VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Keeping a starter cool ?

Hey Guys,
Still having some difficulty getting a good crank when re-starting my engine when hot. When cooled off, no problem. She spins nicely.
A friend mentioned some older Chevys had an asbestos heat wrap around the starter to isolate it from a hot engine, thereby preventing or minimizing "heat lock". I'm thinking that might be worth trying. I've upgraded to 00 cables, starter has been twice checked out and is okay. I've read some muscle cars had heat deflectors on their starters when located next to the headers. My car's a '32.
Thanks

Here's an example
http://www.opieoils.co.uk/p-84442-hp-starter-shield-medium-size-starters-7-x-21.aspx

Check the ground path from battery to starter. All connections need to be clean and corrosion free. A little oil or grease is okay as long as the parts fit tight. Can't have paint or corrosion. An alternative is to run a ground directly to the starter case. Positive connections should also be checked but are not as often the problem as the negative. Also do a check on battery condition. Some don't produce the output they should.

All good and shiny with the connections, the battery was load tested and even exceeded the rated CCA.

While the wiring connections may be shiny, keep in mind that the ground path depends on where the negative cable is attached. Often parts that have been painted prior to assembly end up with paint insulating parts that are not meant to be insulated.

Steve that is a very good comment. hardaground could try grounding the Neg. lead of the battery to the starter mount bolt or just run a second ground from where the Neg. is grounded now to the starter mount bolt and see if that helps.

Thanks Steve,

My new 00 ground cable attaches to one of bolts of the U-Joint/free-wheeling assembly,. I first sanded it first to remove all paint. The cable was alway there I believe.
She cranks good except within 20-30 min or so just after a shut down. My temp gauge reads between Cool and Normal. I assume it's accurate…..

BTW, I'm taking the 'ole girl up to the antique car exposition at Sturbridge Village tomorrow. Supposed to be 100 pre-1946 cars there. No silly muscle cars or ear piercing Beach Boy music playing. C'mon down ! Help, help me, Rhonda

My ground cable is located in the same manner. If your good with a multimeter then that's probably the best way to check. You will want to check the path from the end of the cable back to the starter mounting on the flywheel housing. There are ways the path could be interrupted-paint on the starter or flywheel housing or sealer on the bolt holding the cover/cable. It also could be the armature windings on the starter . Thanks for the info on Sturbridge though I doubt I can make it. Andys29 has some good tips that may help.

What is the CCA of your battery?

Also, for more power on starting you can go with high torque field coils in the starter.

640 A at 0 degrees F. It's a fairly new NAPA 6 volt, not cheap either.

Andy, I'll try that 2nd ground or re-direct the existing ground to the starter hold-down bolt. I previously sanded clean the mating surfaces of the starter to engine housing. No paint left, super clean. Ditto on the bolt attaching the neg cable to the U-joint/tranny assembly.

Should I assume by these responses that a starter already warmed by a hot engine on a hot day is NOT a possibility ? Could the added heat generated during normal cranking compromise its power somehow ? She does turn over fine when cold.

You need to be able to check the amp draw when starting to see if the problem is in the starter. The rebuilder that did my starter had the fields rewound as he explained to me that the copper gets "punky" after a lot of years. You won't know until you can have someone check the amp draw while trying to start. I would check it both cold and hot.

If it is a bad, questionable, wire, connection, the best way to find it is by doing a voltage drop. First go from the negative on the battery to the starter case. Set your meter to volts. Crank the engine and read the meter. I am not sure of the voltage drop that is allowed on a 6 volt system but I would think it would be less than 1.5 volts. Then do the same with the positive side. Connect to the battery and the positive on the starter. Crank the engine and read the voltage on the meter.
Voltage drop is the easiest way to find a problem and not just shooting in the dark.
If you would like more information PM me and I will talk you though it over the phone.
Craig

Sounds like the best diagnostic approach, checking the amp draw. Meanwhile, I'll park on hills. Surprisingly, there always seems to be 2 guys around to give me a push if needed, especially at gas stations...

Also, have you checked the condition of the copper contacts inside your positive battery/starter button assembly on top of the starter? Sometimes, they've corroded or are worn and really are not making solid contact.

My '68 Chevelle suffers from overly hot starter condition so I've installed an asbestos wrap on it. The problem there is the solenoid getting too hot, not the starter itself.

My'31 has never had an overheating starter problem like you are describing and it gets awful hot here in Texas on July 4th.

Happy Motoring!

Thanks Knapp, Here's my starter contacts.
The two surfaces don't line up perfectly but maybe they aren't supposed to. But maybe there's wear and they can't mate up against each other tight enough to properly transfer the voltage? Like you said, not making solid contact. Interesting condition and fix on your Chevelle. I may wrap mine if the other suggestions here don't help. Can't hurt.

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I don't think the problem is in the switch. It's mechanically operated so should be the same whether hot or cold. With the multimeter readings you will get a better idea of what is happening. I think the problem is inside the starter and not the heat from the outside.

Try the high torque field coils............

Could be an earthed armature and or field coils,shorted fields or armature or the armature is "poling" ie;rubbing against the pole shoes due to worn bushes.

I'm sure the high torque field coils would be an improvement, but I think he first needs to diagnose and identify the cause before replacing any parts.

If this is the case and the starter has been checked out twice by a qualified shop and nothing wrong was found, then it would be a good idea to install high torque field coils to see if that cures the issue. Besides, the high torque field coils would definitely be an improvement even if the starter is working fine.

We'll, I'm getting there. The local shop tested the entire starting circuit. They said all is in order, loaded tested fine, started fine hot or cold. Prior to bringing her in, I retarded the timing a bit more and it seemed to help. The mechanic, who has much 6v and antique car experience thought that might have been my problem all along. I originally followed the advice here and advanced it to 18 degrees. She was hard to crank, even pulling the knob out and she still knocked some on the hills. Now I adjusted the dist back to between 12 and 18, I pull the knob all the way out when starting, and ease in until the power seems right when on the highway.
Any of this make sense ? Still learning…..I have nothing to compare this to and no one to bounce things off of, but you guys.

Ugh......Double Ugh
My 32 Chev coupe is having the same hot crank problem. New battery, rebuilt starter, new cables. No installation issues I can find. No load voltage is 6.3, voltage drops to 5.4 when cranking. Pressing the starter pedal when cold the engine cranks at about 90rpm. Hot cranking the starter will turn the engine over about 180 degrees then - nothing. Hit the pedal again and get another 180 degrees.

There are thrust washers at the end of the starter armature. I believe the washers take the axel load of the starter when canking AND control the end play clearance. Could it be there isn't enough clearance when hot?? And this would bind the starter?
Anybody know how much end clearance there should be?
Bye for now
Mike

There should be about 1/16" to 3/32" end clearance.

Try retarding the spark by pulling on the spark knob when hot. It might make a difference.

Good Day Everyone
Yep...Setting the correct spark fixed my hot start problem.
Id like to thank everyone on this chat site. Ive had numerous problems over the past 8 years of my 32 chev restoration. Now that I'm getting close to the end and my 32 coupe is running fine, I would like to thank everyone on this site that has helped me over the years. My Chev is a much better car from belonging to the VCCA.
Thank you all
Bye for now
Mike

Just curious, what did you finally set the advance at ?

Wow, 8 years of advice !! I'm at a mere 8 months on this site. From my first post its been an enormous help.