A defective coil wire will do it. Remember it "works harder", about 8 times harder, than the plug wires in fact. Sounds like you've got a few things going on to keep you busy. Ignition coils themselves get hot, especially considering old school systems have a fixed dwell period. Slower speeds, or idle, should therefore show increased temperatures. How hot is "too hot"? Well they ordinarily dissipate about 70 watts or thereabouts. Check carefully the ohms resistance of the primary circuit, this is the total of the ignition coil primary winding, associated wiring, ignition switch, connections and ballast, if any. It's sort of like Goldilocks and the Three Bears, "too hot" or "too cold" is not what we want. The shop manual lists the specs for the ignition coil and total resistance, current, and voltages. If the primary circuit is getting too much juice for whatever reason, it will cause problems sooner or later.

"Late" or retarded ignition timing will cause the situation you describe with the exhaust manifolds. If ignition timing is way off the beam, they will even start glowing red hot in broad daylight in an astonishingly short period of time. This happens because fuel burning is not confined to the combustion chamber where intended, but is now after burning in the manifold itself.

The good news is you are making progress nailing down the issues. Get the ignition squared away, get the ignition timing squared away, and get the carburetor fuel mix squared away so the plugs aren't fouling out, and it will probably seem like a completely different engine.

Thanks, Tedster, for your input and encouragement.  Can you recommend what type of diagostic equipment I should have in addition that that I previously mentioned?

I will go back to the car tomorrow when its cooler and see if I can get it to idle smoothly enough to set the timing and idle mixture screws.  Also will check the coil temp to see if the nearly seperated ignition wire may have contributed to my sense that it was too hot.  I am kind of a dunce when it comes to multi-meter operations but will attempt to check the the ohms, volts, and current at the coil.  Fingers crossed!

Honestly the best piece of diagnostic equipment you can have is the one between your ears! The thing about carburetors, is they are very sensitive to the overall state of engine tune or condition, and they will simply not respond to adjustments the way they should, if the ignition or ignition timing or valve timing are defective, or there are any vacuum leaks. This is why carburetors are often mistakenly blamed for poor performance or rough idle and other problems.

I'm not the greatest engine tuner guy in the world, so what I do, where I've had the best results is let the shop manual or general Tune Up manuals walk me through it one step at a time, in the 1,2,3 methodical order or steps laid out. They set the troubleshooting guide or "tree" the way they did for a reason. Everybody always wants a shortcut direct to "replace this part" or "tweak this screw to 1.5 turns" and everything drops into place. Start from the beginning and test test test, measure measure measure!

All of that stuff has the factory specs laid right out in the manual for you, for psi, (compression), inches of mercury, (vacuum) and volts, ohms, amps, oil pressure, fuel pump pressure, RPM, temperatures etc. I might not yet fully understand how some component or group of components is supposed to work exactly, but armed with the right manuals I can usually tell right away if it is out of range or not working as advertised.

If any specific basic test or check or voltage (or whatever) in the Tune-Up section isn't satisfactory, doesn't meet the spec, stop right there and find out why, and fix it before moving on, because it won't ever run quite right. A good, sharp tune is mostly making sure a whole bunch of operating points and adjustments meet or exceed factory specs. With vintage engines a lot of it is oftentimes simply just undoing past mistakes and getting it setup back the way it was designed & supplied according to Hoyle.

Tedster, I am back at it again.  I checked the coil function by holding the coil wire about an inch from the exhaust manifold while cranking the engine using a remote starter switch.  The spark was strong and regular, just like lightning.  After leaving the ignition switch on for about 90 seconds there didn't seem to be any excess heat in the coil.  I have no idea how to do further coil tests using my multi meter but the strong spark seemed to indicate that the coil is good.

I then attached the timing light, pumped the throttle a few times, cranked the engine and started, had to pump the throttle a couple more times and it died.  Pumped it once more, cranked it and it started (very rough idle with occasional popping at the exhaust), fiddled with the throttle to keep it running at a higher idle (1000 rpm), still very ragged with more exhaust popping.  The timing light was applied then and it indicated that the timing was correct even thought the idle speed was excessive for a really good test.  The vacuum advance line had been previously disconnected and capped.  I tried reducing the idle speed for a more accurate reading with the light but it refused to run well at the reduced rpm (500-600) and the tach and vacuum gauge were bouncing quite a little, with the vacuum gauge ranging from 15 to 19 inches.  The engined died again as I was attempting to reduce the idle, tach was bouncing from about 400-700 rpm.  The coil did not heat like it had previously done when I discovered and repaired the faulty wire connection.

I have read several other forum entries on this type of problem and some responders suggest that the timing chain may have jumped.  This something beyond my realm of expertise and I don't know how to check it without actually inspecting the chain for allignment with the sprockets.  Obviously valve timing relates directly to spark timing so I would assume one would look under the valve covers to see if the lifters are doing what there are supposed to at the proper time.  What do I look for and how do I determine that the intake and exhaust valves are shaking hands with the distributer?

Sorry to be such a pain.  The car had been recently running (until it quit) the best it had since I got it on the road in 2015.  What would cause it to jump time at the chain?

The idle mixture screws are still set at 1 1/4 turns and the point gap is still correct.

That happened to me back in the early 70s with a poorly maintained I-6 Merc.(chain jump).  Likely worn chain & sprocket was the cause (?), but while it was running ok (until it just  wouldn’t start one day), the timing could have been so retarded from point wear, a back-fire might have been the ‘last straw’ (?).

6 VOLTS/POS. GRD. NW INDIANA

In the past 20 years, I have seen a jumped timing chain proposed as the problem many dozens of times.  Not once can I remember it actually being the problem.  Since you did get the engine running over 1000rpm and timing was good, that's not the problem since a jumped chain would directly affect the indicated timing (it would be bad by quite a bit).

Is the tachometer that you are using the tach/dwell meter and is it on the correct setting for a V8?

Earlier in the thread, you said you re-set the timing.  Was it bad then?  That could suggest an issue and may render a current "good" check bad.
You also said that you re-set the idle screws.  If that is by the book, then that is a starting point and what your engine needs could be different.  Incorrect adjustment here can prevent it from idling well or even at all.  This situation would require more throttle to open the throttle blades in order to activate the primary circuit to get fuel and "idle" but at elevated speed, although it should run smoothly once the primaries are activated (you said it is very ragged).


Lawrenceville, GA

You mentioned that you couldn't read 6 volts through a plug wire which makes me think you have carbon core wires. I had a '65 Galaxie that had a horrible miss after running awhile. The carbon wires were the culprit, My neighbor found it with a Sun Scope he owned. You haven't mentioned replacing your wires. If your wires were copper you shouldn't had any problem reading 6 volts through it. If you do have carbon wires with a lot of age on them I'd replace them with something metallic. You might have resistor plugs anyway. I haven't been able to buy non-resistor plugs for years. Resistor wires  with resistor plugs on 6 volt ignition is a bad combination in my opinion. Just a thought.

Something is wrong with your fuel delivery system.

"FREE SAMPLE"

Thanks for responding, Charlie.  A little background info for you so you know the history.

Restoration was completed in 2014 including a complete engine rebuild.  The car has run well for several years racking up about 4,000 miles.  I diagnosed some distributor problems about 250 miles ago and replaced the dizzy and changed the 1954 teapot with a newly rebuilt 1955 teapot from the Hotrod Reverand.  Minor tweaking with fuel and ignition over the next 100 miles and the following 150 miles have been flawless.  The best it has run since 2014.

As I previously stated, on my last outing of 50 miles, I lugged it down in 2nd gear turning into my driveway killing the engine.  Thats when this mess started.  I pushed the car into the garage and I could not get it to start.  To reiterate, following that I pulled the distributor and replaced the condenser and relaced and gapped the points and checked the wire connections inside the dizzy.  Then I cranked the engine around to TDC compression stroke (finger in #1 spark plug hole) and re-stabbed the dizzy making sure to align the rotor to #1 on the dizzy cap which I also had just replaced and then set the dizzy shaft so the points were just beginning to open so the timing would be close to correct.    I cranked the engine using my remote starter, pumped the throttle at the carb linkage, and it started.  However, it would not idle smoothly - engine was shaking (probably from misfiring), driver side exhast at tailpipe was popping irregularly, and I could keep it running only by manipulating the throttle trying to maintain an idle.  The tach/dwell meter (properly set) shows the engine speed to range from about 400-700 as the engine shakes and exhaust pops.  The vacuum gauge needle also fluctuates from about 15 -19 inches.  I am unable to get it to smooth out by a minor twist of the dizzy in either direction.  I currently have the curb idle adjustment screw quite advanced to keep it running at all but it continues to shake and pop.  The timing light shows that timing is close but the engine speed is too fast to see clearly.  The repair manual states idle speed at 475-500 rpm but the engine will not run at that rpm.

You just stated that you replaced the distributor cap.  Are you absolutely sure the wires are in the cap in the correct firing order?  Sounds like crossed plug wires to me.  The wires didn't cross themselves when the engine died, but may have become crossed when the cap was replaced.

John - "The Hoosier Hurricane"