Posted By |
Discussion Topic:
8 volt battery
-- page:
1
2
3
|
|
41woodie |
06-23-2013 @ 3:03 PM
|
|
|
Member
Posts: 11
Joined: Jun 2011
|
Advised about 3 years ago to put an 8 volt battery in our 41 ford by an old mechanic to help starting. Car is used only around neighborhood and local shows. I know knowledgeable guys on forum don't recommend these batteries. I bought a 6 volt optima and car will not start. I have adapter on distributor that uses hotter coil. After cranking off and on with new battery, the negative cable was very hot. The oil pan has the grounding bracket installed and ground cable from positive to firewall looks ok. Thanks in advance for help.
|
oldford2 |
06-23-2013 @ 5:58 PM
|
|
|
Member
Posts: 275
Joined: Oct 2009
|
Not a good idea. Just a patch on problems you can fix. Do a "search" on Fordbarn.com "8 volts" for lots of good advice. John
|
40cpe |
06-23-2013 @ 6:05 PM
|
|
|
Member
Posts: 476
Joined: Jan 2010
|
The hot cable is telling you that there is too much resistance in the cable. It could be from corroded connections or terminals, resistance between the cable and the end connectors, or the cable wire is just too small, as in a cable designed for 12 volts. The cable should be designed for 6 volts, usually size "0" or "1-0" wire. You didn't mention a cable from the block to the firewall to complete the ground circuit. Installing the positive cable directly to the block reduces the chance of resistance in connections to the firewall and then to the block. All the cables need to be of proper size and all the connections clean to provide maximum cranking power.
|
ford38v8 |
06-23-2013 @ 6:21 PM
|
|
|
Senior
Posts: 2765
Joined: Oct 2009
|
Woodie, I have a couple of answers fore you, and a request, which comes first: Please follow up on the answers you get here. We like to help, but we also like to hear if our advice did you any good. OK, first, I'm glad you disregarded the old mechanic's advice to get an 8 volt battery. An 8 volt battery is only a band aid, not a fix. The Optima you did get is one of the best things you could have done, so good on ya! The "grounding bracket" on the oil pan can do that, but it's main function is to support the generator against twisting away from engaging the flywheel under load. Another must have item for that reason. The cable running hot sounds like the real culprit here. You may have a 12 volt cable, not big enough to carry the load. You need 00 AWG for a 6 volt system. !2 Volt cables are smaller gauge, I think maybe 2 AWG ? Not sure. Another reason cables get hot is the terminals themselves. A dirty or loose terminal will produce heat from the resistance, just as a small cable will have resistance. Clean the terminals to bright metal, and use dialectric grease in all connections during assembly to prevent oxidation, the devil of electrical resistance.
Alan
|
fla48 |
06-23-2013 @ 6:26 PM
|
|
|
New Member
Posts: 128
Joined: Nov 2011
|
Also make sure the attach points for the ground cables on the firewall and engine block are clean, not painted. I agree with 40cpe about the connections.
|
TomO |
06-24-2013 @ 8:30 AM
|
|
|
Senior
Posts: 7256
Joined: Oct 2009
|
The hot ground cable should be checked out, but I don't believe that it is your problem. Did the starter spin at a normal speed or did it struggle to turn the engine over? If the starter struggled to turn the engine over, check the voltage drop from the NEG terminal of the battery to the connection on the starter by connecting your voltmeter COM lead to the NEG battery terminal and the POS lead of the meter to the starter motor terminal. Crank the engine and read the voltage. It should not be more than .5Volts. If it is more than that, move the POS lead back one connection at a time and read the voltage the same way. Each connection should not read more than .1volt drop (that is : battery cable at battery to solenoid .1V, battery cable to starter cable on solenoid, .3V, etc.) The grounded side of the starter circuit should be checked out the same way by connecting the POS lead of the meter to the POS terminal of the battery and the NEG or COM lead of the meter to the starter case. The reading should be .1Volt or less. Higher readings could be caused by bad ground cable, bad connection at the fire wall on both the battery cable and the engine cable or a starter that has the oil pan mating surface painted. These tests will show you which components are not up to the job. You are using a modern coil, but did you check the spark? It should be at least 1/4" when cranking the engine. Most of the modern coils sold have an internal resistor and the resistor under the dash should be bypassed by hooking bot wires on the same terminal. Did you check for gas in the carburetor? Try spraying some starting fluid in the carburetor.
Tom
|
supereal |
06-24-2013 @ 8:52 AM
|
|
|
Senior
Posts: 6819
Joined: Oct 2009
|
As noted above, the bracket that secures the end of the starter (not generator, Alan) is to lessen torsion of the starter. Follow TomO's good advice regarding measuring the voltage drop of each component of the system. If all checks out, it is likely that the starter motor, itself, is the problem. Worn bushings permit the armature to drag on the pole shoes. In that event, repair or replacement is the cure, not an 8 volt battery.
|
Brendan |
06-24-2013 @ 4:26 PM
|
|
|
Member
Posts: 46
Joined: May 2011
|
Brake Ohm's Law go to jail... lol. the first thing is figure out why the cable is getting hot. I bet it is too small. and connections are dirty. with Ohm's Law, the lower the voltage the higher the current, and higher voltage lower current. its kind of like filling a swimming pool with a 1/2 in hose, or using a 2in hose. I hope thus helps Brendan
Can't spell my way out of a paper bag!
|
TomO |
06-25-2013 @ 7:42 AM
|
|
|
Senior
Posts: 7256
Joined: Oct 2009
|
The cable could be hot because the circuit is drawing too much current or because there was not enough time between the cranking of the engine to allow the cable to cool off. The above tests will show if the cable has excessive resistance or the problem is in the starter. The starter motor should draw between 150-200 amps, with most of them at the lower reading.The stock 6 volt cable is 2 AWG for 37-48 Fords. The earlier cars with the battery under the floor should probably use 1 AWG due to the longer length of the cables. The 2 AWG cable will drop about .1 volt for each 2 ft of cable at 6 volts when 200 amps of starter current runs through it. It will stay cool to the touch if the 15 second - 1 minute rule is observed. That is 15 second of cranking and 1 minute of cool off time. This rule was set to preserve the starter motor and prevent it from overheating. If this rule is ignored, the starter and the cable will get warm to the touch.
Tom
|
41woodie |
06-27-2013 @ 1:44 PM
|
|
|
Member
Posts: 11
Joined: Jun 2011
|
thanks top everyone who responded to my questions about 8 volt battery. I took my dremel and sanded down all the grounds and got a heavy duty cable from a tractor supply store. car turns over and starts great.i'm a novice at this so probably have more questions in the future. thanks again for helping me out.
|