Hot start problem
I have a 65 Chevy Corvette 327 with a 4 barrel carburetor and a 4 speed stick. About a year ago I replaced the starter (and solenoid) due to a skipping problem, i.e., the old starter would sometimes spin without engaging the engine. It never had a problem starting when hot.
About 6 months later I noticed a problem with cranking after the engine was hot. The problem does not immediately occur, if I shut off the engine and immediately restart it, it will turn very quickly and start right up. But, if I wait a few minutes, like filling up at a gas station, the starter will turn very slowly. Pushing the car and popping the clutch to start it works fine. It seems to start easily when pushed this way, even when hot. It will start at 2 ? 5 mph.
I replaced the starter (and solenoid) again last month (another remanufactured starter). I still have the same problem.
In reading up about the problem I found that some Chevy?s have a problem that can be solved by using either a solenoid from a Ford or a Bosch type relay. I tried the Bosch relay solution. Still having the same problem.
The battery appears to be ok. It puts out about 12.5 volts. Cold starts are OK, but not great. It seems like it used to turn faster with the original starter, even when cold.
Hot start problem
Sorry I just reread the original message and decided that my original reply did not fit. Even though you did replace the starter, it could be getting overheated.
You want to make a heat shield from stainless or even cheap steel and attach it to the exhaust pipe nearest the starter. Drill two holes to match the pipe clamp that you buy, put the clamp on, then the shield then the nuts.
Did you take the opportunity a year ago while you were changing the starter to also install a shiny new set of headers?
Whether you did or not, you have what sounds like the classic Chevrolet starter heat soak. The starter will work fine if used cold or immediately after the engine is shut down. If the engine is allowed to get warm then is shut off for about 5 to 15 minutes the nearby exhaust pipe radiates so much heat into the starter that the internal wire windings get so resistive that the starter can’t draw enough current to effectively turn the engine over.
The cure is in a heat shield. That’s the piece of sheetmetal that pleasedodgevan is talking about.
Yup! Your starter is becoming “heat soaked”.
As has already been stated, you need to insulate the starter from the heat of the adjacent exhaust manifold by installing a heat shield. Once you do that, your problems should end.
Thanks for all the advise. I’ll try to install the heat shield over the week end.