Fuel return line - yes or no??

[chargerfreak]

While I try and get some answers on the electrical bugs I've got I'm going to start my next big project: replacing my fuel system. My lines are old and clogged and my tank is pretty shot. I've got a 20 gallon cell for the trunk an am going to use an electric fuel pump. My friend gave me a brand new Barry Grant 220 for free. On the Barry Grant website they show a plumbing diagram that includes a return line from the carb. Is this necessary? I was at the March Meet (Drags) this last weekend and I couldn't find a single car with a return line. I looked at Mopars, and those "other" brands and not a one. Blown, injected, naturally asperiated, none of 'em. Are these people just blowing it or is the Barry Grant set-up overkill.
Thanks

[pishta]

Some pumps are not regulating for their max PSI. In this instance, you would run a fuel log with a "pill" or some other valve in it so it diverts the excess fuel pressure back to the tank. This is common in older fuel injection setups. if you were to run a high pressure pump without a return line, it might blow the needles right off the seats and flood the carb, no where for the gas to go!! That is why you see some fuel logs on a duel inlet carb with an additional port on the back. It is for the return line.

[70Barracuda]

Is it an 220HR? Yes? It needs a -8 to the carb and a -10 back.

[dirty dan]

Originally posted by pishta
Some pumps are not regulating for their max PSI. In this instance, you would run a fuel log with a "pill" or some other valve in it so it diverts the excess fuel pressure back to the tank. This is common in older fuel injection setups. if you were to run a high pressure pump without a return line, it might blow the needles right off the seats and flood the carb, no where for the gas to go!! That is why you see some fuel logs on a duel inlet carb with an additional port on the back. It is for the return line.

I don't know the spec's on your grant pump.
But Pishta is right on target.
with accurate advise.

[Slingshot383]

chargerfreak, any injected engine running a cam or belt driven pump has returns on the fuel system. Now you can plumb the returns into your feed line between the tank and pump if you do it correctly and a lot of people do that to save weight of all that braided line. You will have a shutoff return, and a main return that has a jet can in it. Then you can also have a high speed and an idle return on an injection system.

As far as electrical fuel pumps, a system with a fuel log and a return is easier on your pump and keeps the fuel cooler and reacts quicker to the needs of the engine. It's not a "must have" with a lot of electric fuel pumps, but it is really the correct way to plumb a racing fuel system.

[chargerfreak]

Thanks to everyone for the feedback. After reading all of your responses I'll definitely be using the plumbing diagram on the Barry Grant site.