install fuel regulator before or after pump?

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tiltedsix

tiltedsix

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hello,out there ....69 Dart 225 - should I put the fuel regulator before or after the fuel pump? ....and for the feed back to tank?? do I have tap the tank towards top & install fitting.....or can I put a 3 way in-between fuel Mod line & metal fuel line or maybe to gas tank refilling tub in trunk....thanks for looking
 
You want to regulate the fuel pressure going into the carb.. so after the pump and before the carb.
 
It actually works best installed after the carburetor and regulating on the return side, using the regulator as the return orifice.

Like this:
 

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RustyRatRod said:
It actually works best installed after the carburetor and regulating on the return side, using the regulator as the return orifice.

Like this:
Click to expand...

wouldnt this set up let the carb see full pump pressure? say if your pump was pushing 11 lbs.
 
younggun2.0 said:
wouldnt this set up let the carb see full pump pressure? say if your pump was pushing 11 lbs.
Click to expand...

No. The regulator can be anywhere in the system and it will regulate fuel pressure.
 
tiltedsix said:
hello,out there ....69 Dart 225 - should I put the fuel regulator before or after the fuel pump? ....and for the feed back to tank?? do I have tap the tank towards top & install fitting.....or can I put a 3 way in-between fuel Mod line & metal fuel line or maybe to gas tank refilling tub in trunk....thanks for looking
Click to expand...

Why do you think you need a pressure regulator? What fuel pump? What type of pressure regulatorn are you considering, a "deadhead", or return flow? It will make a difference in the plumbing. A "Deadhead" regulator, needs to be installed between the pump outlet and the carb, as near the carb as practicable. A return flow regulator also needs to be after the fuel pump, but can be located anywhere after the carb as per RRR diagram, and requires a return line back to the tank.
 
The regulator does need to be before the carb. Regulators regulate lower the pressure going out of it so after the carb as suggested above would mean full pump delivery pressure to the carb. Some of this stuff is just common sense.
It wont be easy to get a return line to dump low in the tank but that is the best place for it. Less aeration in the fuel means more dense fuel.
 
Some stuff IS just common sense. That's a return type regulator in the diagram above. As Charlie noted they can be used anywhere in the system and will regulate fuel flow. They are designed however, to be used in the return line. They WILL regulate fuel pressure that the carburetor sees. That's the only type regulator I have ever run. That diagram btw, came from the Barry Grant site. Holley, Mallory and all the rest have similar diagrams using return style regulators. Are you say they're doin it wrong?
 
Yes that regulates line pressure by relieving the excess. I'll bet a quarter that gauges at each carb entrance will differ and bounce much more than if it was pre carb.
It does have one advantage... A before carb regulator might reduce volume depending on size of the passages inside it. Per the diagram, volume is restricted only by fuel line size.
 
RustyRatRod said:
Some stuff IS just common sense. That's a return type regulator in the diagram above. As Charlie noted they can be used anywhere in the system and will regulate fuel flow. They are designed however, to be used in the return line. They WILL regulate fuel pressure that the carburetor sees. That's the only type regulator I have ever run. That diagram btw, came from the Barry Grant site. Holley, Mallory and all the rest have similar diagrams using return style regulators. Are you say they're doin it wrong?
Click to expand...
Technically it's not really "after the carb" which is where people are getting confused. What it does is bleed off the excess pressure from the fuel line making it more of a fuel rail like in an injected motor. The fuel pressure is still regulated before the carb. The biggest difference is that it uses a return line. Some guys just use a regulator on the fuel line before the carb w/ no return & the regulator just restricts the pressure going into the carb.
It's actually a more acurate way to have equal pressure to both float bowls than w/ the regulator before the feed lines to the bowls.
 
Rustyratrod is 100 % correct this is the way to do it with the new ethanol pump gas. This keeps the fuel moving and doesn;t allow it to dead end at carb. The new fuel boils and causes flooding when hot when dead ended.
RustyRatRod said:
It actually works best installed after the carburetor and regulating on the return side, using the regulator as the return orifice.

Like this:
Click to expand...
 
Lonewolf3165 said:
Technically it's not really "after the carb" which is where people are getting confused. What it does is bleed off the excess pressure from the fuel line making it more of a fuel rail like in an injected motor. The fuel pressure is still regulated before the carb. The biggest difference is that it uses a return line. Some guys just use a regulator on the fuel line before the carb w/ no return & the regulator just restricts the pressure going into the carb.
It's actually a more acurate way to have equal pressure to both float bowls than w/ the regulator before the feed lines to the bowls.
Click to expand...

RIGHT! sorry for the confusion there. All I meant by "after" the carburetor is simply the regulator is placed in the return. I think you seem to have gotten that. lol
 
Oldmanmopar said:
Rustyratrod is 100 % correct this is the way to do it with the new ethanol pump gas. This keeps the fuel moving and doesn;t allow it to dead end at carb. The new fuel boils and causes flooding when hot when dead ended.
Click to expand...

Exactly so. You can approach throttle body injection drivability plumbing a fuel system like that. It works good.
 
so I should have specified my carb is a Holly 1bbl it only has 1 in-port '69 Dart 225 and I did order the regulator with blow back.....thank you guys for all the feedback :usa2:
 
hello rusty,....im doing because out of the blue 2 weeks ago started heavy fuel dumping in carb..new holly# 1920 1bbl(had been running fine)trying to pinpoint problem I replaced fuel pump, new hoses, filter ,lowered float a lot ,needs clean and moves freely ,can t get to run long enough to check pressure...it floods so quick & is done for day...trying to be crafty I put a cut-off valve to try manually control..helped but not well enough probably silly anyway... smile....put old carb same problem ....Oregon coast ....vapor lock maybe
 
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