VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 Hot strating problem

Having a hard time getting starter to turn over fast enough to start when engine is hot just put in a new 590 cca battery checked timing and that is ok it spins over great when cold i also put on new heavy cables and made sure all connections were clean is the starter going bad?
if so why does it work fine when cold but not when hot the starter it self does not seem to get hot, just luke warm to the touch any idea's?

Tims37,

Does it actually crank slower when it's hot or just not want to start? If the latter, it could be vapor lock. My 40 did that just last week. 'Course it was 95 in the shade here, but I know it also gets hot in MN in the summers too. Just a thought.

Doc

It just turns over alot slower barely enough to start good thing it does start pretty good but it does barely turn over makes me nervous that one of these times it will leave me stranded so any ideas why this happens i have really clean connections big heavy cables new 590cca battery
and i've felt the starter and it does not even feel hot is this just the way these old 6 volt systems are? or should it turn over just as fast hot as it does cold?

Heat effects 6v starters but should not effect them to the degree that you are discussing. A hot engine is a tighter engine and would offer some drag no present with a cold engine. My 52 used to do the same thing but the addition of an 01 size cable, clean contacts and a new woven ground strap seem to have cured my problem but from the sounds of it you may have a problem with the starter itself.

If all else has been done-overhaul the starter.Armature and fields should be checked-not just replace brushes.When all is as new they will turn over just as fast hot or cold.

Hi Tim,

Don't remember, has the engine been rebuilt recently? Your symptoms are in line with a rebuilt engine sporting new aluminum pistons. The aluminum expand more that cast iron pistons and mechanics are known to fail in leaving enough clearance for the hot aluminum pistons.

Perhaps with time, things will get better.

I had the exact same problem on my '51 Chevy for years. When hot, the engine would turn over very slow, and it would not start. After I tried everything else, I finally installed a 0000 copper welding cable for my positive lead and that cured the problem. As a matter of fact, we just got back from a car rally this afternoon with the '51 Chevy. It is 102 degrees this afternoon and when I arrived home I turned off the vehicle and let it sit for about 5 minutes. In doing so the temp. gauge went up off the scale past the "Hot" mark. I then tried to start the car and the engine turned over fast, and the car started right up........almost instantly. Previously, it would never start at all when hot until I installed the welding cable.

I would also expect that if in fact the starter was rebuilt properly and the engine has only a few hundred miles on a rebuild it is too small of cables, the ones sold by auto parts vendors are probably too small of a gauge, also the woven ground straps can have corrosion inside and look ok. also the switch can contribute to the problem by adding some more resistance to the circuit. Six volts need as low resistance between the starter and battery as possible, the cable length is a fixed dimension but you can change the gauge, ( I would not use anything smaller than a 00 copper, 0000 copper probably will have to come from a welding supply place. a good starter alternator shop can build cables that will work, make sure they use the large solder on battery terminals also, those bolt on replacement clamp-on terminals won't hack it on a six volt system very long till they get corrosion in the strands.

Thanks for the advice the engine was rebuilt about 10 years ago but not really any miles on it but the stock pistons were used and i put on a really heavy positive cable not sure what gauge but it's about twice the size of the 12 volt cables and i also put on a new woven ground strap so i think i will look at the starter and the switch..THANKS AGAIN :)

Tim,Drive it down to Wausau,Wis on Sat for our get-together.Will be a good run for it

Gene i would love to but have previous plans. I looked at the cable i used and it said 2/0 gauge
does that seem heavy enough? The cable looks very big..Thanks Tim

As mentioned above, the 0000 cable cured my problem. Previous to that I was using a 00 cable.

Do you know if 0000 is bigger that 2/0 gauge cable? This cable is about the size of my thumb
which seems pretty big to me

Tim,
I have the large cables from Farm & Fleet on my cars.Is that what you are using??I believe its was marked 2/0 or something - but has worked great for me.Its much larger than the original equipment cables.Looks to be almost the same size as the heater hose.

Yes that is what i have i got them at fleet farm
they seem to be pretty heavy cables. i also looked at the starter switch and the cooper contacts don't look to good either so i think i'll try that next then i'll look at the starter if that does not take care of it

I have some "extra" switches if you need one.

Yes i could use one email me and let me know how much...THANKS GENE

Yes, 0000 (or 4/0) is bigger than 00 (or 2/0).

I had cables made for my old cars at a tractor place. Two of my cars use 00 size and one is single 0. The man who made the cables said that single 0 is more than heavy enough but be sure the connectors are large enough also. On two of my cars I ran an extra cable from the ground connection to the starter itself. Always cleaning the connection areas until they were bright. I may be wrong but I think the original cables were 1's.