fuel line size?

M

mainiac239

Member
47 ford truck , looks like 1/4" fuel line between stock pump and carb
would it have any negative effects if i upgraded to 5/16 line?

having problems with vapor lock so this is the new set up im going to try -
out of the tank through 5/16 fuel hose to in line filter and through electric fuel pump ( 2-3psi), 5/16 fuel hose to stock pump then 5/16 hard fuel line to carb

im using fuel hose instead of hard line from tank to stock pump because i thought it would insulate the fuel better than metal fuel line


comments?
 
A larger fuel hose won't help. The needle valve has an orfice of about .100 so more fuel sitting in a larger line will just get hotter. Above 52 MPH on a 95 degree day there is no boiling problem because enough fuel is being used and more fuel flowing through the line cooling the line and other parts. A fuel return after the pump will probly do the best job of cooling but I never wanted to add a return line. Even with a return you still have to deal with the carb which is heated by the intake manifold. This can be prevented by a 1/2" vented spacer from gadgiteer@aol.com that comes with gaskets and longer studs. Along with the spacer you need to reduce the heat riser holes from .625 to .325 This will cool the carb. G.M.
 
Stick with using the 1/4 in. fuel line. 5/16 won't make any difference. Use a spacer under your carb.
 
Don't go with rubber hose the length of the chassis. Use as little of rubber hose as possible. Metal tubing will last a lot longer and is safer than all that rubber hose. Rubber hose can deteriote much faster than metal, especially with the ethanol fuels.

If you want to insulate the tubing, slit some rubber hose and put it over the metal tubing.

If you are using an electric fuel pump, you shouldn't have a problem with vapor lock. Put the electric pump as close to the gas tank as possible. They should push, rather the pull.
 
There is also the possibility of putting 1/4 line inside a 3/8 hose and use it for insulation. This could do wonders for the vapor lock problem under the body. I have used 5/16 fuel line hose from front to back with no problem sooooo far.
 
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