I have to drain and drop the gas tank so I can drill into the rear frame rail and re-mount my electric fuel pump. I currently just have a 6" piece of hose with a fuel filter at the top as a vent...I have a fuel regulator about 24" before the carb (see pic below). Several questions... 1) would I see any benefit from a return line? --I wonder if it will cut down on "cavitation" noise from the fuel pump. 2) where would the return line start from? --I assume the plugged hole in my regulator or closer to the carb inlet? 3) can I run it back into the vent tube in the top of the tank? 4) will I have to re-adjust the fuel regulator or will the return line not affect overall fuel pressure? 5) would I need to use a vented cap afterwards? Anything else I should know?
Ask Frank. He just put in an EFI and, I think, he had to do a return line. He may have talked about it when he posted about the EFI.
Couple more questions... would I need it on a carbureted car, and does the return line have to be as big as the main fuel line? Maybe Frank will get on later and give me some help here....
If your run an electric fuel pump with a fuel regulator you absolutely need one IMO. If you dont run one you are putting a much greater strain on your pump and run the risk of overheating it due to it trying to pump gas to the carb and cant because of the regulator. Thats just my though.
Scott you will need to use a bypass regulator or bypass style fuel log. A bypass system will let the pump run cooler and likely quieter and provide more consistent fuel pressure.
1) yes, It will quiten the pump, The pump will no longer be dead headed. 2) It starts from the return regulator, You must use a RETURN REGULATOR. Or fuel log. 3) Yes thats where mine is ran to, although you must modify the inside of the vent, You also need to make the hole the same size or bigger than your supply line. Run the same size return line as the supply. 4)After you adjust the RETURN style regulator there will be no futher adjustments. 5) Yes or just vent yours. Now just my 2 cents, it will take a load off the pump and electrical system, The fuel will run cooler, And when you put octane boost in the tank it will mix fast. Also when you install the Nitrous kit you wont have the rich surge when the nitrous comes on.
The tank is out for easier access to the frame rails while I remount my fuel pump... Here is the regulator I have...notice it has the fuel coming in from the bottom, going out through the side with the braided hose, and then has the right side plugged. Do I run the return line through the plug? I guess what I am asking is, is this a return regulator?
Never mind...I looked up "bypass regulators" and if you didn't pay $150+, you don't have a bypass regulator. I will just hook everything back up tomorrow and use it as it is for a while longer. So, can I at least hook up a pressure gauge on that second outlet?
Yes you can run your pressure gauge to the other side. Or you can buy a fitting that goes in-line that has a 1/8" port built in.
Your pump will be quieter. And it wont bang on the regulator when you hit the key(deadheading)You wont get that RRRRR-thud sound.By-pass regulators.Yes they are cha ching expensive but well worth it IMHO.When you do do it, Put a bung on the tank to mount your return line to.If you can get a bung that you can attach a stand-pipe to on the inside of the tank.Set the stand pipe depth so it ends about 2 inches off the bottom of the tank.Reason being the fuel returning to the tank wont splash and agitate causing aireation of the fuel in the tank.This can cause cavitation in the pump/pickup depending on how close the return is to the pickup.(put it as far from the pickup as you can)Just something to consider when you do it.
I will just wait until I have the cash to do it right...I need to replace all my steel lines with braided stainless, and swap all the hoseclamps out to AN, so I will do this all at one time. Status quo for the time being... Thanks for all the help. I was hoping I could do it with what I have...
I'm not trying to ruin your day, ( But) If that is one of the Holley Regulators that comes with the pumps, Or you can buy for 19.95. ( probably higher now haven't had any reason to check in years) This regulator is not any good for anything more than stock, Reason being, The orifice in the regulator is not large enough to supply enough (volume) of fuel to the motor. I cant remember the actual size of the orifice, But it seals with a bb. I among others years ago chased a lean condition which was traced to this regulator. I only used one for my nitrous system, (it wont supply enough fuel for a 150 shot of nitrous if this tells you anything) Others weren't so lucky they tried them on the motor. I just thought this might be info you could use, Don't want a fellow Mavericker to melt down. Remember pressure is a measurement of restriction. Not flow. I did look up the part # its the 12-803 or 12-704 in summit.P.S. I know there is a lot of lucky people out there that has ran this regulator I'm sure we will hear from. But this is not hear say I have witnessed this personally. All regulators ARE NOT created equal
That is the fuel regulator that came with my Holley Blue. It has seemed to work well, but now that you mention it, I have constantly had a sputter at full throttle I haven't been able to track down...DOH!!! So I am getting 110 gph through my system, then 60 after the regulator??? Well, I have seen some bypass regulators for $60 or so on JEGS, are they worth a crap or should I just run it as is until I can afford to do it right and replumb the entire system?
The only regulators i can speak for personally is the Mallory Maa-4309, or the Aeromotive AEI-131-01. The mallory is in the 80-90 dollar range and should be sufficient for your application. P.S. thats 110 gallons FREE FLOW, this gets cuts dramatically when you start restricting the flow.
