[Interceptor]

OK so Spring has sprung and (self) checked all suggestions above and still no start when hot. Headers are changed and wrapped and heat shielded and the starter is cool enough to touch when no-start condition exists. So, it does not appear to be starter heat soak -- something else gets too hot. Open to more suggestions.

[Interceptor]

Originally Posted by hal101

yes it sounds like a starter prob but i would try disconnecting the HEI next time you have this prob and just see if it cranks better

You mean disconnect the vac advance?

["QUICK-SILVER"]

Originally Posted by Interceptor

You mean disconnect the vac advance?

He meant unplug power to the distributor. Then see if it turns over with ignition disabled.

If it does turn over...Would still need to do the cold and hot amp draw test to see what's really going on.

This thing not turn over at all or barely turn and grunt to a stop?

Grunt to a stop: could be too much initial timing OR starter just not strong enough to do the job for some reason.

Bought a rebuilt high torque starter many years ago. It wouldn't turn the engine over when hot. Tested perfect at the parts store. New battery, new cables, same problem. Opened the starter up and found a small armature in a high torque case. Needless to say, it was weaker than the weakest starter ever made for Pontiac engines.

Clay

[Interceptor]

No change with HEI wiring disconnected. Couple of clicks and a whining sound from the starter, maybe moves a little but not even part of a turn.

Doesn't matter whether timing is at 0, 12, or 22 degrees initial.

Doesn't matter whether the starter itself is hot or not. Engine doesn't even have to be blazing hot, just running for 5-10 minutes will do it.

The solenoid just engages the drive and closes the starter circuit, correct? Drive engages and starter turns a little so I think the solenoid is doing its job.

I guess it's off to a shop to do load tests etc.

["QUICK-SILVER"]

Solenoids will/can kick the drive gear out and still be bad. The copper lugs or disc can be worn out and not send power to the starter motor. Or send very little power to the motor. Those can free rev/bench test fine but not make enough power to turn the engine over.

Same thing can happen with poor brush contact. From brushes worn out, broke tension spring, wires screwed to brushes came loose, etc..

Clay

[Schurkey]

Originally Posted by Schurkey

I would put a starting/charging system analyzer on that vehicle when cold, measure the starter amperage draw along with battery voltage while cranking. Then drive the thing so that it's fully-warm and would tend to act heat-soaked and slow-cranking. Connect the gauge, measure the amperage and voltage hot. Compare the two readings.)

Originally Posted by Interceptor

OK so Spring has sprung and (self) checked all suggestions above and still no start when hot. Headers are changed and wrapped and heat shielded and the starter is cool enough to touch when no-start condition exists. So, it does not appear to be starter heat soak -- something else gets too hot. Open to more suggestions.

Originally Posted by Interceptor

I guess it's off to a shop to do load tests etc.

Yup. I fully expect that the starter amperage draw will not meet specs--assuming the wire on the "S" terminal has proper voltage during cranking.

Just to ask the question...can you turn the engine over when warm by pulling on the accessory belts, or putting a socket-and-ratchet on the damper bolt? This isn't a matter of a seized engine--right? Torque converter clutch not stuck "engaged"?