At one point in time, I'm sure most C3 corvette owners (limiting it to just corvettes) have experienced the heat soak issue. For those who have who do not know what it is. (not trying to insult anyone's intelligence)
The result is when you drive your corvette and turn off your engine when you reach your destination, then return 5-10 minutes later, your vehicle will barely crank or in some cases don't crank at all and you have to wait until the solenoid cools before your vehicle will fire up and you are on your way. Is this phenomenon fact or fiction. If fact what can be done do prevent or "cure" this problem.

 

Connections at solenoid are loose or a crappy solenoid. Battery terminal ends are bad. loose , corroded. Starter rebuilt or checked by someone who does it correctly with good parts. The ignition coil is getting to hot to work properly. The timing is off because you are trying to time your engine to a mark on the harmonic balancer that is not correctly positioned due to having spun a bit. I myself use a vacuum gauge. Compression??? is it good or bad--- have it checked. Exhaust ??? Headers, use a starter blanket or make your own heat shield. Exhaust leaks? Distributor shaft play?? Timing chain play? Fuel lines going to the pump are getting hot due to the headers/exhaust and may need to be protected. assuming that they have been altered in some way other than factory. I haven't seen your car ---so I am just passing along past experiences. The carburetor is not holding a prime and the fuel pump may be bad, once again, I haven't had a chance to crank your car cold to see how it operates and then while it is hot. Intake leaks and exhaust leaks? Carburetor vacuum leaks? Carbon on valves and pistons. Many of these issues listed are possible in causing the engine not to start quickly eventhough the engine spins over quickly. Check the wires at the starter for proper insulation and routing away from heat .

 

Fiction,

Otherwise every old car in the country would never start including all my own junks. Its actually a weak argument of a persistent hard cranking problem and normally a incorrect analysis by inexperienced back alley mechanics.....

 

I believe there are 2 different "heat soak" issues.

1- the no click from the solenoid issue
2-the very slow turning over when hot-mostly big blocks

On the no click of the solenoid come back in 10 minutes and it starts issue I know that is absolutely true. I have proven it to myself by removing the starter and replacing only the solenoid. I then put the bad solenoid on another car that was starting just fine and all of sudden it developed a heat soak no click issue. I have had many many cars in that I have replaced only the solenoid and fixed the problem.

On the slow turning issue I've found on cars that have a good starter that replacing the old cables with new usually improves but adding a ground cable from the starter all the way back to the battery cable also improves the slow turning even more. If you dont run a long ground then make sure the ground at r motor mount is good and connections are clean and tight.

Yes worn brushes and worn bushings will cause slow turning-but thats just a bad starter.

 

my vette (427 big block) had this issue.

bringing the cooling system up to par, a new battery, a new battery ground cable, and setting the base timing correctly have made it so the car always starts... the situation can still be a bit scarry.

i also tried fitting a reduction starter, but it didnt clear the exhaust so i went back to a heavy duty regular starter.

 

Do a search as i have answered this many times. Look in my profile pix at how i fitted up a JC Whitney shield and it works great. No problems starting after >100*F stop and go traffic. If you need more specific info PM me.

Good luck,
cardo0

 

Advanced initial timing can lead to starter drag. I use a high torque mini-starter in my L36. Having said that, a good stock starter should do the trick, because these cars did fine when they were new. Anyways, the mini-starter works great for me.

 

Heat soak is very real with non-stock, bigger engines, and exhaust headers. I had problems that were cured with a remote (Ford style) starter solenoid.

 

....This is fiction too...

Another blame the starter when you can`t find the real problem. Ford uses the same switch on top of the starter for there large 429 and 460 engines in both trucks and large cars. And I personally use large BB Chevy engines with headers and stock cranking components.

anybody want a good starter? i`ll sell them one.

 

Some call this fiction, others do not. Many of us have experienced it, so there is at least some evidence of its existance. One of the problems is cheapo rebuilt starters. I used to eat a starter almost every year. The mini-starter was one of the best investments I ever made. That little thing cranks like crazy. Saves batteries too... Anyways, that's my experience.

 

Who's blaming the starter? It's the solenoid.

What happens when you have a heat soak issue is that the solenoid is getting hot increasing the resistance across the coiled wire inside (which consists of a lot of turns of small gauge wire) which increases the amperage needed for the solenoid to activate. Even Chevy knows about this since stock Vettes come with a heat shield to help prevent this from happening. By now, most of the stock heat shields are long gone...

 

Chevy put on adequate starters. This a common "no click" condition. Simply worn out, probably accelerated by excessive heat.

 

An old racer trick was to add a wire from the positive battery post through a push button on the dash to the hot starter post. This gave the starter a jolt of juice when it would rather sleep or drag from high resistance/low current.

In life, all you want to do is make it to the feature but you gotta make it to the next heat first.