Does size matter? i know if u want a lot (hp) you need bigger tube, but if you make a target that line needs to handle about 500hp, what size it should be? Im going to make new lines anyway, and thinking what size it should be.
On a mechanical pump I never like to have any restriction on the inlet side of the pump. Much better to have it a little big than to small ! It will push the fuel a lot better than it will draw it.
You can have too big of a fuel line. In a drag race car with a rear mounted cell you can get into a situation where the weight of the fuel can cause the fuel to stall in the line at the launch. Just depends on how good of a pump you have and your hp requirements.
I hate to ressurect an old post like this but... If you are using factory pickups in the tank (or tanks as in the case of my project truck) , arent the outlets on these small like 5/16"? Is there someone who makes larger diameter pickup tubes to remedy this issue?
my car was a six cylinder car. i replaced the factory line with 3/8 steel. i only have one union (around the drivers side rocker) from tank to pump. i soldered a new pick up tube in the old sending unit. it was like trying to suck through a bar straw. bobn
My 460 ran OK with mech pump and original 5/16" line. the new 521 (about 500 HP) would lean out after about 5 seconds of WOTwith the mech pump and 5/16 lines. I replaced the tank with a fuel cell (-8 connections) used a black holley pump and -8 lines and all the problems went away.