i have just pulled out my fuel tank to have a good look at sizes of lines and such. my fuel setup will consist of somewhat of the following:
5/16" hose from tank to Carter Black lift pump (with filter in between), 5/16" hose from lift pump to surge tank, 1/2" hose to bosch 044 (with filter in between), 5/16" (bundy tube or similar) to fuel rail, 5/16" (bundy tube or similar, after pressure reg.)return to surge, 1/4" hose return to fuel expansion chamber (in side of ute), 1/4" hose back to fuel tank.
my question is because the fuel line from the tank (feeding surge tank) is only 1/4" should i replace it entirely OR can i get away with just using 1/4" hose to filter/lift pump then use 5/16" from outlet of lift pump to surge (if i get the right fittings.) or will this 'starve' the lift pump.
what have other people done.
keep in mind i have everything i need to do the fuel system and do not want to use a different tank.
hope this isnt too confusing
Thanks again
Tom

On a street car, I reckon you'd survive with the 1/4 feed to the surge tank if you were running a surge tank. Hell I used to run my Bosch (VL Commodore) external EFI pump through a coil ballast resistor most of the time to keep the pump cool in summer. If it's a race car.. run 5/16ths.

For 5/16th from fuel tank, you are going to need to put in new lines by silver soldering in a new plate where the factory one goes. It's reasonable that you do that. I wouldnt recommend using 1/4 inch return lines at all. I would recommend using 5/16th return line, because at idle almost all of the fuel goes back to the tank. Otherwise if you get some back-pressure, the fuel pressures at the rail may get too high at idle, and will result in over rich and stalling at the lights, which is no good for a street car.

For my sedan:
I have run 5/16th all over.
I have a welded in swirl pot and walbro EFI pump and use a Magna wagon intank pump bracket.

I do get a small fuel leak through the spot welds that hold the swirlpot in the base of the tank, but after a couple of minutes driving it's not noticable.

I run 5/16 all Through, only one which is bigger apprx 13mm is at the outlet of the surge tank... To the Bosch o70 pump

Sorry to butt in, but I'm at this point with Sr20de convo. So are you guys saying i shouldnt use my existing fuel line as a return line ?

instead of mucking around with 2 expensive pumps and a surge why not try this http://www.ozdat.com/forum/viewtopic.php?f=8&t=7070 then you done have to worrie about feed sizes, its cheaper, neater and quiter

The return on my surge tank is already 1/4 so that cant be changed now so I'll just hope it will be OK (if i do get trouble i can always replace that later on). So i guess the answer to my main question is to remove the 1/4" feed line from ther tank and get a 5/16" one, can i just find a 5/16" line at the wreckers, and more to the point what cars come with 5/16" that can be easily fitted into the datto tank...
also what exactly does the fuel expansion chamber do?

Any advice on my last post?

you can go buy the fuel line for a couple of dollars a metre. or pretty much any fuel injected car will have 5/16th fuel line

Do I need to keep the fuel expansion chamber or can I just get rid of it?

You should be fine with 1/4" tube in low pressure sections, you will need 5/16 in high pressure sections:

therefore, tank to surge can be 1/4 no worries
from fuel pressure regulator (on fuel rail) back to tank is low pressure also so can be 1/4

the only place that needs to be 5/16 is from the outlet of your high pressure pump to the fuel rail (including through any filters along the way)

reason:
high pressure in a small fuel line over a decent distance results in significant pressure drop
low pressure in a small fuel line will not reduce in flow anywhere near as significantly (in fact it just flows faster than it would in a bigger pipe)

on the subject of filters, typically you would have one before the high pressure pump so that it doesnt get damaged and one after the high pressure pump so that if the pump does wear/get damaged nothing damaging gets to the injectors