hard starts when hot

[studegary]

I believe the vapor lock is more related to 1940s-60s fuel systems and metallurgy than to, "modern gas". As a high schooler in the 1960s, I worked on farms every summer, in hay and tobacco. Hay work included picking each (rectangular) bale up in the field, and tossing it onto a slow moving truck as it crept by, where another worker would stack it. The hay hauling trucks were 1940s-1960s vintage flat bed, 2-4 ton, with six cylinder motor. We'd start at daylight, then break for a 30-45 minute lunch around noon.

After lunch, we'd all be hoping the hay trucks would start, and each had about a 50/50 chance. Under the hood, most trucks would have 10-20 clothes pins, and tin foil on the lines. If we could get just one truck to start, we'd work with that one, and come back and try the other(s) later, often several times. Most times, we'd eventually get them all running again. Also, there was a 1957/58 S-P Tech Bulletin on alleviating vapor lock on supercharged Studes/Packards. So I believe the problem is more related to technology of that era than anything else. For us still trying to keep them running 50-60 years later, modern gas probably does not help. But the problem was around long before today's gas.

ISTR that Tech Bulletin as being for supercharged engines that ran short of fuel at high RPMs, not vapor lock.
I have owned and worked on supercharged Hawks that were run at high RPMs, probably more so than 99% are now. Installing an electric pump in the rear solved the problem.

[JoeHall]

ISTR that Tech Bulletin as being for supercharged engines that ran short of fuel at high RPMs, not vapor lock.
I have owned and worked on supercharged Hawks that were run at high RPMs, probably more so than 99% are now. Installing an electric pump in the rear solved the problem.

The TB I referred to called for running pure water in the radiator, since pure water was said to make the motor run a few degrees cooler. It may have not been specifically for SC motors, but it was 1957/58 vintage, and addressed vapor lock.

[acolds]

copy of service bulletin for supercharged Golden Hawk and Clipper overheating

[JoeHall]

copy of service bulletin for supercharged Golden Hawk and Clipper overheating

Thanks. Was hoping someone would dig up that bulletin, since I was too lazy. Could you please type the content out? I cannot read the attachment, even with my, "new" eyes. LOL

UPDATE: Nevermind, I dug it up. It only addresses overheating and says nothing about vapor lock. It's all related, but I shoulda used a disclaimer like, "IIRC".

[Jeffry Cassel]

I was told that a gallon of Diesel per 10 gal of gas will help. It probably does but makes for smokiness! The latest I heard was one quart per 10 gal. Could help a little. Did you know it costs twice as much to make a gal of ethanol than it does to make a gal of gasolene.

[studegary]

The TB I referred to called for running pure water in the radiator, since pure water was said to make the motor run a few degrees cooler. It may have not been specifically for SC motors, but it was 1957/58 vintage, and addressed vapor lock.

It appears that we were referring to two different bulletins (for two different problems).

[doofus]

Found a second spacer, about 3/8 thick bakelite. they came under the old Reo engined Studebaker 2 1/2 ton military truck's. Luck Doofus

[5brown1]

A service bulletin for Golden Hawks specified drilling a 1/4 hole in the center of the choke plate to help with hot starting issues. They used the Stromberg WW carb which may be the same as yours.

[TWChamp]

I'm wondering if the crap gas isn't boiling over and flooding your hot engine, which makes hot restarts difficult. That's the problem my 1950 Champion has, so since I am now using an electric fuel pump on it, I turn off the fuel pump a minute or two before I turn off the engine. This keeps the gas lower and prevents boiling it over into the intake manifold.

I still haven't tried adding diesel fuel to crap gas, but will give it a try when I get stuck having to buy ethanol laced gas.

[thom]

I adjusted the choke before starting it first thing this morning and we drove it some today, with several stops and restarts. It did fine today. I was prepared to install the electric pump but I think I will give it a few more days and see what happens, although the temps here are forecast to be quite cooler for the next several days.