Greetings, I recently brought a 1953 Chevrolet 5 window back from the dead (was parked in an old Oklahoma barn for at least the last 25 years). I've put a bunch of work into the truck and the truck starts and runs great now...except after I drive it around town for 5-10 mins and park and shut it off, it will not start under its own power right away. It moans and groans & never gets going fast enough to kick over. If you wait a few hours it will fire right up. I know the old 6 volt system can be slow to start, but what would be the reason it starts so good on the first start of the day, then struggles to start after it's driven around a few minutes? I have new battery cables and new 6v battery. The starter has been replaced sometime in the past (see pic). The engine is a 1954 model 235 that was implanted into the 1953 pickup by previous owner. Any suggestions are much appreciated. Signed, "The guy push starting that old truck in the wal mart parking lot..."
How thick are the battery cables? If they are designed for 12v cars, then they are probably too thin to carry the current that a 6v system uses (it takes twice as much current at half the voltage, to transmit the same amount of power)
I'll double check the cables in the morning. Read that guys get some from napa that have solved some problems in the past.
First make sure ALL the connections are clean and tight....positive, negative, ground, starter housing itself to the bellhousing, etc.
As Jim said, your cables need to carry double the current compared to a 12 V system. This is a 2/0 cable from the battery to the starter and I ran a double braided cable from the battery to the frame and another braided cable from the frame to the bellhousing. At 9:1 compression it still starts hot just fine. Also, I see you are running a direct coil contact sir from your starter switch presumably to your coil. This is normally done to bypass a ballast resistor. Get rid of the resistor on a 6V system and make sure your coil resistance is 1.5 Ohms or less. I ran a 0.6 ohm coil with a pertronix on 6V and that made a world of difference with hot starts on a high compression 270 inline six.
I see a bunch of stuff going on in your first two pictures. First like it's already been said, clean the contact points for the ground cable from the engine to the frame, from the battery to the frame, and put fatter battery cable on it. But you really need to make sure all the connections are clean, I can't stress that enough. I run a 6 volt Optima battery in my 6 volt car and that made a world of difference.
Check the solenoid contacts, if burned or pitted, could cause this problem. Sent from my SAMSUNG-SM-G930A using The H.A.M.B. mobile app
Surprised it starts at all, even invisible corrosion on grounds and connections is enough to seriously hork starting (and charging) current. Once you can see the rust and corrosion it will eventually fail. Those look like 12 volt cables, need to use 00 gauge cables for 6 volt systems. Grind down to bright shiny metal on the main ground points and connecting points at block frame and firewall and tighten securely. Sent from my iPhone using H.A.M.B.
Thanks for all of the input. I plan on checking and cleaning all contact points this morning and upgrading battery cables to the 2-00. Here's a pic of what cables are on the truck right now. I'm not expert, but they look like 12v cables. Thanks again for all the help!
Can someone explain why a cold start works fine as stated above but a hot start is more difficult with incorrect battery cables? Is it due to heat and expansion? A hot engine starts harder than a cold one? Not being a smart ass would like to know.
Zac, Here's one from left field. Make sure generator polarity and battery ground are consistent. Parents had a tractor many years ago that would start fine every morning and function perfectly until shut down for lunch. After lunch, starter would barely turn engine over, resulting in a no start. After several hours of resting, the tractor would crank normally and start. After a great deal of searching, problem was finally found. Recently replaced battery was installed with negative ground. Tractor was positive ground. During operation, the generator would discharge the battery and result in a no start when hot. (Hot actually had nothing to do with it. It was a time issue.) The 6 volt battery was able to recover enough energy over a few hours of resting to crank the tractor again. Correcting battery ground polarity solved the problem. So I suggest you either polarize the generator or verify correct battery polarity. Good luck, Danny
All of the above and, if the problem persists, try a new / different coil. I've had a couple in the past that would break down in the hot engine compartment. Leave the vehicle sit for 15-20 minutes and it started right up. Especially sensitive on 6v systems.
Several temperature related things can combine to make things more difficult for the starter. Compression generally improves on a warm engine compared to a cold engine making the engine harder to turn over. With a heat soaked starter - the field and armature winding resistance goes up - making current (and magnetic field strength used to spin the rotor) go down for a fixed battery voltage. Both of these can combine for a slow cranking motor and high pull on the battery causing lower battery voltage which also contributes to a weak spark . . . everything is going against you and at 6V, you can get voltage drop of 1 - 2 volts (up to 1/3rd your voltage potential) . . . comparted to a 12V where 1-2 volts is far less of a percentage drop in potential.
When you replace that battery, buy one from a TRUCK battery supplier. The Walmart/Pep Boys batteries have tiny, short plates and no capacity. Truck batteries are still full of plates & acid .... And your starter looks suspicious. The blue paint & 12v switch would make me want to tear it apart to see what else I could find.
I swapped out the ground cable with the new 2-00 and cleaned up some contact points and it's firing much better than it did. My winter project is to go through the wiring and redo most of it and clean it up. I'll plan on a new 6v battery soon as well. I also think the blue starter looks out of place so I'll probably replace it sometime in the near future. Thanks for all the suggestions!
Hell that battery is 10 yrs old according to the date code. I'd bet it hasn't been tested. Time for a new one.
I had a 56 that did the same thing and finally figured out the bronze bearings were bad and when it got warm it allowed the starter armature suck over to the side and drag. could start it every time when cold, drive it a while, shut it off and wouldn't start for an hour or so.
You'll notice the clip on the frame that the positive cable goes through- now look at Motion Guru's. That clip is filled with cable. Make yours look like his, to go along with the new ground strap. The positive cable you need isn't that long thankfully, since the battery is under the floor right behind the starter. As stated, a battery from the current decade will help too. I've gone through these same things on my '51 (gmc) and really like the optima batteries. Several of those skinny optima 6 volt batteries used in my cars.
I've been driving the truck around the past couple days and it's been firing much better since just cleaning the terminals and adding the new 2-00 ground cable to a freshly cleaned spot on the frame. I plan to pick up a new 6v battery here in the next week or so.
Not trying to beat up on you, trying to help you. In those pics can see problems. Yeah so maybe it's not a concours restoration, but notice all the crud and skunge on the battery top? This will tend to draw a battery down. Keep battery clean. Windex works good for this, it helps neutralize the acid. It also looks like there's no hold down, and battery is more or less loose in the tray. Battery shouldn't be able to move or bounce, they can get plate damage this way.
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