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I have driven my car to a car show and had to sit and move 10feet at a time for a peroid of about 15 to 20 minites. The car started stalling and was hard starting till I finaly could park it. I had the vacume tank rebuilt 2 times both times they found problems. the engine temp was about 165 degrees I opened the hood and noticed that the fuel filter between the vacume tank and carb was empty and bubbles were streaming up from the bottom off the fuel bowl like you would see in the bottom of a beer glass. I also notice other packards with asbestos covering on the exhaust pipe my car dose not have this. should it have that if so were can I buy it. Also I will include several pictures if you see anything wrong let me know. Also the fuel hose in pictures looks close to exhaust but its 4 inchs away.thanks Tom

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This sounds like classic vapor lock, a subject that has been discussed many times before on this and the AACA forum.
In warm weather I need to leave the hood open on my 633 if the car is to be restarted in a short time otherwise under hood heat vaporises the fuel making the car hard to start.
Fitting a shroud around the vacuum tank to shield it from radiant heat from the exhaust manifold reduces vapor lock on these cars. This works best if it is made from polished stainless steel.
I find that adding kerosene to the fuel helps, others have reported that diesel has the same benefit.
I wonder whether the fuel filter you have fitted is restricting the fuel flow given that there is a very low pressure by gravity feed from the vacuum tank to the filter, this might be adding to the problem. I rely entirely on the sediment bowl for filtration and have never had a fuel blockage issue in over 20 years.

Not sure about your year and model but an asbestos exhaust pipe header wrap was pretty standard of most all Packards (except the Twelves I believe) thru at least 1936. See an example on this 740.

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The car in question is a 1929 626 and strangely the Packard parts list for that model does not call for insulation on the exhaust pipe although it is specified for other similar models however I have fitted insulation to my 1929 633 (which is identical). I am sure it helps but I think the main problem is radiant heat from the manifold to the vacuum tank due to the close proximity of the tank to the manifold, hence the need for a heat shield..
I once had an interesting conversation with the owner of an early twin six (they are notorious for vapor lock) and he had tried many things and found the best improvement was fitting a vent to the carburettor float chamber. He stressed that it had to be at least 1/4 / 3/8" dia tube to be effective.
As a matter of interest, hold you ear to the vacuum tank when the car is hot and you will hear the fuel boiling inside, this does necessarily mean it is vapor locking, it is the very low boiling point fractions boiling off. But it shows how close these cars are to vapor locking with a little more heat.

The reason that filter is on there is the fuel tank had been coated before I got the car.also there where other problems with vacume tank.I dont know what was done to the fuel system but the carb kept getting what looked like glass bead particals in it. I feel the filter may be part of this problem like you said but almost have to have it. Over the past winter I had the tank out and cleaned it. also blew out the fuel lines and cleaned carb and vacume tank.Be fore I cleaned the fuel system the filer would clog so bad fuel would not pass through it.I had a question on the vent in the carb did he drill hole in the lid of the fuel bowl how long was the tube?

I also for got to say that 1 problem that they found with the vacume tank was the flapper valve was not closing properly and would not let the fuel drop due to engine vacume leaking through

29tons,

IMHO I'd remove the paper filter element between the vacuum tank and carburetor.

There isn't sufficient fuel pressure from the gravity feed tank to adequately supply the carburetor.

Dave

29tons, in response to your question about the vent, the owner of the twin six had drilled a hole in the top plate of the carburettor float bowl, soldered a standpipe that was routed up a short distance, discharging below the engine. It was not very tidy but the car was a driver not a show car.
The twin sixes have the carburettor mounted in the "V" between the cylinders with the exhaust manifolds running closely along each side making a heat shield a virtual necessity for any significant driving and although our 1929 cars are not as bad I believe that the heat shield is the first line of defence. It can be done neatly but would not suit a show car.
Another method I have used when touring in hot weather is to make spacers that lift each side of the hood a few inches so that air is directed into the engine bay over the top of the radiator instead of being heated passing through the radiator.
This does not look good when driving but in hot weather some drastic measures are needed.
I have driven my 633 in 100 deg plus weather with lots of kerosene in the fuel, a heat shied, hoods raised and it still vapor locked when stopped at traffic lights.
I have now fitted an electric fuel pump that delivers fuel directly to the carburettor bypassing the vacuum tank. It is only for use when needed, I have not yet had the opportunity to test it when vapor locked.

Dear 29:

Get rid of the fuel filter. It is a restriction. If you are having a dirt problem the a filter should be installed before the vacuum tank. The vacuum tank will pull through a filter given the motor is in good condition, but will inhibit sustained full throttle.

If you think the manifold is causing problems you can test by making a heat shield.

Check your compression and motor vacuum. The vacuum tank will cause problems in worn motors and will need to be bypassed using an Airtex electric (available from Hirsch) and a 1 psi fuel pressure bypass (available from McMaster-Carr).

To test the tank, buy a hand vacuum pump and plug the fuel line. The unit should hold vacuum. Next fill the tank via the hand pump to pull gasoline from the tank. If it doesn't fill you have a valving problem. Or an air leak in the pickup circuit. Brave souls can simply suck on the line to fill the tank. (Heavy smokers will probably have some problems.) Those old tank pickups are prone to pin holes as well.

Dirt in the fuel will cause absolute havoc with the vacuum tank, so if the gas tank isn't in good condition that needs to be addressed. (Apparantly those old globe type gasoline stations were pretty good at delivering clean fuel to gas tanks).

You can confirm you have a vacuum tank problem by filling the unit during a no start situation, but do not overtighten the fill plug as the pot metal is old and delicate. Snug with your finger should be plenty.


Hope this helps.

In addition to Tim's good advice there is a lot of information on line on how the vacuum tank works. Its a simple and usually trouble free device and its worth spending a little time understanding how it works.
Vapor lock is not so easy, one of the problems in diagnosing it is that it does not occur all the time. You can drive the car in hot weather and convince yourself you have fixed it only to find that it comes back when the conditions are "right". I have restored 2 633's and the second one incorporated all that I had learnt from the first. On its maiden run of about 2,000 miles it performed flawlessly only to vapor lock on a long steep climb on the last day. A wet rag on the carburettor and vacuum tank had it going quickly but up to then I thought I had the dreaded vapor lock issue beaten. I have since fitted the standby electric pump and it could be a while before I get to test it under actual vapor lock conditions.
29tons,I hope you update the forum with progress on you 626.