I'm starting to think she hates me. The lady? No, the babe in the garage. Here's the facts: totally rebuilt restored honey. Never an accident, original engine, tranny, frame, rear end, etc., the whole enchilada. 327/340, 4spd, no AC, 180°thermostat. Engine rebuilt 60 over. Essentially less than 500 miles on rebuild where everything replaced and done right. Cold start no problem runs great, engine temp stays 180 or below. Use high test Mobil and octane booster due to high compression demands and boost to factory preferred octane rating. The other day, I turn her off and jawboned for 30 minutes and she becomes that girl in the Exorcist. Hard start, won't idle and dies, can't accelerate and it chokes, gags, misses, won't literally get out of its own way. Hard to even get it off a dead stop. Just limps up to speed and have to run it at at 3500 in second to get it home. 7 miles of hell and nails down to the quick. Twice now. Third time will not be the charm. Got it home today, pulled off air cleaner and the accelerator pump is spitting fuel fine and dandy it appears. Points look fine as do rotor and cap as they should with a few hundred miles. No carbon tracking in cap. No popping back thru carb. Both days this happened have been above 88°. What is a poor boy to do (next)?
And why the handle for this newbie? Dear dad, now 33 years passed, was 15 in 1922 when his dad died at the desk of New Departure in Bristol, CT. (It was acquired by GM and made bearings as many of you know. And helped win WWII. Later it merged with Hyatt Bearings to become a New Departure Hyatt.) Well they put my dad to work sweeping floors after school in 1922 to support his mom and younger brother. He retired 47 years later in 1969 and was in charge of the entire plant's inventory and production. It was the largest manufacturing facility in New England at the time. Those were different times when employees were family and they were looked after! Also, I learned to drive a stick at 16 on a brand spanking new 68 yellow/black/black 350-300, 3spd that was awaiting my brother's safe return from Nam as a front line medic. All irrelevant but for understanding my allegiance to the iconic muscle car. Oh yeah, I learned to drive with a Corvair Monza. Appreciate the suggestions to help this GM brat.

 

Welcome to the CF! I would consider the gas boiling in the carb. Have you verified engine temp with an IR gun? I would also look at the coil and read its numbers and last check your ballast resistor. Sounds strange, but they can be a problem. Dennis

 

Phenolic spacer? Heat riser wired open? Intake passage blocked off?

 

Boiling yes
How about boiling at the mechanical pump?
I have seen fuel filters with a vapor port
just watched a video on the very same thing
John

 

Starter motor

 

It only does this after warming up and the choke is off and at idle? Did you install a brand-new hydraulic cam and lifters? Did you rebuild the engine? What oil are you using?

 

I appreciate all the suggestions! Some of them sound pretty plausible for solutions. I'm pretty sure it's the fuel supply somehow. That conclusion is reached because it runs absolutely perfectly when it's cold right through warm up and operating on the highways and byways. It's when it is shut down and sits for a bit that the problem occurs. I'll report back after this puppy is trained, so to speak.

 

I asked because a flat cam has many of the same symptoms.

 

Are you still in the Bristol Ct area? I grew up a few miles from New Departure and am still in northwestern CT. I also have a 62 340hp and could lone you a carb or coil to try out to see if that is related to your issue.

I would also look at the fuel line routing to make sure it isn’t getting excessively hot.

Give me a private message if I can help, Also you shouldn’t need octane booster, just run shell, Mobil, or Sunoco 93. Dan

 

Is the fuel line to close to the engine causing the gas to get hot?
As in response #1 check the engine with an IR gun.
Good luck.

 

Normally, I would guess the timing needs to be checked if the engine is hard to start hot, but runs well after starting. In that case, I would move the initial timing back to 4 or 6 degrees BTDC and see if the starter spins the engine easier.
It sounds like your issue is now cold or hot. That said, I would start with a basic tune up, especially checking the dwell and timing. The screw holding the Points does slip and the dwell is critical on these old engines. Check spark plugs to see how they are burning. Check the wires with an induction timing light to see if one is firing irregularly. Also check them with your VOM meter for continuity. Look for cracks and arc tracks in the distributor cap as well as on the rotor. Check the ground wire on the point plate.
If the points, condenser, cap, wires, check out, then look at the fuel pressure, fuel filter, and fuel levels to see if you are flooding or running lean. Use a vacuum gauge to determine if there is a vacuum leak, maybe the carburetor sucked in a gasket. Check the fuel in the tank for debris and rubber hoses for cracks that allow the pump to suck air. Check the metal fuel line for damp areas indicating a pin hole or crack.
That's about a good start.

 

Is the fan clutch good? Fan working as it should?