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My experience with vapor lock is confined to the Packards of the 1920's where it is a serious problem here in Australia in hot weather and long climbs. I have been told by a fuel company engineer that the problem in our old cars will be much worse today than many years ago. The reason is that modern fuels have a lower boiling point to suit the modern high pressure fuel injection systems. The high pressure raises the boiling point well above the engine bay operating temperatures so that it should not be a problem in fuel injected cars.
I live with this problem by adding up to 10% kerosene to the fuel in summer, as recommended by the fuel company, I have tried diesel but it was not very effective. An electric fuel pump bypassing the vacuum tank (pre-fuel pump) would be a better solution.
My 1922 Packard has the original "Packard Fuelizer" carburetor which incorporates a small combustion chamber to heat the fuel, presumably to aid vaporization in cold weather. A small amount of fuel is bled into the combustion chamber on the carburetor where it is ignited by a glow plug operating from a separate coil. The mixture is adjustable and the hand book describes the procedure and correct flame temperature. Obviously this is not used today.

Dave, I think that's an accurate description; remember that the octane rating of gasoline in that era was probably 60 or less.

Boiling point of gasoline 100-400 degrees F ??????

engineeringtoolbox.com/fuels-boiling-point-d_936.html

Gasoline, being a blend or mixture like other distilled products, does not have a single boiling point - there is a cumulative curve of how much of the total vaporizes at what temperature over a wide temperature range. The weight vs temp is a S-shaped curve

Gasoline is a mixture and thus doesn't have a single boiling point; it's a mixture of hundreds perhaps even more individual hydrocarbon molecules, each with it's own individual boiling point. Hence the fact that it has a boiling point "range", not a single number. When you see gasoline boiling, you are seeing the lowest boiling component boiling.

If you were to put gasoline in a distillation column and begin to heat, you'd see the boiling point rise gradually as the lower-boiling fractions are distilled off, leaving the higher-boiling compounds behind. Crude gasoline of many years back before the advent of efficient "cracking" (which sort of broke the larger, higher boiling molecules into smaller, lower boiling ones) no doubt had a much broader boiling point range than today's products. Actual data would be interesting.

Overly simplified description.

Thank you Gentlemen.
So then what i need now is a safe way to boil some E10 gasoline from my local area and measure the temperature at which i first start to see it boil.

I'm wondering if an electric hot plate set up OUTside and 50 feet away from everything would work???? I could just use a rather large pot to be sure the hotplate coil is well covered and not exposed.

Generaly, is it reasonable to assume that alcohol boils at ABOUT 170 degrees F ????? Much of a boiling point range on alcohol????

Is it reasonable to say that if all the rest of the E10 gasoline mixture has a HIGHER boiling point then the alcohol would boil first????

THen could it be that the vapor lock everyone is experienceing is the ALCOHOL content of the E10 fuel that is boiling and NOT the other ingrediants of the E10 gas???

Packard Hoods (Bonnets).
What is the last year of Packards that have an engine hood that can be easily removed with little or no effort??? Some of them just lifted off???

This type of hood was introduced with the 1941 Clippers and continued through the 1950 models.

I'm wondering if an electric hot plate set up OUTside and 50 feet away from everything would work???? I could just use a rather large pot to be sure the hotplate coil is well covered and not exposed.

NO, don't do it yourself, it can be dangerous!! Gasoline has a very low flash point. Why not talk to a high school chemistry teacher and have it done in a school under supervision with the right equipment. Besides, they'd probably love to have the little project.

Boiling point of ethyl alcohol is 78.4 centigrade, or about 172 fahrenheit. It has a single, sharp boiling point because it is a single chemical compound. Merck's index gives the following for commercial gasoline circa 1976. Initial boiling point 39 deg. C.; after 10% has been distilled off, about 60 deg. C.; after 50%, about 110 deg. C.; after 90%, about 170 deg C., with a final boiling point of about 204 deg. C.

I'm really dubious about your theory, but don't let that dissuade you from gathering more facts.