VAPOR LOCK

[Packard enthus.]

I see some folks are still puzzled about the vapor-lock issue.  Well-discussed in this and other sites down thru the years,  but apparently, still some folks who "dont get it" about basic physics and the boiling point of modern gasoline. 

 

Anyone want to discuss ?

[JFranklin]

I never experienced vapor lock until they started pushing E-10 gasoline. 

[Packard enthus.]

3 hours ago, JFranklin said:

I never experienced vapor lock until they started pushing E-10 gasoline. 

I am not sure there is a connection.   We know from Packard engineering discussions in their tech. manuals of the early 30's,   that as the oil companies raised the Reid Vapor Pressure of motor fuels (to enable easier starting in the winter)....vapor lock became more of a problem.  Perhaps someone with a better understanding of fuel chemistry can come in here and tell us whether the addtion of alcohol significantly raises the Reid Vapor Pressure of motor fuel.

 

I note with amusement in another forum some fellow is claiming that "straight eight" cylinder Packards never have vapor lock - its only the V-type motors that do"

 

Of coruse that is utter nonsense - even a cursory review of either SAE or Packard tech. manuals going back to the early 1930s make it clear the problem is keeping fuel from vaporizing in the fuel lines.   The size, type, and cyl. layout of any given motor is irrelevant to the problem of vapor lock.  What matters is the placement of the fuel lines,  and what sort of device brings the fuel to the carb.

 

My primary concern about using E-10 gasoline - well...two concerns.....first...some tech. discussions suggest it causes gasoline to 'go bad" sooner;  that the "shelf life" is only 30-45 days.....and secondly,   it can cause non-metalic fuel tanks and older rubber parts to start disintergrating,  making for an explosion hazzard.  

Edited October 12, 2023 by Packard enthus. (see edit history)