The Stovebolt Site Forums The Shop Area Engine Shop Fuel Line - What Size ? - Starve ?

My 1938 Chevy 1/2 ton is now somewhat driveable. One issue I've noticed is that I think it's starving if I need to accelerate for more than about 20 sec.

I'm suspicious of the fuel line from the tank to the pump. What's on the truck is copper plumbing flex line (with a new "correct" rubber hose actually connecting the copper tube to the tank). This copper tube is connected with standard hardware-store compression fittings at both ends, but the ID of this copper seems awfully small. Engine is a 216, and the fuel pump is apparently one of those with the built in vacuum pump.

What's supposed to be there between the tank and the pump ? Is this the likely culprit for a starve problem ?

Thanks !

Alex Meade

I think your fuel line should be 5/16 inch steel tubing. You could also have a bottleneck at the tank outlet where scale, varnish, rust, and crud tends to cluster. A good test: Rock the truck from side to side to spread around the imagined junk. If this results in improved performance, time to pull and boil out the fuel tank. Do you have a good inline fuel filter? That, plus a new fuel line (copper is not a safe material), and a tank boilout would help a lot. Find a local radiator shop that does fuel tanks, it is a good investment.

while you are at the radiator shop, ask about getting the tank coated on the inside. that ends one problem. seems like i remember most fuel lines were 3/8 steel. i would lose the copper.