What would happen if i used a non-return style regulator that had 2 outputs. like the holly 12-803? I have a buddy that hooked his up like that and I did not think that it was right. any info is appreciated. thanks

 

I think it's easy to get vapor lock without a return line. Most guys on the board recommend a return-style regulator.

 

I think he hooked his up with the one inlet and then used one outloet of the regulator to the carb then the other outlet to the return.

 

Unless the return is restricted, the pressure to the carb will be too low. I know a racer that set his up with a needle valve in the return to maintain minimum full-load pressure supply. When unloaded, the reg shuts off the excess flow.

When using a factory-type in-tank electric pump, you need a return to keep cooling flow going through the pump. Dead-heading is a no-no. The benefit of a return-style reg is it allows the pump to operate at full flow at all times - pressure is regulated by sending excess flow to the return line.

 

so a regulator with two outputs would not cause enough restriction for the carb. it has to be a return style. no a regulator with 2 outputs? thanks for all of the info.

 

A holley regulator can be used as a return style regulator but only if it is plumbed in to the fuel system properly to allow this.

 

... just a note: this system will not regulate a high pressure pump like a EFI fuel pump down to a carb friendly low fuel pressure. But will regulate a carb fuel pump without being a restriction to flow or deadheading the pump. the system will flow more fuel at high demand and the pump will last longer. The fuel will be less heated by the pump too.

 

so that setup will not work with a tbi fuel pump? I know that the tbi flows about 12psi(so I was told).

If I was to use the tbi pump I would have to buy a regulator made with a return style built into it.?

 

If you're going to use a high pressure pump then you need a return style regulator. If you have an external electric low pressure pump then you can us the two outlet ports on a 4 port regulator, one to feed each bowl.

 

i also just bought a holley blue pump(11psi) and am looking into this regulator discussion. i dont want to pay 50.00 for a bypass regulator if i dont have too. i have a mechanical stock pump now going into edelbrock 600. so this diagram will work? and whatever that guage says is what your carb is getting? anyone running like this? thanks all

 

Just add bp to the end of your part number, and it will work great.

 

regular holley regulator 17.00

same looking holley "BP" 67.00...

thanks

 

Doing something right isn't always the cheapest way.

 

Don't cheap out on a fuel system. Let it go lean once and see waht happens.

 

I have just bought a mallory 4309 regulator. I have to plumb this thing right. does anyone have a pic of one that shows where the inputs and the return and the output is? thanks

 

just installed holley blue pump and holley regulator as pictured in the link with the return line and it seems to work ok. the regulator cant flow enough fuel back to the return so the carb gets a lil over 6 psi but runs the same. can you change springs or diaphrams to flow more with these regulators?