hard to crank when is HOT

[Nacho-RT74]

It looks my car is becoming hard to crank when engine is hot... dunno if really is timming OR rotor or field on starter are starting to get damaged and when is hot, power is being affected.

Let's think is the starter motor... do you think could it be rotor or fields ?

[bordin34]

Could it be some clutch that isnt working somewhere coming off a belt from the engine that allows something to spin faster than it should?

[charger Downunder]

Check your earth,I even ran an extra earth from my engine to the body.

[Nacho-RT74]

I have double ground... the block one and the body ( radiator support core ) one

[Plumcrazy]

When the bushing in the head plate wears out, it allows the armature to rub the frame.

[Nacho-RT74]

I dissasembled recently the starter because clutch went bad, so probably it could be just the plate moved out from center making armature meets with frame and field assembly ? weird is just when is hot... metal expansion because heat ?

[Back N Black]

Maybe you need a heat sheild around the starter?

[Nacho-RT74]

that would it be weird, since I have made 8 hours travels without problem, and now with just start the engine and keeping by 10 minutes, already is hard to crank again. I have to wait around 5 minutes to start it AND hardly spins

[twilt]

I used to have a BB 73 that was hard to start when hot and would go thru starters about once very 6 months. Turned out that it was nothing but a timing issue. Once i set it properly, I had no further probles.I do not know the scientific explanation but incorrect timing can cause the problem that you describe.

[Nacho-RT74]

thats the first stuff did it came in to my mind, but actually I have tryed to start on dist several positions when it happens and nothing changed a lot. Of course makes it easier to spin retarding the timing up 0º , but still hardly spins. ( I have 0º and 10º marks between block and dist housing )

I started to get this problem without move anything

[Paul G]

Sounds like heat soak. The starter will slow down when it gets hot. How is the battery voltage? If the starter is heat soaking you will see a big drop in battery voltage when cranking. After cranking ends the battery voltage will come back to normal. That is a sign of starter heat soak. If the battery voltage does not come back to normal could be a bad battery. Also double check your battery conections just to make sure thay are good. Check the cable ends also to make sure thay are not going bad. One time I had a bad cable. It looked fine but was bad under the insulation. It got real hot during cranking. Thats how I found it was bad. 

[Nacho-RT74]

Sounds like heat soak. The starter will slow down when it gets hot. How is the battery voltage? If the starter is heat soaking you will see a big drop in battery voltage when cranking. After cranking ends the battery voltage will come back to normal.

that's EXACTLY what is happening...
what is soak ?
what I would need to replace ? fields ? armature/rotor ?

[Paul G]

When this happens I have always replaced the entire starter. I have never rebuilt a starter myself.

I have the smaller high torque starter on my Charger right now and I like it. If you are going to replace the starter I would consider a high torque mini starter. 

[Nacho-RT74]

the one I have is with bigger gear on armature what makes spins faster tha the ooooold ones. This one is same Mopar but I think lates 70s