Even back in the later 1960s as our '66 NEwport 383 2bbl was becoming a great "used car", it had the "normal" extended crank time to start after a hot shutdown. I went through some of the same trouble trees y'all are looking at for guidance and after talking to some people who had driven Chrysler products and worked on them, it was just what could be termed "nature of the beast" in TX. So we tried to refine the starting techniques from the Owners Manual recommendations. At worst, no "instant start" and at best, just a few seconds longer crank time. "Longer than 10 second" starter engagements caused no starter durability issues, either, from our experiences . . . but if it didn't happen in what felt like a decent amount of crank time, cranking stopped. BTAIM
During these learning times, as this was our first "modern" Chrysler product (after '51 and '56 Plymouth 6-cyls), I watched what other brands of cars did under similar situations. Most started a second or so sooner than our Chrysler did, by observation. No black smoke from the exhaust either, from ours or theirs. Later, I investigated the carb design differences between the Rochesters and Stromberg (our Chrysler had the Stromberg WWC3 on it). "Gotta be something that gets the fuel into the venturi cluster quicker on those Rochesters", it seemed. But no significant issues seemed to be there, hot or cold. Everybody was using points back then (that's all we had!), so that made the ignition system "common" among all cars. It usually seemed that engines with a bit more basic ignition advance started a bit quicker than those without, but our Chrysler was spec'd at 12.5 degrees BTDC rather than less.
When we got the '72 Newport Royal 400 2bbl (with the then-optional Electronic Ignition), it did seem to start better. Other than the ignition system, it had the Holley 2210 carb, which I considered to be an advancement over the Stromberg. But it also had the 8.2 CR and a bit hotter cam than the old 383 2bbl did, if that might matter. Still, it seemed that after a hot "soak", the restart seemed to take longer than similar Ford or GM products. Which was BACK when lead (although in decreasing amounts) was still in the fuel, too.
In the 1990s, in the back of the Chevron website, there was an extensive section devoted to "ReFormulated Gas" (RFG), which had more ethanol in it to combat the low oxygen levels in the Colorado atmosphere during the winter months, back then. RFG was the first "oxygenated" fuel, with ethanol being that oxygenate. MTBE was another oxygenate that seemed to work just as well, but was known carcinogenic. When that "battle of the best" went to court, the court decided to basically split the mix of ethanol and MTBE at almost 50-50, so the mix of oxygenates became federal law. UNTIL . . . minute traces of MTBE were discovered in many municipal ater supplies several years later . . . from rain and similar. So the legislation was amended to make ethanol the main oxygenate. Over the later years, "bio-butanol" was another oxygenate which caused NO automotive fuel system problems, ever at 15% concentrations and also had similar CO2 reductions as E10 fuels, but it never seemed to get the support it needed, for some reason, although it could be built in ethanol plants which could be converted to produce it. BTAIM.
Some operatives, in particular states determined that by lowering the Reid Vapor Pressure of the gasoline that evaporative emissions could be decreased, too. SO . . . no universal ethanol'd fuels. In the back of the Mobil website, there used to be a map of the United States and the various types of fuels required in the respective areas. With the major specs denoted by various colors. LOTS of variations! Plus LOTS of areas where E10 is not needed, but due to distribution networks, is probably the dominant fuel available.
In the several websites which map the availability of ethano-free gas, it should be noted that most are near marinas. ALSO that most of the non-ethanol'd fuels are of lower octanes than many of our older cars can tolerate (think 87 pump octane or lower). 100 Research Octane unleaded and ethanol-free gas might still be available in drums and/or at some dragstrips (sold by vendors and not the drag strip itself). Storing larger "amounts" of flammable liquids in garages and such can come under local ordinances, I highly suspect.
As most cars are now fuel injected, the issue of hot restarts has seemed to disappear from normal sight. Turn the key, the computer is commanded to do all of the things in order for the engine to start, in milliseconds, and the engine starts and we drive away. Which, by comparison, makes any engine which takes three revolutions to start, "needing work". And that is the world we are now living in, to me. NOT to forget that we are now MANY generations deep into the situation where many techs have only read of "carburetors" rather than having grown up with them. Same with ignition points, too.
So, to conclude . . . the hot restart issues are decades old and just part of the deal with a Vintage Chrysler produict. You can tweak your individual combination of carb, ignition, and fuel supply system and/or use an electric fuel pump primarily or as a booster to help with the "extended non-use starting issues", too. Which is a different issue, but kind of related to, the hot restart issue. LEARN what your individual vehicle likes best, rather than wanting it to do as you might desire! As with so many other things in life, when you both work together to make everything operate as best they can, things get better and more enjoyment can happen.
Y'all enjoy!
CBODY67
