Morning! In my quest to make my 1950 Pontiac my daily driver I'm trying to get ahead of things if I can. With that said I'm curious about adding a fuel return line so... Should I go with a filter with the return or a pump with a return. They are both readily available. I just wanna prevent vapor lock if possible. I will be driving it most everyday and have a/c installed for these hot summers. Thanks !!
I’ve got one of these return style filters right before the carb. Also a nylon spacer under the carb.
Without knowing what the entire fuel system comprises of, a couple of ***umptions- running a carburetor with some kind of in-line fuel pump? Typically, vapor lock is caused by fuel "vaporizing" (boiling) in the carburetor or in the near fuel line due to heat. A phenolic spacer under the carburetor will help. If planning a return line, having it close to the carb inlet would be the best as long as you have adequate fuel pressure.
If you have a stock gas tank, or a reproduction gas tank, that has the small diameter supply tube...your trouble starts there. I purchased a Reproduction gas tank once and the supply line was for a six cylinder. It was a Bottle-Neck right out of the gate.
Adding a fuel return is a good idea. Having it return from the filter gives you a little benefit over returning from the pump, but they both help. Although neither will keep the carb itself from boiling fuel out...if you have room for a thick insulating carb spacer, put one in.
An electric fuel pump used with a return line from the engine compartment will provide the best way to furnish cool fuel. That way the fuel does not sit still in the fuel line, but constantly is in a flowing motion and returning if not used. Late model cars get away with making a return at the fuel filter under the car and near the back. This saves the factory the cost of a long return line. It works on them because they operate at higher pressures and use fuel injection. Without the higher pressure and injection, you still have fuel sitting or not moving very fast all along the fuel line. Thats the difference from my viewpoint.
Thanks for the replies guys. So a little more on the fuel system. It's a stock pontiac mechanical fuel pump. Stock plumbing from the original fuel tank. I cleaned and sealed the tank. Also I've installed a new sending unit with a new "sock". I have put about 1500 miles on the car so far without any issues. I'm just thinking ahead. I can drill the tank and add a return or maybe return thru the drain??? That's why I was wondering if pump or filter was better because it's easy for me to go either way right now. Also I do have a phenolic spacer under the carb.
I've also thought of going with an electric pump. If I did what is considered a reliable/daily driver electric pump?? Thanks again
It kind of depends on how deep you want to get into doing the conversion. There are aftermarket fuel pups which are externally mounted but you would still have to find a way to make a return to the tank....ie: modify the tank. If you go with an intank pump, which is best (IMHO), I'd contact "Tanks" and see if they have a unit that may fit your existing tank or a complete tank with the correct pump set up. Myself, I like OEM pumps and tanks for most conversions, but I have never done a 50 Pontiac and also don't know if you have the tools and stuff to cut a tank open and weld an OEM Pump's tank hole into your tank. The older 80s S-10 pickups had low pressure pumps. Once done though, you have a pretty reliable set-up.
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