Classic/Antique Car Repair: vapor locks, electric fuel pump, vapor locks


Question
Both my 41 Stude (6) and my 56 Packard (352 V8) seem to have the same
problem:  start with a prime, run well until warm or hot, and then just quit for
the day or so.  Nothing will coax them to run once they quit.  A day or so
later, the pattern repeats.  Have overhauled carbs.  No difference.  The 41 has
an electric  fuel pump (along with the cam pump).  If the electric is left on too
long, there is much leaking from the camp pump.  Do I need to get the fuel
lines away from the heat of the engine?  Should I install additional cooling
fans?  The Packard will run 5 or 10 minutes at a fast idle, and them simply
quit, just as if the ignition were turned off.  Hope you can help.  Thanks!

Answer
Just off the info you gave, I would not think the problem is fuel related. Haye you checked for spark with a meter once it dies?  What voltage does your coils put out?8000, 10000, 15000 volts?

Does the coil input maintain voltage to whole time?  What does a vacuum gauge show about your valve condition?