Fuel pressure Regulator is it really needed?

[ScottFromNH]

Hi Everyone.

I have a 1973 Spitfire 1500 running a single Stromberg carb and was told I should install a fuel pressure regulator and trying to find out if this is good advice or if its not needed? Not sure what the point would be?

any thoughts.

scott

 

[TR3driver]

The main reason for installing a pressure regulator would be if you have a fuel pump that is putting out too much pressure.

That is also the only time I would consider adding one. The regulator can only work with some certain minimum pressure drop across it, so it cannot deliver the 2.5 - 4 psi that your carb wants if it is only getting 2.5 - 4 psi from the pump.

The racers like to use high capacity pumps and a pressure regulator, so they can be certain of getting enough fuel when operating at higher power (and hence higher fuel flow) than the system was designed for. Good idea for a race car, pointless for an otherwise stock setup IMO.

 

[ScottFromNH]

Thanks TR3Driver. Yeah not a racer just will be a regular road car and I just installed a new fuel pump so I should be good then

 

[TR3driver]

Well, it's not unheard-of for new pumps to (incorrectly) put out too much pressure. Are you getting any bad symptoms, like fuel running out of the carb, or black smoke from the exhaust?

 

[ScottFromNH]

oh didnt know that. No actually the engine seems to run really nice especially since the carb hasnt been rebuilt yet and it sat for 10 years. Now fuel leaking out. It idles at about 900 rpm when the chock is fully in and sounds good. I was just told by an old guy that I should put it in to help prevent problems down the road.

 

[tomshobby]

I got this one from Jegs. It has two outlet ports so I can use one for each carb.
https://www.jegs.com/i/Holley/510/12-804/10002/-1

 

[ScottFromNH]

Thanks Tomshobby its funny you send that link before I posted this I was actually looking at that one. I only have one carb and after posting this I dont think I need one

 

[Got_All_4]

If it ain't broke don't fix it!

 

[70herald]

and was told I should install a (fill in the blank)

any thoughts.

scott

Well my $0.02.... About 1/2 of what you will be told has almost no basis in fact.... the other 1/2 is probably wrong.

English carbs use a much lower fuel pressure than american designs (in general) so after people much up the original design by substituting a pump designed for american carbs, the carb will flood since the valve can't handle the higher pressure. Then they invent stories about needing a pressure regulator since they mucked up the original design.

As long as your stock fuel pump has a diaphragm which can handle modern fuel, you are all ready to go. The only thing I would consider adding is ONE fuel filter, the simple type designed for carbs.

 

[ScottFromNH]

Thanks 70herald,

I will stick with that is then already then instead of causing more issues for myself.

I actually have 2 inline fuel filters that are designed for carbs installed. One at the gas tank and then I have one between the fuel pump and carb. When I got the car it actually had 3 of them (one at the tank, one before the fuel pump, one before the carb) after talking to guys on this forum I removed the one right before the fuel pump since I had one right when the line was leaving the tank and I installed all new lines when I sealed the tank and replaced the fuel pump.