Working on a 1969 455 engine. Has some modifications, so originality is not a concern. The fuel pump is done. My search results on line are a fuel pump with a vapor return line. The fuel pump on the engine does not have a vapor return line. Nor does it have a fuel filter with a vapor return line. My goal is to use a mechanical pump and fuel filter with a vapor return line. Does that make sense? I have an Edelbrock carburetor which according to edelbrock runs best with 6.5 PSI fuel preassure. I willl be using a preassure regulator.
My questions,
Am I on the right track?
What pump and filter should I use.
Any help is appreciated.
Thank You,

 

First, fuel return is not a vapor line, it is intended to recycle a small amount of the liquid fuel back to the tank as a way to help mitigate vapor lock. Olds used fuel return on cars that were likely to have higher underhood temps, predominantly those with A/C or higher performance engines. The vapor line from the tank to the charcoal canister runs directly from the tank to the canister and has nothing to do with the pump. It also wasn't used on 1969 cars. Many 1970-up cars came with both fuel return AND vapor lines.

As for your pump, the important question is, does the CAR have a fuel return line plumbed to the gas tank? If not, keep the pump you have. If it does, get a pump with a return line fitting.

 

Joe, thank you for the replie.
Very interesting. Even Summit told me what I need is a pump with a return line. So, I purchased and installed a pump and a new vented fuel tank with a return line.
I guess it wont hurt to connect them up?

 

FYI, Summit is not a reliable source of parts applications for Oldsmobiles.

 

I recently installed a Carter "muscle car" fuel pump in my '69. The car originally had A/C and big block so is factory plumbed with a return line. I like the pump but it's not "original" in the sense that the high pressure outlet orientation is different than a 'stock' '69 442. Doesn't matter to me. I have a QFT 4150 style carb installed which also doesn't want more than ~6.5psi. so I had to plumb in a regulator. I've run an Earl's in-line filter between the pump and the carb for several years and am happy with it.

 

acavagnaro, thanks for thae post. Do you have the return line plugged? You mention 6.5 psi. As far as I know the "muscle car" fuel pump is rated for 6 psi. With the return line plugged I am getting a reading of 11 psi. I will be installing a preassure rehulator, and a return line to the tank.
I wonder what the proes and cons are for running a these pumps with a preassure regulator and the return line plogged. Just want to buy some time and install the return line over the winter.

 

No, I do not have the return line plugged. The return line on the pump plumbs into my original return line (I believe 5/16"). 3/8" fuel comes into the pump in the stock configuration (hose). I plumbed the pump high pressure outlet to an Aeromotive regulator which I really like. It's a 'dual outlet' type but I have one of the outlets plugged. The other outlet runs through the fuel filter and into the carb. I have a pressure gauge plumbed into the carb inlet line.
Don't believe the published pressure ratings of the pumps. I measured close to 10psi on two separate pumps that were each rated at 6psi. Holley isn't joking when they say to limit inlet pressure to 6.5psi. Anything over that and it'll flood.
You want to focus on keeping your fuel temps low. Some regulators will have a return line to the tank to avoid recirculating the fuel to the carb and raising the fuels temp. This is nice but requires a line back to the tank and a fitting plumbed in to accept it. The regulator I use does not have the return line but no problems so far with excessive fuel temps at the carb. If I were you and planning to add a return line back to your tank, I'd use it for the regulator and not the pump.

 

acavagnaro,
good information, thanks.
Have you considered a fuel filter with a built in return line?

 

No. I wanted to avoid having to run a 3rd line front-to-back and then plumb another return into the tank.

 

FYI: my 66 442 has a return line. It goes straight to the tank, no charcoal canister.

 

Evaporative control emissions systems didn't exist until mid-1970 on Calif cars and 1971 on 49 state cars. The return line is completely unrelated from evaporative control systems.