Fuel Question

[Andreasu]

I'm running a holley blue-pump and regulator in my car (soon) and does it need an return fuel line to not overflow the carb? Also gonna run a 16 gall. fuel cell (http://www.summitracing.com/parts/SUM-290100/)



If I need a return line, how do I "plumb" that? Before regulator, in the regulator or after?

[NOT A TA]

I run one dead head without a return line. It will not overflow the carb if you have a pressure regulator. I've read that the return line will help the pump to live longer.

[Andreasu]

I run one dead head without a return line. It will not overflow the carb if you have a pressure regulator. I've read that the return line will help the pump to live longer.

But, where do I plumb the return line?

[Windycity1]

You dont need a return line with a holley blue pump.

[Andreasu]

Thanks : )

Just plug the return-line on the fuel cell then?

[Vegas69]

It depends on the application. In a high horse application that will see many full throttle runs, I want to see a return. Your pump is running at full bore all the time and there is no delay in fuel volume when you decide to mash the gas.

[Andreasu]

Still, "where" do I plumb or fit the return line? : p

[Vegas69]

You need a return style regulator and return the fuel in the top of the tank.

[Andreasu]

With 300-400 hp, would I need a return line?

[Vegas69]

I'd call Holley.

[Andreasu]

Thanks for the help

[gabe74gt]

Nice info. I am going to do

[67 455 Bird ragtop]

It depends on the application. In a high horse application that will see many full throttle runs, I want to see a return. Your pump is running at full bore all the time and there is no delay in fuel volume when you decide to mash the gas.

Reviving an old thread since I'm about to start plumbing my fuel system.

So, for say a 470 c.i. car making in the 500-550 hp range that ia mainly street driven in Florida a rerturn line is not reaaly needed?? I don't think I ran one on my previous motor either. I guess if I have any heat related vapor lock issues I could always add a return line later since I have already purchased a return style regulator. I can plug the return now and see how things go. Or should I just go a head and plumb a return line now??

Are there any negative effects to using a return line on a carberated motor?? I'll be running a ProComp PC-2803 "Black" fuel pump with a Mallory 4309 regulator.

[Vegas69]

A return system is always preferable. I realize it's a little more work but you'll sleep well at night knowing your fuel system will be bullet proof in ALL conditions.

[Norwood]

A return system is always preferable. I realize it's a little more work but you'll sleep well at night knowing your fuel system will be bullet proof in ALL conditions.

+1 Taking Murphy's Law in consideration and when and where you may experience a vapor lock, I'd put the time and effort into the project now in a controlled environment. It's just cheap insurance.

[67 455 Bird ragtop]

Points taken. And I also believe the rule is return same or even one size bigger than the supply line. And the same for the fuel cell vent.

[wmhjr]

Actually there is another method tonimproventhings a little in a carb motor with a deadhead regulator. It's not really designed to prevent the carb from overflowing - more for vapor issues in a high HP application. I've mainly heard it called a "piss valve". Robbmc sells a fitting, or you could drill an orifice yourself in a fitting. Effectively, you place a small bore bleeder orifice (iirc, about 7 thous) between the regulator and the carb, and that goes back to the tank vent. I'm running that setup. It's not common

[MonzaRacer]

Just use a good brand of return style regulator and your good, on most cars using the old evap vent tube works well.