Mini Starter won‘t crank when hot!

[Super-Bee-69]

I‘ve tried several Mini Starters after installing TTI Ceramic Coated Headers, but when engine is hot none of them will crank! Powermaster, original Mopar, all the same. Extra power cable, still the same.
What‘s the real issue with that?? Is it just thermal heat to the starter??

 

[BMosely]

What is your base timing? It sounds like you have too much advance. Symptoms are starter bind when hot especially if it fires right up cold. I am running 18* on a 440 and that was getting right up against the line for the starter.

 

[dvw]

A hot starter requires more voltage. A battery with 12.2 volts is only at 50% state of charge. Higher compression motors are tougher to crank. I fought the same issue on my racecar for years. Even when trying to crank with ignition off , then flipping it on. Finally replaced the two 12 volt batteries with a single 16 volt. Haven’t had an issue since.
Doug

 

[PurpleBeeper]

Yes, any starter will turn slower when it gets hot. I would suggest you look at wrapping the headers (at least near the starter) and wrapping the starter too with "heat wrap"

 

[Hey-O]

I've had the same problem in a non Mopar. Timing. IMO

 

[moes]

Check the ground cable to the battery for resistance.

 

[MoparLeo]

Get a cheap infrared/thermal heat gun and directly check the temps at the terminals, wiring as well as starter.
Heat is the biggest enemy of current. More heat requires more current. Wire gauge, connections, grounds. Clean and tight ? Battery have enough CCA ? Fully charged with a battery charger ? 12.6 or more after removing surface charge ?
If it is radiant heat, this has been an issue for many decades. Blankets, shields, wraps. Many solutions out there.

 

[Geoff 2]

Could also be engine internals tighten up with heat while sitting heat soaking. Piston to bore clearance etc.

 

[evilmopar]

I have the same issue, It just came out of the blue, When i try to crank it when hot at the gas station for example, it hardly turns over but if i keep cranking it it runs faster and faster then fires right up. I´ve tried a new battery, removed the main switch. Checked the starter relay, and the ground. The starter is about 110F after been sitting for a while when engine is hot. I can turn the engine with a spanner by hand. I run a ministarter, Fenderwell headers, 11.6:1 cr.

 

[Sixpactogo]

It is possible that the hot start issue is not the starter at all. Could be a dead cell in the battery. Try swapping in a different battery.

 

[evilmopar]

It is possible that the hot start issue is not the starter at all. Could be a dead cell in the battery. Try swapping in a different battery.

Don’t know how it went for the TS, but i have a brand new 105Ah, 950CCA Battery in the car but still have the same issiue.

 

[evilmopar]

Think i found the issiue yesterday.. The transmission was loose and there was a gap between engine and trans at the starterside. One bolt was missing, the one above the starter and everyone else was loose including the ground strap. Don´t know why it got loose and lost a bolt, i´m 100% sure everything was pulled tight because i mark the bolts i pull tight (old habit from work) and all the bolts had a marking. I hope the bearing and seal at the input shaft have survived... will do some testing today and see if it works

 

[Hubbarocks]

same issue as the others here like the starter cannot turn it over at first once it's up to temp.
After trying a lot of solutions, the problem has improved from not turning over at all, but not fixed.
440 / 9.8:1 compression. Dougs headers, MSD ignition

my battery is located in the trunk. i replaced the red top optima b/c i thought that was the issue. same situation.

i pulled the starter and took it to a reputable rebuild shop. they said yep, once it get hots the solenoid swells and gets locked up. they rebuilt and tested it. I asked about the heat sink issue, they said DO NOT get a shield / heat blanket around the starter. it just traps the heat in. they suggested to wrap the header. my local race shop said same thing. So i just wrapped the header.

Now , the first initail crank , it will act like it is stuck. i bump it another 2 ~ 3 x and the engine fires as soon as it gets a good spin.

i thought it might be a ground issue with my battery being in the trunk. i ran a 0g ground from the battery in the trunk to the inside the firewall and bolted it to the back of the ground at the firewall from the inside. The same bolt from the outside of the fire wall i use as a ground for everything on the passenger's engine bay and ground strap to the back of the head on that side. i have another ground on the engine in the front drivers head going down. There is .002 ohms between the block n battery (when hot) 100% engine is getting good ground.

BUT same issue ... scratching my head at this point. Looking for alternatives.

maybe try another (brand new) starter ?

 

[Hubbarocks]

Could also be engine internals tighten up with heat while sitting heat soaking. Piston to bore clearance etc.

maybe this could be an issue. doesnt sound like that would have a resolution....

 

[evilmopar]

Ichanged all my wires to a 0awg cable from the battery to the starter and up to the starter relay. Still had the issue, took the starter appart and it was very dirty and black on the cupper connectors, the commutator was also very black and had some oil on it, also only found that 3 of the brushes sprung out when i pulled the rotor out, the 4th i had to pry on to get it to spring out, but not sure how it was when the rotor was in the stator. The wires in the stator also looked abit dark and had a "funny" smell when i stuck my nose in it . I´ve ordered a new "Pro torque" (summits own brand) starter from summit racing and i will see if that´s the solution. i had this problem coming to me over night engine was new built last year and it have been working flawless for over a year.

 

[Hubbarocks]

kinda want to pull the starter out and realign it ... but if im going to pull it out. i may as well replace with a new one at same time.
i noticed when she's good and hot. it will NOT even try and turn over. i can hear the solenoid actuating but cannot turn the motor over. i have to sit for a while and let everything cool down.

it's getting to be a PITA.

 

[evilmopar]

kinda want to pull the starter out and realign it ... but if im going to pull it out. i may as well replace with a new one at same time.
i noticed when she's good and hot. it will NOT even try and turn over. i can hear the solenoid actuating but cannot turn the motor over. i have to sit for a while and let everything cool down.

it's getting to be a PITA.

I have the same problem except that min will turnover but very slowly, after it has been cooled down it works fine.. And in my setup it can´t be heatsoak to the starter since i run fenderwell headers and it has been working for over a year then all of a sudden. Got a new starter in the mail yesterday ( Summitracing Protorque part#SUM-820337) I´ll try it on today and then give some feedback. For now i´ll post pics of the old starter, 7 years of duty and came from a Chrysler Voyager V6.

The "missing" brush is just stuck, it sprung out when i poked it after i took the picture

Cleaned the contact but it´has been sitting in an angle

 

[evilmopar]

And BOOM! It’s fixed!! That summit starter was insane!! The engine spins so fast i’m almost in shock . 11,6cr and a heavy stroker bottom end was nothing. Didn’t think that it was that amount of difference from a stock Denso starter from newer Chrysler engine. It had the same exact dimensions. Soo happy!

 

[68 Sport Satellite]

And BOOM! It’s fixed!! That summit starter was insane!! The engine spins so fast i’m almost in shock . 11,6cr and a heavy stroker bottom end was nothing. Didn’t think that it was that amount of difference from a stock Denso starter from newer Chrysler engine. It had the same exact dimensions. Soo happy!

Can you run the motor to get it hot, shut it off and let it heat soak for 5 min, then try to start it up again and report back? If it handles that as well, that's great news.

I have had a mini-starter from Napa Auto spec'd for a '98 Dakota for a few years. Cold it works great. 90F summer heat fuel station pit stop, get in and crank it - the motor would struggle. I was running 4 AWG pos and neg battery cables. I've since switched to 1 AWG for both as well as upping my battery size from Group 24 (780 Cranking Amps) to Group 27 (985 Cranking Amps) and MAN WHAT A DIFFERENCE! Any heat soak issues have been overcome by the higher current.

 

[Kern Dog]

My 75 Power Wagon had the dreaded heat soak slow cranking issue. It rarely let me down but last week at the dump, I had to get a jump start after stepping out to pay at the booth.
It is embarrassing to ask for help like that. I had a used Powermaster starter that was in my red Charger. It was immediately evident why I pulled it out of the car. It cranks okay when the engine is cold but is as slow as Brandon when hot.
Today I swapped in a rebuilt 1995 Ram 1500 starter from the NAPA store. Cold, warm or up to temp, it spins fast.