1971Ultra

I just installed a brand new GM Hi torque mini starter on my SBC. I have no issue starting the car in the morning.

Where I do have an issue is getting the car started after it has run for awhile. I always attributed it to heat and after reading some other threads I believe the starter suffers from what is known as "heat soak".

Other than replacing the starter is there a remedy for this phenomenon?

Gordonm

Is this happening with the new starter. I used to have heat soak with my old style starter but since going to the new GM mini starter no matter how hot it is it starts right up. You might want to make sure your wiring is good. Most important is the ground wires and make sure they have a good ground.

bobs77vet

have you checked your battery later? and specifically measured the specific gravity of the cells? you may have a weak battery. most hi torque mini starters do not have heat soak problems even with the headers right next to them like on mine.

Stewart's74

I agree with Bob.
I also had the same issues. I switched to a mini starter, heat shield, etc....STILL had problems.
I switched to an Optima Red Top battery and the problem went away. HOWEVER, one day I was under the car and noticed that the neg batt cable that attached to the frame was badly corroded. I then replaced that as well.
In hindsight, I'd bet my problem was the bad ground on the frame. Check yours...

stingr69

Several ways to fix it. Some say mini-starter and some would say the wiring has too much resistance or the solenoid spring is too stiff but I would say to add a Ford Starter Relay. It costs peanuts (about 10 bucks) and some wire/terminals. This is the fix from the old school and it is effective.

Move the original thinner purple signal wire from the GM stater solenoid over to trigger the Ford relay"S" terminal, make a 12 ga copper stranded wire and attach to the fat terminal on the starter (where the battery positive cable is still attached) to one of the two fat terminals on the Ford relay, make another 12 ga wire to the other fat terminal on the Ford relay to where the original GM thin purple signal wire used to be hooked up and that is it. Make sure the new relay is grounded to metal.

This method is a little different from the way Ford uses it. The main power for the starter does not flow through the Ford relay in this particular setup so the relay is way over-sized for this application. This method does not require any new battery cables either so that is a plus.

All this assumes you do not have any corroded connections or a bad battery. People had this problem on Chevys even when they were still fairly new once they started to modify them adding headers etc.

-Mark.

1971Ultra

The starter is brand new and the battery is fairly new. And yes I am running headers on the car. I will start with the wiring and go from there.

As always this forum ROCKS!

Thanks to all.

K

Bee Jay

My Corvette had hot soak problems since it was new. Chevy actually had a warranty bulletin on it, which called for replacing the solenoid spring with a "lighter duty" one. The "heavy duty” springs was getting so hot that it would bind inside the solenoid, and not kick the starter gear out to the flywheel. I have since replaced the very large and heavy starter that would be nestled in between the header pipes, with a gear reduction starter. I was so impressed with the results, that I did it to my Porsche too. I haven't had a problem since. But I did do the relay mod on the Porsche. The starter now gets 12 volts directly from the battery, not from the ignition key harness.
What is your compression ratio and initial timing? That gave me a problem once too. Do you get a click or just slow cranking?
Bee Jay

1971Ultra

Ratio is 9.6:1 to 1 not sure on the timing. I just get a click. It would start after about 10 to 12 clicks.

carhound

You may have the timing a little too high. That will make it act like that.

cardo0

Well my mini didn't line up so i installed a heat shield over my stock starter. Worked with headers in 110*F stop and go for me. U can see my $25 JC Whitney shield in my profile link. I also use the stock starter bracing that Bubba hates and removes. Hey, this ain't summer time! I suspect u got other problems.
BTW this a popular problem and a search should provide plenty'a info.
I won't get into the old hearsay to add another solenoid in series with the existing solenoid that's still hot (higher coil resistance) and has to do the real work of throwing out the bendix gear and make up the contactor plate. Sorry stingr69, not wanting to flame u but this is just bad science and if it works its only by coincidence that it corrected something else like a week connection. :o

Oh well its time to had for cover. I can sense some incoming rounds now! cardo0

stingr69

No problem at all, Cardo.

This is a band-aid solution just like the other solutions for the problem. If your starter will crank by jumping the terminals using a screwdriver, the Ford solenoid trick will work. It takes the place of the screwdriver, thats all. People have been using the screwdriver to short out the terminals on the starter when it gets hot for years. Why? Because it works. The new relay is in series but not with the GM solenoid anymore. The demands on the Ford relay are lower than the demands of the GM solenoid. The relay is used to bypass the existing high resistance circuit so the solenoid can do its job without the rest of the resistances in the original circuit.

The problem comes from too much electrical resistance in the circuit (what ever the cause - heat, age, twisted black tape connections, corrosion, etc). The resistance causes a voltage drop in the signal line to the GM solenoid. The GM solenoid tends to not be able to pull-in the bendix and complete the circuit on anything less than full battery voltage (at the terminal) especialy once it gets hot. Anyone here NOT had this problem before? I know I used to.

Here is the reason this trick works - The Ford relay will pull-in and make contact at much less than full battery voltage where the GM solenoid will not. The Ford relay is able to send full battery voltage directly to the GM solenoid on the starter without having to deal with the voltage drops in the rest of the wiring harness (same as jumping the terminals using a screwdriver). Then the CAR CRANKS! Again, this is a bad-aid just like the other solutions BUT it does get the job done.

No flame, just debate and that is how I hope we keep doing things around here. The discussions help everyone.

-Mark.

fauxrs2

I'm with stingray on this one...The remote solenoid works...I've used it on two different cars when I didnt have the $$ for big fat sexah gear reduction starters

Is it a bandaid.. you bet...but it works every time regardless of how hot the starter gets...it works because the bendix gets a full 12 volt shot.

I've seen cars with brand new wiring harnesses and brand new starters have the hot start problem...(come to think of it those brand new starters were from a local parts store so call that newly reconditioned)..this occured on a buddy's 70 camaro...1 remote solenoid later and he was down the road.. and still is to this day.

cardo0

Sorry stingr69, but shorting out the terminals only shorts out the starter switch. If shorting the starter switch makes the starter move roundy - roundy and turn the engine then the switch was bad or the solenoid has had time to cool.
Now u can short out the solenoid also to make the DC mtr turn - but the solenoid will not move to throw out the Bendix gear and the engine will not turn over.

Nothing u should be defensive about as most owners try to reason this without a drawing - current path picture. Once u draw it out u will see the GM starter mounted soleniod still has to kick out that Bendix gear. Adding solenoids in series only adds more contact resistance/voltage drop.
Again the solenoid on a GM starter has to throw out the bendix gear and make up the contactor to send DC power to the starter motor. If u cannot see this then i can't help u and have to stop here.

The Ford solenoid is a different animal and uses the DC starter mtr electric field magnets to create the magnetic force to draw in a lever that kicks out the Ford starter gear on the other end. While the GM uses a slug inside the starter mounted solenoid to do this job.

Good night. cardo0

stingr69

Here is a diagram in case anyone needs it.



-Mark.

strokervette

I don't think it is an electrical problem at all. I just went through all of this with mine. It took two weeks of troubleshooting and replacing parts with no solution. All I did to fix it was to install a shim between the starter and the block with a .020 shim. I couldn't believe how simple the solution was. Just check it out and try it.
Pry out the starter gear with a screwdriver to get it to mate up with the flywheel gear and you should be able to stick the tip of a normal sized paperclip between the tip of the starter gear and the base of the flywheel gear WHILE THE CAR IS AT OPERATING TEMP. Wear protective gear though because it is hot under there. Or just shim it little by little until it starts hot. I got lucky with one shim placed on the oil pan side of the starter. I made my own shim out of a peice of aluminum sheet metal. Just cut it with a pair of scissors to look like a washer. Use a feeler gauge to measure it. Good luck.

cardo0

Thats a great pix stngr69 and shows the original ign sw wires but now connected to the remote solenoid. So u still have wires going to that area on top of starter that may add or reduce resistance of thier own somewhat. And the remote solenoid eleminates the starter sw contact & wire resistance but will add its own contact resistance/voltage drop.

But the problem of heat-soak is in the winding resistance of the starter mounted solenoid. And the starter mounted solenoid is still there, has to make up the DC mtr contacter and throw out the Bendix gear. This solenoid is still hot and unprotected without a heat shield. Chevy knew this and installed a small heat shield that covered mostly the solenoid only. But the stock shield doesn't even fit with most headers and does'nt cover from the extra area of hdr tubes either.

Now 1971Ultra's mini doesn't have or use that solenoid to coil wire - though it could still help a weak stock ignition during mtr start. The reduction starters is soo much more efficient using much less current for the same starter gear speed. Also due to small size has much greater air space from hot exh piping for insulation - so i suspect other problems for a mini like bad connections and/or grounding.

The only thing i would add to ur diagram is an illustration of the starter solenoid winding, slug, lever and Bendix gear. Anyways, that's such a nice diagram i wish it was posted here on the forum for all to reference - but without that remote solenoid of course.

cardo0

stingr69

I added heat shields to my cars in the past but it was not always enough. The heat soak is the problem. The hotter the GM solenoid gets, the more voltage is required to sucessfully pull in the plunger. If you have numerous voltage drops in the system from the ignition switch, the neutral safety switch, the bulkhead connection, the old wiring harness with twisted connections, etc, etc, you can see why you could have less than the full 12V at the end of the line left over to pull the plunger in.

This is not something I invented. It has been done with success MANY times before by other people too.

-Mark.

cardo0

Well anytime u reduce resistance u reduce voltage drop and an improvement. Another trick that i learned from an electrician BTW is the starter mtr brgs are only bushings and usually poorly lubricated - so he would dissemble a replacement starter and hi-temp grease the shaft brgs before install.

BTW i covered all my new starter wiring with fiberglass sleeving as the old wiring was toast - this sleeving is cheap from JC Whitney too. This might releave ur wiring temp concerns stngr69. I had to cover my batt cable with heat shrink anyways (all cracked and possible path to short to gnd) and thought y not do it all right in 1 job.

I should add my heat shield has a complete air gap between starter and shield and only touches at 1 mounting screw on each end to reduce heat transfer - on the mtr not the solenoid. This took some more time but metal to metal contact with the shield can be worse than not using a shield. Also had to modify 1 end to clear hdrs but just 3 small cuts with a hacksaw and bend with and adjustble wrench.
I quess what i'm saying is that u can install a heatshield and still transfer plenty of heat to the solenoid - i don't like those wraps at all as once they get up to temp they hold the heat in the starter.

Again thx for ur honesty,
cardo0

johnt365

i went with a kit from Mad electrical. its basically the ford solenoid...
took the original battery cable to starter and moved it straight up. all the wires are on top away from the heat of the headers (in theory) then bought a thick cable to run down to the starter.

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