done to run an electric fuel pump do i need a regulator i am going to be running a 383 with a 700 holley double pump. so any help on how to put an electric fuel pump in my ca i would appreciate.thanx
:?

 

[pontiacgp]

if you know what hp you have you can use this equation to figure out how much fuel you need to pump....

(hp x 1/2) divided by 6 (the weight of 1 gallon of gas) = gph

a stock mechanical pump on a 350 is rated at 60 gph

 

[will6318]

thanx for the advice it really helped

 

[custom442]

I would use a 110 gph one so you don't need a fuel pressure regulator. Mechanical is a better idea because you know it'll work at all times. It's a good idea to also run an inline electric pump for ease of start up.

 

[will6318]

so i should run both a mechanical and electric pump? how do i do this?

 

[shotgun]

There are ways to run both but a doubt you need it.

Street car? Race car? Horsepower?

The formula I use is:

Take the pumps rating at the pressure you are running x4 for a deadhead system or x5 for a return style system.

My pump is a Comp 140 free flow, it is rated at 125 at 7 psi.

125 x 5 ( I run a return) = 625 hp

On the dyno she made 630hp and I have yet to have a fuel issue running 10 flat @ 130mph.

Free flow numbers that they like to use to sell pumps mean nothing, find it's rating at the psi you plan to run and go from there.

 

[Hippi]

ok gph has nothing to do with needing a regulator,psi is where the regulator comes in for a carb 5 to 9 psi is the range you run in.Forget about running both one or the other will do just fine. As far as the stock tank you should be able to put an electric pump inline close to the tank and a regulator in the engine compartment,Now that being said a good mechanical pump will feed a holey just fine.So it's up to you running a electric pump will be more work and cash than just putting a good mechanical pump in.

 

[custom442]

ok gph has nothing to do with needing a regulator,psi is where the regulator comes in for a carb 5 to 9 psi is the range you run in.Forget about running both one or the other will do just fine. As far as the stock tank you should be able to put an electric pump inline close to the tank and a regulator in the engine compartment,Now that being said a good mechanical pump will feed a holey just fine.So it's up to you running a electric pump will be more work and cash than just putting a good mechanical pump in.

Any pump above 110 gph generally flows above 7 or 8 psi. Check it on any pump above 110 gph you buy, I'll bet it flows above 8 psi unless it can shut off automatically at a certain point.

... to another post, 140 gph is too much. It will flow at a higher pressure and is too much for your application. I'm guessing you don't have over 550 hp?

 

[custom442]

so i should run both a mechanical and electric pump? how do i do this?

Just bolt the mechanical one on the block, that's your primary fuel pump.

You can use the electric pump inline, bolt it under the car if you wish, to use as an auxillary. The only reason you would even use an electric pump is to push fuel to the carburetor before start-up. The mechanical vs electrical doesn't save enough power to matter, unless this is some crazy hp drag car. This is a VERY good idea for those of you who've never done it. Especially if the car isn't a daily driver... after letting the car sit a month or two (or longer), charge up the battery and turn on the electric pump till it the 'clicking' noise. Fire it right up every time.

Call the company who makes the electric pump and ask them if it's suitable for this type of application. I've used an 80 gph electric pump downline from a 110 gph mechanical one without affecting free flow, but all pumps aren't made equal. Better to check before buying.

 

[shotgun]

'... to another post, 140 gph is too much. It will flow at a higher pressure and is too much for your application. I'm guessing you don't have over 550 hp?'

I assume that was aimed at my responce.I am not suggesting HE use a 140, it was just an example.

None of us can really give "good" advice without more info from the OP.

On a side note, Carter are the only pump that I know that allows free flow threw it when off.

Back, way back, in the day they sold a trak-pak which was a inline pump.

Years later we put a carter back at the tank inline, it was wired to the n2o arming switch. We put a T fitting where the hard line turns to rubber right near the d/s footwell (A-body). The one side went to the mech pump and the other went to a n2o solenoid.

Worked well for someone who did not know what they were doing!! Maybe we just got lucky, never hurt the motor running a 150 shot.