Get a high torque Powermaster starter from Summit.
End of issues

 

Heat soak just increases the resistance of the windings and it simply takes more juice to do its job. It’s been an issue with headers forever. A good heat shield helps a lot.

one of many reasons I hate headers, but run them anyway.

 

1. Be sure the copper clad aluminum ground wire has been replaced at the frame/block.
2. Use a starter from a 2000 ish gm truck, the optional permanent magnet & gear reduction unit. I'm using one in my 78 with headers. I used one in my Syclone for 2 decades.

 

I have a high compression 427 big block and it was hell on factory starters when the engine and starter were hot. It would cool off and get better, eventually.

With long tube headers the problem seemed less frequent. There is a lot of MASS in them there exhaust manifolds... The one most effective swap was when I installed a Gear drive starter. That little starter was designed for up to 15-1 and works just fine on my engine.

Later on I learned that some Holley devices had the ability to retard the timing WHILE the engine is cranking and this "unloads" the starter motor even more. I have mine pulling 20* of timing during cranking and it cranks my HC 427 like a MOPAR Slant six.

Today some of Holley 6AL boxes and EFI systems have this feature built into them, you simply have to set it up to make it work. Pulling timing would probably allow you to stay with your present starter. It is safe and a very effective way to crank a high compression engine over. There are NO heat issues with my 427 running the high compression during starting. I can start it or stop it whenever I want and it works great.

The Battery cable size is truly an important item. There are probably a lot of "universal" cables out there being used for the wrong purpose on a Corvette.

"You have to have the Cable if you want to pull the Current"!

 

The problem is heat. All of these suggestions work sometimes. In my case the solution was to install the gear reduction starter from a more recent engine. They are vastly superior to the old style starters and shave about 10-15 lbs. off the car. I used the starter from a 1996 full size Chevy truck.

 

Overkill in my opinion. Buy any mini starter from a 96-2000 vortec and a kill switch on the ignition. Get it turning switch on fire it up. $100.00

 

Has anyone taken Lars' advice (post 9) and checked and or upgraded the positive cable to 1/0?

 

I just upgraded to a modern high torque starter on my 67 big block and I am thrilled with the results. I have owned the car for 53 years and it has never started as well, hot or cold. I did save my old style starter just in case my estate sells the car to an NCRS type.

 

I'll throw this out there. I had the hot start problem for 20+ years. went through starters put bigger cables in the car etc. nothing worked. pretty embarrassing when your starter grinds after getting gas. ended up with an ignition kill switch for years. spin the engine then flip the switch. couple years ago I had the engine out and I figured I would put a new engine harness in since it's the easiest to install and it would not hurt to replace the 52yr old harness. well after installing the new harness no more starter problems. probably 52 yrs of heat broke down the wires that attached to the R & S terminals on the solenoid.
Pat