56 Olds engine stops after longer driving

Here is the problem:

I own a 56 Oldsmobile convertible, 324 CUI, 1 x 4 barrel carb, dual exhaust, heavy duty aircleaner (batwing), oilbath, Jetaway transmission.

I am driving the car for about 45 to 60 minutes, speeds around 30 to 45 mph and everything goes well.
After that time, normally I am driving home on a street that allows a speed up to 65 mph.

Accelerating is okay, the car goes up to like 50 to 55 mph for a few minutes and then the engine stalls. Revs go down and the engine shuts off.

I can push down the accelerator totally, it does not matter, engine is off!

After a waiting time of about 5 minutes and like two attempts to start the engine again, the engine starts and I can drive home at speeds not exceeding 30mph.
To repair the problem, I changed the fuel pump yesterday, today no change. I got the rebuild fuel pump from Fusick.
My mechanics told me that it could be a heat problem of the fuel pump, but when the engine shut off today, I felt the fuel pump and it was really not more than hand warm.

The ignition coil was not hot either.

Could it be that there is some kind of debris in the carb?
There is an inside coated fuel tank in this car and the coating dissolves slowly so that we had to put an additional fuel filter into the fuel line.
I am desparately waiting for the new tanks that are planned to be fabricated by Fusick, to get rid of this inside coated "problem tank"

I do not know anymore where to search for the problem.
Any ideas? Any proposals from your side?

Sorry for any possible mistakes in the expressions of this posting, I am German living in Germany.

Thanks for your opinions and help.

The_German

 

Sounds like the tank to me.

 

X2, vent plugged?

 

x3 tank

 

What is X2???
Do I miss something?
Thanks for your help!!

 

X2= times two, as in "I concur".

 

Rig up a safe small gas tank to test your theory.

If it still shuts down on that same trip, at the same outdoor temperature, then I would think your mechanics are correct with a vapor lock problem somewhere.

 

Many 50's cars had vented gas caps, which let air in as fuel left. Modern caps don't vent, thus you may be pulling a vacuum in the tank.

 

This happen to me in my '56 Olds Holiday Coupe. It turned out to be the gas cap.

 

I had a 49 olds 98 and when i got stuck on side of road,I would get out and remove the glass bowl see the rust and dirt empty it and be on my way in no time.X3 on the tank.

 

Thanks so much!
What is X3?

 

One more than X2.

 

the other thing to check is the filters, when I first got mine going it would pull enugh crap out ofthe tank to block the filter and cut off the gas to the engine, I pulled and had my tank cleaned and then POR 15 coated it and its been fine since, if worried about the venting try with the gas cap off or loose.