EFI pump regulated to carb?

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EFI pump regulated to carb?

Postby 77cruiser » Fri Aug 18, 2017 6:46 am

I want to try an EFI in tank pump. Not sure on the regulator.
I have an Edlebrock 174133 & when trying it with air it doesn't regulate down far enough, it will go to about 14 from 90.
Would it be different with fuel or would I get the same results?

https://www.summitracing.com/parts/edl-174133
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Re: EFI pump regulated to carb?

Postby cjperformance » Fri Aug 18, 2017 6:59 am

What is the flow rating on your pump?
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Re: EFI pump regulated to carb?

Postby Belgian1979 » Fri Aug 18, 2017 7:12 am

Even if you could get it regulated way down to the required fuel pressure of 6 - 7 psi, the efi pump is way overkill and would heat up your fuel substantially due to the constant pressurizing of fuel and sending it back into the fuel tank.

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Re: EFI pump regulated to carb?

Postby 77cruiser » Fri Aug 18, 2017 7:13 am

320 LPH so 84 gal. p hr.
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Re: EFI pump regulated to carb?

Postby joe 90 » Fri Aug 18, 2017 9:29 am

It all depends on how you do it.

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Re: EFI pump regulated to carb?

Postby 77cruiser » Fri Aug 18, 2017 10:13 am

joe 90 wrote:It all depends on how you do it.

As in.
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Re: EFI pump regulated to carb?

Postby Circlotron » Fri Aug 18, 2017 5:15 pm

Belgian1979 wrote:Even if you could get it regulated way down to the required fuel pressure of 6 - 7 psi, the efi pump is way overkill and would heat up your fuel substantially due to the constant pressurizing of fuel and sending it back into the fuel tank.

Except for the reg pressure setting, isn't that exactly the way the pump operates in an EFI situation? In fact, seeing the reg would be set at a much lower pressure for a carb, the pump wouldn't be working against much of a head at all so it wouldn't be supplying as much power and ultimately heat into the fuel as it would in an EFI setup. Lots and lots of flow though.

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Re: EFI pump regulated to carb?

Postby 77cruiser » Fri Aug 18, 2017 7:38 pm

Circlotron wrote:
Belgian1979 wrote:Even if you could get it regulated way down to the required fuel pressure of 6 - 7 psi, the efi pump is way overkill and would heat up your fuel substantially due to the constant pressurizing of fuel and sending it back into the fuel tank.

Except for the reg pressure setting, isn't that exactly the way the pump operates in an EFI situation? In fact, seeing the reg would be set at a much lower pressure for a carb, the pump wouldn't be working against much of a head at all so it wouldn't be supplying as much power and ultimately heat into the fuel as it would in an EFI setup. Lots and lots of flow though.



That was my thought.
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Re: EFI pump regulated to carb?

Postby joe 90 » Fri Aug 18, 2017 8:01 pm

As a bare minimum , you start with the pump, an EFI type regulator and a return line back to the tank.
Then from that primary pressure,(2 bar ish as a minimum) )you can regulate it down using a carburetor type regulator to the carburettor.

Even a 255 litre/hr pump will outflow most EFI regulators so you need either a very high flow reg (or multiple FPRs), or better still you use a 2 stage switch for the pump using a resistor.Most aftermarket FPRs are adjustable so you can turn the pressure down to minimum.
Better still you can go for a PWM drive for the pump.


But if you're going to that trouble, you'd want to get rid of the carburettor too?


But there's always more than one way to do everything.

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Re: EFI pump regulated to carb?

Postby Belgian1979 » Sat Aug 19, 2017 1:35 pm

Circlotron wrote:
Belgian1979 wrote:Even if you could get it regulated way down to the required fuel pressure of 6 - 7 psi, the efi pump is way overkill and would heat up your fuel substantially due to the constant pressurizing of fuel and sending it back into the fuel tank.

Except for the reg pressure setting, isn't that exactly the way the pump operates in an EFI situation? In fact, seeing the reg would be set at a much lower pressure for a carb, the pump wouldn't be working against much of a head at all so it wouldn't be supplying as much power and ultimately heat into the fuel as it would in an EFI setup. Lots and lots of flow though.


You're better off using pwm to adjust the pump flow.

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Re: EFI pump regulated to carb?

Postby FuelieNova » Sat Aug 19, 2017 2:02 pm

I used my EFI fuel system to run a carb for two years when I got mad at Fast and swore off EFI for a while.
I had the Aeromotive 340 pump and regulator. Just swapped springs in the regulator AND I have to use a 1/2" return line to get the pressure down to a consistent 6psi.
If you are really serious you could get a pump controller setup that uses a pressure sensor in the fuel line and set the amount of pressure you want, it will slow the pump down to maintain your pressure set point. Vaporworx has a setup like this.
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Re: EFI pump regulated to carb?

Postby Belgian1979 » Sat Aug 19, 2017 3:07 pm

any efi unit will be able to put out a pwm signal. Use a Ford FPDM an your set for around 50 bucks. Fool proof. I use one in order to reduce the pump speed because it makes too much noise at low engine speeds and heats up the fuel considerably. Of course in a efi setup, you would be circulating fuel through the fuel logs that are mounted on the engine. That in itself heats up fuel enough.

If you use a pwm control, you have to either use it in closed loop with a dead head system or in open loop with a return style system. Closed loop and return style do not work and the regulator and closed loop control will be fighting eachother.

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Re: EFI pump regulated to carb?

Postby cjperformance » Sun Aug 20, 2017 2:04 am

FuelieNova wrote:I used my EFI fuel system to run a carb for two years when I got mad at Fast and swore off EFI for a while.
I had the Aeromotive 340 pump and regulator. Just swapped springs in the regulator AND I have to use a 1/2" return line to get the pressure down to a consistent 6psi.
If you are really serious you could get a pump controller setup that uses a pressure sensor in the fuel line and set the amount of pressure you want, it will slow the pump down to maintain your pressure set point. Vaporworx has a setup like this.
Tom



↑↑↑ yes,, you need a very low restriction return line otherwise and pressure seen in the return will affect pressure at the carb. Depending on how many bends etc, sometimes you need a return line larger than the feed line to get accurate control at the carb.
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Re: EFI pump regulated to carb?

Postby modok » Sun Aug 20, 2017 4:02 am

joe 90 wrote:As a bare minimum , you start with the pump, an EFI type regulator and a return line back to the tank.
Then from that primary pressure,(2 bar ish as a minimum) )you can regulate it down using a carburetor type regulator to the carburettor.

Even a 255 litre/hr pump will outflow most EFI regulators so you need either a very high flow reg (or multiple FPRs), or better still you use a 2 stage switch for the pump using a resistor.Most aftermarket FPRs are adjustable so you can turn the pressure down to minimum.
Better still you can go for a PWM drive for the pump.


But if you're going to that trouble, you'd want to get rid of the carburettor too?


But there's always more than one way to do everything.


Good answer!
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Re: EFI pump regulated to carb?

Postby hondo383 » Sun Aug 20, 2017 2:59 pm

What size is your return line/any restrictions to the tank?that reg should be fine but the return line capacity to the tank has to be equal or greater than the feed line capacity..i use a Mallory 4309 usually and have to put a bulkhead and tube in the tank for return. For a test just put a bigger hose on the return and dump it into a bucket, see if you can get the pressure down further

Edit yall above beat me to it lol


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