Hi

My tri-power 2ndarie carbs have 2 ea vacuum ports side by side.
I saw others with only 1 ea port.

Which port do I have to connect the 2ndarie vacuum pods to ?

On the pic very left side you can see both ports, I mean.



Günther

 

Hi

Nobody knows ??

Günther

 

Can you get a better pic?

I can't quite see the thing.

 

Hi

This one better ?



Do I need to connect the rubber hose that comes from the primary carb vacuum port to the copper tube or the the silver one on the 2ndary carb to operate the vacuum pods ?
Do I have to cap the other , unused one ?

Günther

 

Gunther,
The carbs look like they have been modified. All the tripower secondaries I have seen only have one nipple where you have two.
Where does the unconnected nipple flow to? if it is parallel with the first nipple, block it off.

 

Is it possible that you have a center carb main body instead of an end carb main body? What is the LIST number on the end carb in question?

 

I just looked at my setups... all 3 carbs have the identical nipple for the vac connection, which is on the carb body.

The vac cans do not have any nipples.

It looks like the copper nipple is in the vac can?
If so, either you have the wrong vac cans, or somebody modified yours.

The vac cans for TriPower are not the "standard" size... they are larger and do not fit other carbs.

Sooo.... looks like somebody was messing with them.

In the pic, the vac line goes on the nipple nearest/on the main body.

 

Hi

List number of the 2ndaries = 3659. primary = 4055-1, semms to be OK for 69 as per the black book, or ?

The cans have a diameter, measured between the srews of about 3 1/2 ", 9 cm . Looks like if bigger once could not be installed.

The outer copper tubes go to the cans and open those. The inner silver tube is the same as the primary has and ends up inside the carb.

The carb bodies look very similar, but have some differences, like the outbds have extra bosses to mount the vacuum pods , no holes drilled for the choke etc.

So, whats wrong with this setup ? Nothing is simple on the end with this old vehicles.

And there is a ink stamped numbering on the vacuum pods caps , not very readable , but could be 8156.
Can't see any other numbering on the cans. Should there be and where ?

Günther

 

The second (copper) tubes are not correct or OEM.

Are they in the cans, or in the carb body?

You'll probably have to plug them as already suggested.

My guess is that somebody wanted a different vac source to operate the secondaries, so they installed their own tube.

The original vac source is transferred via the original tube through a cork gasketed port to the can.

 

Hii

Just saw this on E-bay.
http://cgi.ebay.com/ebaymotors/Holle...74773460QQrdZ1




The vacuum cans tube here looks similar as the copper tube in my setup. It is also in the same location, actually in the vacuum cans socket.
The E-bay carb body does not have a port, but myne has, exactly in the same location as the primary body has.

I guess that my cans are OK, but the secondary carb bodys have this extra port that is not used on this setup , hence should be capped.

Can anybody take a close up pic of his setup, mainly the 2ndary vacuum ports tubes area ?

The carb body's port is open to the carb side, not gasketed.
I will install a overhaul kit anyway, hence take them apart and look if this is possible to close the port to the carb and open it to the cans. My guess is , that it is not possible on my carbs because the cans copper tube does not look fiddeled, but very professionally done.

Günther

 

The gasket I was referring to is between the can and the carb body.... not on the tube.

My setups (400HP) have single tubes, all in the carb body, none in the cans.

I can take pics of it all & send 'em.

Possible you may have cans off a MOPAR... I'd have to research that. Been a while.

I have been rebuilding these for 30 years and never ran across double ported setups.

 

Hi

Thanks for the time and replys.

It looks like if it doesn't realy make a difference on the operation.
The ctr carb vacuum is operating both outbd carb vacuum pods and this is happening on my setup through the copper outer tube. The inner tube is open to the carb side ( air inlet ) same as on the ctr carb.

Even if I would open up a possibly existing passage between the carb and can for the inner tube, it would still stay open to the air inlet, hence loose the ctr carb vacuum to there. Or do I misunderstand the operation of the cans ?

Could you also get me the dimensions of the cans, may be as I mentioned B4, measured between the cover screws, center screw to ctr screw. My cans have a touch over 3 1/2 " , exactly 9 cm.

This would at least tell me, if the cans are correct.

I am using 3 rebuild kits from ACDelco, 1 # 9689 and 1 # 07039689.
Is this the correct kit for primary & secondary carbs ?

Again, thanks for all help. This is the first tri-power setup I get my hands on and surely want to get it working right on my 68.

Günther

 

Go here...

http://www.holley.com/data/TechServi...ded%20View.pdf

It shows the vac can with no tube.
It shows the small cork gasket between the can and the body,
and it shows the body with the tube.

I'll take some pics but I can't post them... I'll have to email them to you.

Edit...
Here is a MOPAR can... I can't see a tube in it either.

http://www.sixpackperformance.net/im...vacpot-big.jpg

 

Hi

Thanks.
May be the copper tube has been retrofitted by somebody not knowing how to block the air passage of the carb body tube to the carb air inlet and opening it to the vacuum pod.
I will find out once I take the carb apart for overhaul.
Again, I don't think it makes a hell of a difference if at all to the ops the system. I will have to block either one of the tubes.

What throws me off a bit is the E-bay add pic that clearly shows the tube coming from the pod's flange and no tube on the carb's flange. I just have both somehow.




Will post the outcome once I'm at it.

Günther

 

I'm going to check the air passages tonight... but if I remember correctly, the end carb passages in the main body are not the same as in the center carb. I seem to recall that the end carb passages are for assisting the carbs shut on deceleration edit: or for assisting in getting them fully open once they start to open. I ferget. Ford TriPower.... MOPAR TriPower.... Chevy TriPower... Pontiac TriPower... it all blends together these days.

I don't think your setup will work properly unles you sort it all out.

The ebay pic sure looks like the can has a tube, but it could be an illusion due the camera angle.

 

Here's my take on it. Mine has just the inner ports, and when I first started to fuss with 'em I hooked up the hand held vacuum pump and went to it, thinking I'd test the diaphram. It didn't hold vacuum at all, so I tore it down to check it all out. Everything looked good and I couldn't figure out why the port split with one side going to the diaphram and the other venting into carb just above the venturi area.

Luckily, I found out that this was the proper setup before I started messing with it! Heres how it works: when you call for the secondary carbs to open (full throttle), the center carb delivers maximum ported vacuum to the diaphram ports and at the same time the vacuum slowly starts to rise INSIDE the venturi's of the secondaries as they slowly start to open. Thus, the diaphram no longer "bleeds" from the venturi, but actually gets vacuum from two sources. It has to be this way so that they close quickly and totally when you back off the throttle, hence the "bleed" port!

The effect is that the secondaries come on gradually instead of all at once for a very progressive effect, instead of violently (often with a stumble) like on a GTO with triple Rochesters. Those really come on with a vengence even though they're progressive.

I'd guess someone added the second port in that spot (I definitely feel it's a mod) to make them actuate almost instantaneously, probably for drag racing. You could cap them, or pick up some aluminum rod and make a plug for each one.

I find that this setup is the smoothest, cleanest one I've ever driven, and I've had or still own a bunch of multi-carbed engines.

P.S. the secondary operation CANNOT be tested by snapping the throttle in the driveway! The engine has to be under load, so a dyno is required to visually check this, unless you have a fender monkey ;-)

Hans

 

Okay..... I disassembled 3 carbs... two 4055-1's and one 3659.

They all have the exact same holes drilled in the carb body. (almost.... I'll get to that later)

One hole is drilled through the body into the venturi just below the ridge, across from the high speed venturi.

If you hold the carb with the D pointing up, this hole is at about 2:00. On the outside, this hole mates via a cork gasket to the vac can (3659 only).

The second hole is for the tube for the hose connection.
It connects internally to the first drilled hole.

But... the center carb (4055/4056) has the first hole blocked with a plug so that the connection cannot be made to the vac can.... while the second hole still connects to the venturi.

I used air pressure to trace the passages.

And guess what?

This end carb was correct:
3902353-EU LISDT 3659 Date Code 781
This center carb was correct:
#3940929-EV LIST 4055-1 Date Code 951
This center carb was not correct:
#3940929-EV Date Code 212.

On the second 4055-1, I could not locate the hole in the venturi. So I huffed, and I puffed, and.... used a magnifying glass and a flashlight... and guess what? The hole was NEVER drilled into the venturi.

Now I know why the guy sold me the entire setup (including the coveted idle solenoid & bracket) for just $100. He could not get it to work no matter what.
And neither would I if I had not done this test for Gunther.

I owe you a beer Gunther!

PS- I have some pics to send.

 

Hi

Thanks for all explanations on the function of the carbs. I now know better.
I will have to take this apart to correct the can's function.
This setup was also sold to me rather cheap ( for today's asking prices ) because the original owner could not get it to work properly.

Tom454 , I did sent you a E-mail for my address and am desperately waiting for pics.

It looks like my 2ndary carbs venturi ystsem is blocked to the cans similar to the primarie one. Should be easy to open with the correct seal.
The can's copper tube will have to be blocked.

Looks like if my setup is working similar to mechanical 2ndaries. This operating rod system is still sold on E-bay once in a while , eliminating the vacuum pods. Unfortunately, the 2ndarie carbs have no accelleration pump , hence will bock when depressing the gas pedal.

Again, thanks for helping and brgds. Günther

 

Hi

Pics well received. My pods look exactly the same except for this copper tube that's been added.

I unbolted the pod and as we already knew, the hole to the carb was blocked off by a piece of cork instead with a O-ring.

Seems to be easy to get it all back to normal.

I am sure I will have more questions about this setup as I go along overhauling and installing it. Hope I don't go on you guy's nerws too fast.

Günther

 

I'd love to see a really good close-up of that solenoid and bracket, Tom. Any chance you want to part with it?

Hans