I am having problems with my 64 overheating per-say. I have had the engine completely rebuilt from the ground up including dipping the block, new cam, rings, valves, heads redone, lifters, etc. I have replaced the fan with a direct fan, (no fan clutch) and when you idle for any period of time or drive anywhere and shut off the engine..it will not restart until it sits for about 30 minutes. Almost sounds like it's vapor-locking. I may point out that the radiator is not boiling over but the gauge will show almost to the hot mark to the right...I have tested the gauge like the service advises and it seems to work perfectly, but when I was driving the car the other day the gauge was acting pretty eractically. moving back and forth and not really holding steady. I have a 165 thermostat installed, the block is clean with a 50% mix if antifreeze/water. When I try to restart, the engine will just drag like the battery is dead and the battery is fully charged. I have replaced the intake from which I learned when the heat riser valve gets stuck open it can create this type of problem, but has done the trick...Help? Please help. I am at my wits end...maybe I missed something?
Not starting for 30 minutes does indeed sound like vapor-locking, which it could well be.
The starter dragging when the engine is hot could be that the engine is still tight because of the overhaul, but when I last had that problem on a '66 429 when it was hot, it was because the starter was in need of an overhaul. Bystanders said my timing was way off, I of course, knew better. Once overhauled the starter spun that engine like a top.
Check in order - battery cables & ALL connections - especially ground. If no problems found, odds are it is the starter.
Check the condition of the battery cables, grounds, to include the large ground strap at the start to frame rail.
What carb are you running? The stock carb can run very lean and still sound and idle good. I put in a air/fuel ratio monitor to test and tune my 63. Pull the o2 sensor out and cap the bung when finished. Or take it to a garage to adjust the idle with an emissions machine.
The water pumps have been coming in new, already bad. the clearance between the impeller and pump body is out of tolerance.
When E-10 fuel became the norm in my area, my 63 started running hotter than normal. Enriching the fuel mixture helped to reduce the issue. Heat soak after shut down is also an issue, be sure the heat riser is functioning and the floats in the carburetor are at the proper level. Some carb folks recommend lowering the floats a little when using E-10 fuel to help with heat soak boil over after shut down. E-10 can cause vapor lock issues, the heat insulator is installed under the carburetor?