A Closer Look at the Carb Setup with Questions

[1969VAGTX]

So I finally got under the hood of this Hemi this morning to take a look at what's going on. From my previous thread, I mentioned that I didn't think this thing has a choke setup - that is confirmed. Presumably I can order all of the necessary components to add a choke to this dual quad? I have found the choke kit and heat tube parts at YearOne and other retailers. The only thing I can't seem to find is the linkage rod for the top of the choke.

Also, while inspecting this I noticed the little green "thing" with two tubes coming out. One of the tubes connects to the rear carb. The other tube was just sitting plugged up across the front of the motor. Where should that be plugged up? I don't see a vacuum fitting on the front carb that is where I would assume it should go.

(same line from the previous picture)

Last thing, any thoughts on the carb linkage? My gut reaction after reading through the service manual a couple times is it is not adjusted correctly. Would appreciate any thoughts and feedback. Thanks.

 

[Runcharger]

OSAC valve I think that is called, You're lucky it's there. I set the connector linkage so the front carb reaches full (wide open) throttle the same time as the rear carb.

 

[pnora]

Get a hold of Scott Smith on your carb parts. http://www.harmsauto.com/home.html

 

[pnora]

The valve is the Distributor vacuum control valve. And the vacuum lines are on it wrong.

 

[1969VAGTX]

The valve is the Distributor vacuum control valve. And the vacuum lines are on it wrong.

Any pictures of how it should be connected?

 

[pnora]

ISTRIBUTOR VACUUM CONTROL VALVE
ADJUSTMENT (Fig. 2)
(I 70 Cu. In. Engine, Manual Transmission
and 426 Hemi Engine, Manual and Automatfc
Transmission only)
(1) Connect a tachometer to engine and warm engine
up to normal operating temperature.
(2) Connect a vacuum gage (0-30 in. mercury) to
distributor vacuum tube. The tee should have same
inside diameter as distributor vacuum tube.
(3) If carburetor is equipped with a dash pot, adjust
it so that it does not contact throttle lever at
curb idle.
(4) Clamp closed vacuum tube that connects vacuum
valve to manifold vacuum.
(5) Remove distributor vacuum tube at distributor
and clamp tube closed.
(6) Set basic ignition timing to manufacturers
specifications*. The curb idle speed must be at specified
rpm before timing is adjusted.
(7) Adjust carburetor to obtain specified engine
speed and exhaust emission level. The distributor
vacuum must be below 6 in. of mercury at curb idle.
(8) Remove clamps from vacuum tubes and reconnect
vacuum tube to distributor. Remove vacuum
valve cover (Fig. 2).
(9) Speed engine up to 2000 rpm in neutral and
hold speed for approximately 5 seconds. Release
throttle and observe distributor vacuum. When throttle
is released, distributor vacuum should increase
to above 16 inches of mercury and remain there for
a minimum of 1 second. The distributor vacuum must
fall below 6 inches of mercury within 3 seconds after
throttle is released.
(10) Adjust valve if necessary. Turning spring end
adjusting screw counterclockwise will increase time
the distributor vacuum remains above 6 inches of
mercury after throttle is released. One turn of adjusting
screw will change valve setting by approximately
1/2 inch of mercury. If valve cannot be adjusted
to specifications described in Step No. 9, re- place valve (Fig. 2).
(11) Replace vacuum valve cover. Reset carburetor
dash pot (if so equipped) and check valve
performance as outlined in Step No. 9. If distributor
vacuum does not fall below 6 inches of mercury
within 4 seconds after throttle is released, readjust
or replace dash pot.
MANIFOLD\
I VACUUM h
ACUUM ‘ UNIT I XKtW
I ’ COVER I l’’ NN705
Fig. 2-bistribv)or Vacuum Control Valve

Any pictures of how it should be connected?

 

[pnora]

I tried to copy a page from the FSM. Get the manual and in group 14 it is explained with a photo.

 

[1969VAGTX]

I tried to copy a page from the FSM. Get the manual and in group 14 it is explained with a photo.

Found the description in the service manual. Now where exactly are each of the connection points (manifold, carb, distributor) located?

 

[1969VAGTX]

Upon further inspection, the whole setup appears screwy. There is no vacuum tube connected to the distributor at all. I assume the carb connection is where the wrong line is currently routed. That just leaves me with the question of where to connect the tube to the manifold. I don't see any obvious fittings on the back of the engine or manifold.

 

[pnora]

Found the description in the service manual. Now where exactly are each of the connection points (manifold, carb, distributor) located?

Just like it says. The manifold would be direct Vacuum, 2 the carburetor which would be ported vacuum, 3 distributor. From what I see you need a manifold source. What goes to your vacuum advance now?

 

[pnora]

Upon further inspection, the whole setup appears screwy. There is no vacuum tube connected to the distributor at all. I assume the carb connection is where the wrong line is currently routed. That just leaves me with the question of where to connect the tube to the manifold. I don't see any obvious fittings on the back of the engine or manifold.

I assume there must of been a fitting at the rear of the manifold. Should be a plug. Otherwise the carb would have to have a non ported fitting capped off.

 

[1969VAGTX]

Just like it says. The manifold would be direct Vacuum, 2 the carburetor which would be ported vacuum, 3 distributor. From what I see you need a manifold source. What goes to your vacuum advance now?

Apparently nothing.

 

[1969VAGTX]

I assume there must of been a fitting at the rear of the manifold. Should be a plug. Otherwise the carb would have to have a non ported fitting capped off.

I assume there would be a fitting here (white arrow), but it appears a screw in plug was installed.

 

[pnora]

For what its worth most guys bypassed that valve. It takes some screwing around to get them set right. And even then you most likely would get a better tune without it. Restoration correct you want it. I am sure Scott Smith had photos and parts to set this up period correct. It is not going to be cheap and its possible your carbs could have internal mods that might make this difficult.

 

[pnora]

I assume there would be a fitting here (white arrow), but it appears a screw in plug was installed.
View attachment 1253892

Most likely that is the port. My guess.

 

[AR67GTX]

your main throttle link is on backwards. The slotted end goes on the front carb. Not sure how it even works like that.

 

[1969VAGTX]

For what its worth most guys bypassed that valve. It takes some screwing around to get them set right. And even then you most likely would get a better tune without it. Restoration correct you want it. I am sure Scott Smith had photos and parts to set this up period correct. It is not going to be cheap and its possible your carbs could have internal mods that might make this difficult.

If it's not needed then I won't worry about it. Ultimately, I am just focused on getting a choke set up on this thing and getting all of the linkage set. I have a shop that is going to help me with that. Might even have them stick an electric choke on it. Doesn't have to be absolute correct. I want functional for driving. Just trying to educate myself on this unfamiliar to me monster.

 

[pnora]

.View attachment 1253812

your main throttle link is on backwards. The slotted end goes on the front carb. Not sure how it even works like that.[/QUOTE]
It will work either way.

 

[pnora]

If it's not needed then I won't worry about it. Ultimately, I am just focused on getting a choke set up on this thing and getting all of the linkage set. I have a shop that is going to help me with that. Might even have them stick an electric choke on it. Doesn't have to be absolute correct. I want functional for driving. Just trying to educate myself on this unfamiliar to me monster.

Electric would be a good option. Just need the housing and link along with the choke spring. One power wire and it should work.

 

[1969VAGTX]

your main throttle link is on backwards. The slotted end goes on the front carb. Not sure how it even works like that.

It will work either way.[/QUOTE]
The linkage all seems to work. What exactly is presumably on backwards? This looks like the setup from the service manual, unless I missed something.