Help 460 vacuum lines

[Dgordon013]

Hi,

Thanks to Gary I have progressed but still have a few hoses I do t know where they go

It’s a 460 from 1977/8 with motorcraft 4350 imported from the US in a Camper

We are in England though

I took some pictures which I will try and attach here

Essentially, one red tube coming from the vacuum tree

One black tune coming from the middle of the rear of engine manifold cover (behind carb in between the V)


One metal tube coming from rear of car ( fuel tank) which I am sure is to vent some excess gas but which tube goes into there


Air filter hasbtwo tibe connections and not sure where those go either

Maybe one of you specialists can help me
Thanks and best

Daniel

[Dgordon013]

[Gary Lewis]

Daniel - Welcome!  Glad you joined.  

Here we specialize in 1980 - 86 trucks.  So our vacuum-routing diagrams won't be exactly the same as what you are seeing.  However, the basics are the same, and I think these are they:

Vacuum Advance: I can see multiple hoses in your pics associated with the vacuum advance unit on the distributor.  If they are all connected properly it'll work fine, but it can also be simplified.

Transmission: If you have an automatic transmission it will surely be the C6.  And there will be a tube or hose going down to the right side of it.  I suspect that's the red tube in the second picture, and it needs to go to manifold vacuum.  And manifold vacuum is what the hose in the first picture is.  So, those two could go together, although they appear to be of differing sizes.  Check out where the red tube goes first.

Vapor Recovery: As said in the email, there's a system to recover the vapor from the evaporating petrol.  The tube running from the gas tank should go to one or two charcoal canisters sitting low on the right frame rail, probably below the battery.  And there will be a few vacuum hoses associated with that, including one from the canister(s) through a valve to the intake manifold or carburetor.

Does this help?

[Dgordon013]

Thank you Gary.. pleased I joined and found this.

Very helpful

So the orange metal tube indeed goes to the transmission so I connected it to the red black tube from the man vac now

I looked for the cans but can’t find any .. bit the egr.. maybe someone prior to me took it off ?

It now starts  and runs fine but after a few minutes dies unless I slightly open the choke plate by hand .. so need to check out why that does not happen automatically


Also, does anyone know which two tubes connect to the air cleaner, which seems to have a bimetal switch with two tube connections ?

Then,

One day Would love to simplify the setup as all seems unnecessarily complicated with all that emissions stuff

[85lebaront2]

The blue "can" on the back of the passenger side of the carburetter should have manifold vacuum applied to it. It is the choke pull-off and opens the choke (strangler) blade after a few seconds of running. It has a bleeder system (cover on back) so is harder to test than a plain one. The choke control is a bimetallic spring in the choke cover which gets it's heat from the exhaust crossover passage in the intake manifold. The tube in the back of the choke housing should get quite hot fairly soon after starting the engine, if it does not look for a broken tube (rusted through) or the inlet tube (goes next to it) being blocked or used as a vacuum source by mistake. It normally is connected to a nipple on the upper part of the carburetter.

[Gary Lewis]

Daniel - Bill not only knows how to spell carburetter, he is also very knowledgeable with them.  In addition, he has a truck w/a 460, and it was originally plumbed as shown below.

I've circled the two air cleaner diverter valves in red.  You can follow the hoses back down to a tee, and from there to a fitting on the manifold called "MAN VAC".

[85lebaront2]

Unfortunately being a 1978 it has the infamous Motorcraft 4300D on it.

[Gary Lewis]

Yep, that's the 2150 with secondaries - right?

[Dgordon013]

Thank you all
Yes it’s a 4350 on it

Do you know the meaning of the different colours in the various tubes?

Red, blue, yellow etc... ?

Which colour should go into the blue thing that moves the choke?

And the diagram shows the red ones going to the air cleaner?

[Gary Lewis]

I don't know if there is a meaning for the colours on the diagram.  But, it is possible that the original hoses had a colour tracer on them, so you might look for that.

HOWEVER, the diagram above is not for your truck.  It is for Bill/85LebaronT2's truck, which is an '86.  So it doesn't really apply.  I was just using it for an example.

So, to answer your question, Bill said the blue thing, the choke pulloff, goes to manifold vacuum.  So you can hook it up to a hose, or run a new hose, to a fitting that screws directly into the intake manifold.  For instance, there may be a fitting in front of the carb that is screwed into the manifold and has several taps on it.  You can use any of those.

And if this doesn't make sense post up a bunch of pictures showing the engine and where each hose goes.  Maybe we can find the right one.

[Dgordon013]

Great
Thx will try that out and run a line from the man vac tap to that

It’s just my van has the same coloured hoses so there might be some logic to it


Let’s see .... thanks again from cold England

[Dgordon013]

Hi all

So I figured most of it out in terms of what Jose goes where

No it starts and runs ok as long as I manually keep both choke plates open when starting

I think it is time for a new carb

What type of edelbrock would I need for the engine ?


Also, if I want to take most vacuum hoses off, can you remind me which ones I must keep ?


Thanks so much

Daniel

[Gary Lewis]

This page explains what vacuum hoses an '80 - 86 truck needs: http://www.garysgaragemahal.com/vacuum-systems.html.  But yours isn't a Bullnose, so may not need the vacuum hose to the heating and A/C systems.

But, that page doesn't include the vacuum choke pull-off that your choke needs.  So if you keep that carb you'll need vacuum to that.

So, let's talk carbs.  In my opinion, which many on here don't share, the most simple and reliable carb is an Edelbrock, which is what you asked about.  So here goes.

To fully feed a 460 at full-chat you'll need a 750 CFM carb.  But from what I've read the 4350 is a 600 CFM carb, so if you are just wanting to match that an Edelbrock 600 CFM carb would work.  But, they also have a 650 and a 750 CFM carb.  However, those carbs are across three different carb lines:

Performer: This is essentially the original Carter AFB, which was a very good carb.  I'm running the 750 CFM version on my 460.

Thunder: This is based on the younger brother to the AFB, the Air Valve Secondary (AVS).  The major difference between the AFB and the AVS is the adjustable secondary opening point.  Adjusting the AFM is very difficult as it requires disassembling the carb and adding to or taking weight away from the secondary air valve's lever arm.  But the Thunder/AVS has an extremely easy-to-use adjustment on the secondary opening point.

AVS2: This is a new carb and I'm not au fait with it.  But, from reading about it I think it is the Thunder/AVS with annular discharge venturiis.  This should be helpful on economy, but then I'm not sure "economy" and "460" should populate the same sentence.

Having said all that, from what I read your 4350 is a "spreadbore" carb , and that is going to be a minor problem.  You might want to read this: http://www.drbob.tqhosting.com/tech/carb/4350_compared.html as you are going to need an adapter to bolt another carb on that manifold.