I picked up a 1971 350-270hp . The car starts fine when it is cold but if I take it and drive it till it gets hot and shut it off it won’t start again till it cools down. I am guessing that it has something to do with the starter getting hot. It looks like there is a heat shield between the starter and the exhaust pipe. The battery that is in the car is a Delco but only has 525 CCA’s. I guess my question is do you think that the starter is going bad or would buying a battery with more cranking amps do the trick? Thanks

 

How does it act when starting hot?

Slow to turn or not turning much at all?

 

Slow to turn like the battery is going to die on me. If I let it sit till it cools it cranks good and starts right up. Not sure how old the battery is. I thought about buying the insulating wrap that you can put around your starter or buy a battery that has more cranking amps or both.

 

Based on your description you're telling us that it is having an issue turning over after driving for awhile. Could be alot of things but three jump to mind.

1. Starter could be getting heat soaked and it lacks the guts to turn it when hot. Not uncommon and you can pickup a high performance mini starter for $150 or so, but I would want to rule out a couple of other things first.
2. Ignition is possibly slightly too advanced and when hot the motor is pushing back on the starter. Easy to test
3. Wiring issue from battery to starter post / loose hardware / bad ground. Takes some looking around on the car but heat builds resistance and resistance can result in what you're describing.

Simple checks I would do first.

1. I assume you have the original style of dizzy in the motor? If so I would get the motor good and hot so you'll know it will act up. Then pull the dizzy to coil wire off either the coil or the dizzy cap and try to turn the motor over. Obviously it won't start but this will prove if it's kicking back on the starter from having the ignition timing slightly too advanced if it turns over much faster like it should you found your problem. If it has been changed to an HEI then pull the connector off the base of the cap to kill the power feed.

2. Check your wiring/connectors. Think shiny bright and tight. Check the cable from the battery, to where the ground cable attaches to the frame. Not likely the issue but easy to check and fix. If you see any green puss (corrosion) in any cable/connector either clean it thoroughly or replace it. Pay special attention to the engine ground I believe it should be on the passenger side of the motor and should bolt to the motor mount horn on the frame. Again bright, tight, and no puss. Do the same check on the main battery lead to the starter.

Personally I doubt it's an issue with your battery if it starts fine when cold. Its easy enough to pull it and take it into a local parts store thats worth their salt and they will load test it, but personally like I said if it starts AOK when cold I would be terribly surprised if it's the battery based on what you're telling us, particularly if the car is charging.

 

Thanks, I appreciate your response. I will check a few of these tomorrow.

 

Harvette,
You have headers on that? Heat soaked starters are more common with them than a single pipe off a manifold running next to the starter.

Over the years, starters get replaced. Some people put the heat shield back on. Some people don't.

 

I would look for a PMG (permanent magnet generator) starter like the mini starter recommended above. They do not seem to be as susceptible to heat soak as the original starter. They provide more clearance and less weight. If you buy a high quality one and install it correctly, you will not be disappointed. The important part of the install is to make sure you get the correct bolts for bolting it to the block. Do not use the original bolts. When you decide which starter you are getting, post something on here if you are having problems with the bolts to use. I am sure one of our member can probably tell you exactly what to get. The bolts don't just clamp the starter to the block, they align it so it is in the correct position.

 

If originality is not a concern, switch to a gear reduction starter. I used the starter off a 1996 full size Chevy truck.

 

Any news? Tried anything yet?

 

This a long shot but I put a327 in my ‘58 that had the same symptoms. Turns out the monkey that worked on it before me mixed up all the bearing caps and main caps. Rearranged everything and it purred

 

Starter solenoid. Heat soak is high probability. My big big block had this issue so I replaced with a high torque smaller starter.

Or if your sticking all original, have it rebuilt.