I thought it's not about saving drops of fuel, it's about minimising hidrocarbon emissions to the atmosphere.

the problem with this is when you run dry it may not lift fuel from the tank pumping air round and round in the loop you have made
otherwise all cars would be like it
a rerturn line is the only answer realy and would be handy if you ever wanted to switch to efi setup as you would have a return already fitted

in a standerd carb the inlet port for fuel has a smaller pipe tee'd off so any extra fuel pumped returns back to tank.
your only looking to feed fuel into the float chamber where it will be used at atmosperic pressure (unless your using turbo blow trough eg. metro)
so we dont need that much pressure at all realy

the ford item is designed so just fuel free of bubbles is fed to the carb and the tee off was ommited from the carb as the return was fitted to the seperator on the inner wing

:o hmmmmm decisions decisions .

eventually i,ll be fitting a zetec on bike carbs & megajolt so wouldn,t need efi or a return to the tank.
i,m trying to get the car finished asap,
i,ll try the method as mentioned & if i find its not the way forward i can always reinstall the vapour seperator.

thanks for all your help guys. :cool:

cheers
andy

One thing to remember.

Ford, and other manufacturers are tight on the purse strings. If there was no reason for them to fit it they would have left it off. IF you fit the return you can also upgrade the trap to a "Filter King" regulator filter in the future for easy preasure trimming and filter replacement.

TT

er? but the seperator would need a return line?

you cuold just pipe up direct but put in the return line later if you where pushed for time .

an idea im sure if the ford unit is to bulky for you vauxhall fitted a plastic version fitted to 8v astra's running 2e3 carbs
its mounted next to the carb on the inlet manifold

For what it's worth Andy

Personally I would just plumb up the fuel system without the vapour sepperator, I am sure the fuel pump will be more than able to regulate the fuel suply on its own.

As Ash pointed out, the inline filters will tend to sort out any vapour issues :)

From a study of my redundant, 1.8 CVH carb ( No fuel return outlet ) & a study of the ford fuel layout. The vapour sepperator is for stricter EEC emission compliance. ( Ducks for cover :D )

Penty of CVH engined cars not using a return out there mate ;)

other idea
blank out the mech pump and fit a eletric pump with a regulator if needed
you would need to go down this route if you go for bike carbs any way

you got me thinking so i read back trough some of my uni books and older car pumps i.e. pre 75 era used a spring to keep the arm one the cam and a linkage that had lost movement (elongated hole) so the diaphram could remain in positon under pressure until the cam came back around.

later on a return line was used and fuel pumps changed

3-5 psi should be about right

somthing like one of thease
http://www.rallydesign.co.uk/index.php?cPath=281_282

and one of thease
http://www.rallydesign.co.uk/index.php?cPath=281_283

Cheers Baz-r,

now this idea i like :cool:
as would all be ready for when i put the bike carbs/megajolt on, hmmm now i best get looking at those links in detail.:eek: :)

thanks for this info.

cheers
andy