460 Air Cleaner Vacuum Lines

[kramttocs]

These two, hereby called yellow and green:


Right now they are unplugged but want to hook them up as I think they should be (?).

From a hazy memory they were hooked up to a manifold vacuum tree near the front but that was also when it was fully smogged so vacuum lines galore.

I don't have a tree in the front right now and am trying to have as few capped off ports as possible.

Thus, can I use either or both of these carb ports for these?




Side being ported and bottom full since the ported on the bottom is hooked to the vac adv. Speaking of - that's correct for the vac adv to be hooked to ported, right? Don't think I asked Scott about that.

[FuzzFace2]

kramttocs wrote

Thus, can I use either or both of these carb ports for these?
This port should go to the dist. vacuum advance can if you have one. If not what are you running for a dist.?

You could use this port if it has manifold vacuum or any port on themanifold that has vacuum all the time.


Side being ported and bottom full since the ported on the bottom is hooked to the vac adv. Speaking of - that's correct for the vac adv to be hooked to ported, right? Don't think I asked Scott about that.

See my replies by the pictures.

Oh I should also asy if you don't have the snorkel hooked up to hot air off the exh. manifold and / or cool fresh air thru the radiator support I don't see the need to hook up this temp switch.
Dave ----

[85lebaront2]

Damn, it's been a long time since I sent Jim (ardwrkntrk) my old air filter. The green delay valve needs manifold vacuum as it's function is to hold the auxiliary air door closed until the vacuum drops. The other line on Darth's went to the top of the air filter to a thermal control valve then to the inlet snorkel vacuum motor. It's function was to heat the incoming air until everything warmed up to allow a leaner mixture for emissions to be used. That one I believe went to the vacuum tree in front o the carb.

[kramttocs]

Dave/Bill - appreciate the info.

I should better explain the carb since as Bill said in another thread - it's a universal one so a few changes from factory.
It has 3 vacuum ports not counting the large one in the back.

1 full manifold - located at the front base (see capped port in the second carb photo above)
2 timed-spark/ported - located on the side (capped currently) as well as at the front base.

The timed port at the base is currently hooked to the vac advance. First off I need to confirm that this is correct. My understanding is that with the emissions hook up it is but not sure about a non-emissions motor. Scott has all my specs when he recurved a distributor so might be worth me giving him a call on Monday.

I do have the fresh air snorkel going to the core support and the heat tube hooked up to the one of the tubes on the header. So same-ish as stock in that regard.

So green will get the full manifold. Check.

Yellow. Even though I have the heat tube hooked up, since I don't have the emissions getup will I benefit from hooking that one up to full manifold?

[ArdWrknTrk]

Both go to manifold vacuum.

Green allows the air door to open under WOT acceleration (low vacuum)

Yellow is the thermal valve that controls the flap in the snorkel, and tries to keep inlet air at ~105*F IIRC.

[Rembrant]

Scott,

I don't have a 460, but I have a complete de-smogged 302 with a Holley 4160 (with all the same vacuum ports as yours).

The upper barb (above the mixture screw next to the sight glass) is the timed spark vacuum source for the distributor.

The barb at the base is full vacuum. I have this one routed to the air cleaner. It is routed to the thermo valve first, and then to the green (CWM?), and then to the dual snorkel air motor/valves.

I removed everything else.  

[Gary Lewis]

kramttocs wrote

Even though I have the heat tube hooked up, since I don't have the emissions getup will I benefit from hooking that one up to full manifold?

Yes, you will.  It will help with the choke in winter, and it will help prevent carb icing in damp, cold weather.

On the choke, electric units aren't the most accurate to track engine and weather conditions.  In my experience they can be finicky - a little more choke to help cold weather can mean too much for warmer weather.  But the heated air helps lessen the problem by allowing the choke to come off a little earlier.

[FuzzFace2]

Rembrant wrote

Scott,

I don't have a 460, but I have a complete de-smogged 302 with a Holley 4160 (with all the same vacuum ports as yours).

The upper barb (above the mixture screw next to the sight glass) is the timed spark vacuum source for the distributor.

The barb at the base is full vacuum. I have this one routed to the air cleaner. It is routed to the thermo valve first, and then to the green (CWM?), and then to the dual snorkel air motor/valves.

I removed everything else.

Scott, recheck that base vacuum you say is timed / ported vacuum as I have never seen any base ports be timed / ported on the one up by the float sight hole.

The way Cory has his is how I have mine even if it is a 300 six as that system works the same way on any size motor.

FYI I don't have the heat hose to the EXH. manifold because I am running EFI manifolds and no way to really get heat from them. In my case it does not get that cold here and if it is pulling a little warm air then good other wise I don't worry about it.
Dave ----

[kramttocs]

Thanks guys. I'll pickup a Tee and use the full vacuum port at the base of the carb to feed both.

Dave - this is from the manual. Not sure if there is a good reason to use one over the other - I just chose the bottom one to keep the line out of the way.

[FuzzFace2]

Must be a new Holley thing as I have never seen that on a Holley carb before only the one on the side.
Dave ----

[ArdWrknTrk]

Holley's have changed some Dave, since they installed the blowout check valve's and non adjustable floats.

 

[Rembrant]

kramttocs wrote

Thanks guys. I'll pickup a Tee and use the full vacuum port at the base of the carb to feed both.

Dave - this is from the manual. Not sure if there is a good reason to use one over the other - I just chose the bottom one to keep the line out of the way.

Well that's interesting. My 4160 is relatively new...purchased only about 2 years ago, and it has the two angled barbs like the upper right hand picture above. I can tell you that the bottom barb on mine is full manifold vacuum as that is the port I used for my vacuum gauge when I was getting everything set up. I wouldn't be able to use it for the distributor in my situation as I would have full vacuum advance at idle.

[grumpin]

My 4160 is fairly new also, 2 years old max, I think. 3 ports, two full vacuum and one timed spark vacuum source.

[kramttocs]

Hmm, this is a quick fuel variant so it has some extra adjustability but wouldn't have expected the vacuum ports to be different.

So forgetting the pcv big port on the back, either of you mind posting some photos of yours?

[ArdWrknTrk]

I can take pictures of my 600 and 750 in the morning, if you like.

Both are basic 4160 style carbs.
The 750 has a quick change secondary, and K&N stub stack.
Additionally it is fitted with a Motorcraft choke element.

[Rembrant]

kramttocs wrote

 So forgetting the pcv big port on the back, either of you mind posting some photos of yours?

I have the large port in the back supplying the vacuum to my brake booster. The side timed port supplies the distributor vacuum advance, and then I have the two 45* angle ports at the base in the front...one small, one large. The large one I have connected to my PCV valve, and the small one goes to my air cleaner. That's it for vacuum lines on my 302. I can take some pics no problem, but see below some pics from one of my Holley carb books. I have 3 of these for coffee table reading, but mine is connected as per these pictures. Mine is just a basic 4160 with vacuum secondaries and electric choke.

[kramttocs]

Thanks!
The two 45 degree ones at the base of mine are very similar in size and match the Cast Billet Model photo (middle left). I don't really know much about the QF ones but still a little surprised those two ports behave differently despite still being 4160's.

Jim - if you get a chance, I'd be interested in looking at some photos of yours also.

[Rembrant]

kramttocs wrote

I don't really know much about the QF ones but still a little surprised those two ports behave differently despite still being 4160's.

I don't know much about the QF carbs either, but the shop that built my 302 said they use them all the time and were very happy with them. The reason the topic came up was I asked them what carb they would have installed on my engine, and they said QF (instead of the basic 4160 that I supplied to them).

Edit: Now that I look at all the pictures, it looks like QF carbs must use different bases. See in the picture I posted about from the Holley book that there is one slot machined in the base for the two barbs? They are both on the same manifold vacuum. But when I go back up and look at your pictures, it shows separate slots machined for the two ports. Very interesting. Hope I didn't cause any confusion here Scott. I would have assumed that Holley would use the same bases, but I guess not.

[ArdWrknTrk]

I only know QFT  Dominators.
QFT were a breakaway company, started by a former employee.
But they had QC issues, with carbs sent out with debris and such.

At least they were still American made.

Another cup, and ill go get those pics...

[ArdWrknTrk]

As promised, from the grange....