People Running Carbs: How Have You Run The Fuel Lines?

[Stu 18]

Hi all,

 

Im thinking of ways to run the fuel lines and such for when i swap over to carbs.

 

Ill be using a red-top pump, ive not decided where yet, im thinking quite close to the tank, and probably inside the car.

 

So, do i run the lines inside the car, or outside? Im thinking inside, and do it all in 8mm copper and clip it to the shell. Come off the existing fuel pump outlet from the tank (injection pump removed obviously and replaced with a length of pipe) in flexible fuel hose to the copper.

 

Then, gromet the bulkhead and go into the engine bay with the copper, with the reg mounted by where the battery used to be. Im going this way as the fuel unions on the Dellorto's favour fuel being fed from the right. This is also why i didnt really want to use the existing injection fuel lines.

 

Then just use fuel hose from the reg to the carbs.

 

How does this sound? Is the 8mm big enough to deliver enough fuel? What do you guys do with the second union on the old pump used for the return?

[Baz 421]

Mine's just one braided line from the dummy pick up in pump, under the car and into the engine bay, into the facet pump, then to the regulator, then filter then carbs.

 

I should think inside with copper will do the trick as it's a track car.

[Stu 18]

Yeah thanks Baz, i guess it doesnt really matter how its done provided its leak free

 

The only reason i kind of wanted to run it inside is like you say, a good 'off' into the gravel might ding it if its on the outside, and it does make it easier to pipe up if i run the pump inside the car.

 

I remember reading something Mei had said about bulkhead fittings and such, now i like the idea, but they seem to be bloody expensive, and i cant quite get my head round the -6 thing etc, anyone know what 8mm equates to in these fittings?

[Stu 18]

Also, is the 8mm copper up to the job of delivering enough fuel? I *think* its approx .75mm wall, so is almost the same as the stock lines overall internally?

[brumster 135 1 Cars]

JIC - from my notes :-

 

Tube outer diameter is measured in a dash size, or 'AN'. All fittings used a UNF thread, 37 degree flared seat, sizes start at -2 up to -32 with each increment being 1/16th of an inch. Thus -6 is 3/8th inch O/D.

 

Each size has it's own thread spec. -6 uses 9/16-18 SAE thread size.

[BackStreetRacecars 3]

Mine's just one braided line from the dummy pick up in pump, under the car and into the engine bay, into the facet pump, then to the regulator, then filter then carbs.

 

I should think inside with copper will do the trick as it's a track car.

 

 

sorry to jump in here but.... when you say dummy pick up in pump.... do you mean one from a carb model 205? or have you fabricated something to suit??

[hexhamstu 9]

sorry to jump in here but.... when you say dummy pick up in pump.... do you mean one from a carb model 205? or have you fabricated something to suit??

piece of copper pipe with a bend in it. theres a guide on the main page which has a few pointers in it.

[pip470 61]

Heres a few pics showing how ive done mine.

 

Please note, the picture of the copper pick up pipe, CAN NOT protude the bottom of the pump casing as the pic shows. This version did not work as it does not fit in the tank so I had to chop the pipe down a bit.

 

The regulater is mounted on the headlight bit of the slam panel in between the pump and the carbs. Hope these help.

Edited March 26, 2009 by pip470

[Mark205 1]

Pip, do you have much trouble with bonnet clearence with that airbox.

 

I have a set of bike carbs on mine and i have trouble with clearence.

 

Any ideas on how to get around it without the use of bonnet pins.

[pip470 61]

Ha ha major isues with clearance, I decided not to fight it and go with it so, one big hole in my fiberglas bonnet, and four bonnet pins and hey presto. Ive now made a fiberglas bulge to cover the hole but its still a work in progress so cant be shown yet but I can show how bad it was.

[Mark205 1]

I can't/will not do that to mine as its a road car and i want it to look like one.

 

I suppose i will have to chop/remake my manifold.

[pip470 61]

I didnt want to but its only until i buy some propper throttle boddies and then ill fit the standard bonet back on. I have no choice with the trip coming up in 5 weeks so making a new manifold this late in the game would be risky.

[Stu 18]

Thats a big, big help mate, many thanks. Ive been struggling to find a way of doing it to be honest!

 

So thats '6 engined yeah? Did it fuel ok with the pump being there? I was going to try and keep it by the tank to be honest, but the more i talk to people the more it seems this isnt necessary.

 

I like the pump being there, nice and out of the way

[pip470 61]

Yup its a 6 engine and so far Ive had no incling of any fuel starvation. Seems to pull the fuel through no problem. The rolling road guy never mentioned it so disregarding the original instructions seems to be ok in this case. The fuel pressure regulator is set to just above 3 psi. I'm glad it helped.

Edited March 27, 2009 by pip470