Carb Plumbing help

[GoinBroke]

I will need to hook up a fuel line from a mechanical pump to a BG speed demon carb on a 351W based engine in the near future. Please let me know what has worked for you and any suggestions for mine would be greatly appreciated. I am looking more for the braided steel or steel line setups with an intregal pressure gauge. I am not to up on the -an sizes and stuff so details are very helpful.

 

[truck90278]

If you are going to go the stainless braided route, then contact Pure Choice, Russells, or Earls. I would suggest Pure Choice. They are smaller and will spend more effort helping you than probably the others. Depending on the use, a "-6 AN" hose is probably adequate. this is approximately 3/8 of an inch ID.

 

[66Graven]

-AN plumbing is simply a short form designation for Army/Navy. The number beside it is actually short for the number of 16ths of an inch. A #6-AN fuel line would denote a 6/16 (hence 3/8) size line, from the Army Navy plumbing spec. You would want an albow adapter from the fuel pump, connected to about a 14" braided line into a fuel filter then 8-12" line into the fuel line splitter for the bowls on the carb.

Hope this helps.

 

[GoinBroke]

Thanks for the help guys!

 

[SoCalCruising]

I think that your mech pump threads will be pipe threads. If so, you will need a pipe-to-AN adapter at the pump for your AN connection. At least, that's how mine is set up. The inline fuel filter is something that should not be left out. A large, low restriction filter is often also used on the line feeding the mech pump. Fram sells a nice one that you can mount on the fender apron near your fuel pump. Your tank would feed to that filter, then from there plumb to your fuel pump. A smaller filter can then be used b/w the pump and carb.

 

[GoinBroke]

The outlet on the pump is 1/4" NPT so I am debating whether to hose barb it and plumb with a braided 3/8" SS hose or go with the -6 from pump to filter to dual feed setup for carb. I put together the feed line from tank to fender apron today and integrated a filter where the stock pump mounted to the rear undercarriage. I certainly want it to look good but I surely do not need any fuel starvation issues with a new engine.

 

[SoCalCruising]

You can certainly use a barb on the input line from the tank. AN fittings ARE a bit of a hasle to mount up on the braided line, but, once you get the hang of it, it isn't terriible. If you take the time to make a nice SS braided line with AN fittings, you won't regret it.

 

[67Dylan]

One question; how are you going to control pressure?

Here's what I recmnd: from the tank to the filter, to the pump, then to the front of the mustang. From there, go to a pressure regulator, dual lines to the carb and one line back to the tank; all from the FPR. Keep the bends of the fittings less than 90* as much as possible, but if you can't then don't sweat it. There is no need, IMO, for dual filters.

Size of lines can be determined, but I'm not up to speed on your combo or expected HP.

 

[GoinBroke]

The mechanical pump states it does not need a regulator. I am concerned about the line size supplying the set up I am putting together. Should the 3/8" ID supply the setup below ok? This is not to be a race car just a strong street engine.

408CI, 10.2CR, Alum. heads, Weiand stealth dual plane intake, 750 doublepumper, .541 lift cam and stepped 1 5/8 to 1 3/4 headers.

 

[dennis112]

The mechanical pump states it does not need a regulator. I am concerned about the line size supplying the set up I am putting together. Should the 3/8" ID supply the setup below ok? This is not to be a race car just a strong street engine.

408CI, 10.2CR, Alum. heads, Weiand stealth dual plane intake, 750 doublepumper, .541 lift cam and stepped 1 5/8 to 1 3/4 headers.

I have a somewhat similiar 393w motor-specs in sig. I use an aftermarket "Street" mechanical pump (7lbs), no regulator, 750dp, a single 3/8" line (from tank to pump and from pump too fuel long) AND a 3/8" pickup tube in the tank. All lines are steel, except for a little bit of 3/8" rubber tubing where the necessary connections are made at the fuel tank, inlet to the fuel pump, and at the fuel log. I hand bent the line from the fuel pump that goes to the fuel log.

I shift at 6400 and have no fuel issues as it is still pulling strong at the upper end in each gear.

 

[67Dylan]

I'd say the 3/8" tube will be perfect for your combo.

 

[GoinBroke]

Thanks for the info guys. I am 3/8's from the pickup to the drivers fenderwell now so I will keep that ID to the carb. I need my tranny to be delievered before I can drop the engine and finish the plumbing. It will sure be fun to start putting parts back on the car instead of taking stuff off of it!