850 battery cables

What size battery cables were original on the 6v 800 series? The reason I ask is that I rebuilt the engine on a 6v tractor this winter and it really made it grunt to turn over so I replaced the # 4 cables that were on it with # 1' It made a world of difference. So I checked my 850 which looks to have # 4 or so. I would like to keep the 6 V system but it could use a boost in starter power. Thanks to all to respond to these questions!

I changed my cables to #1 or #0 size cables, it made a difference in the starting electrical current to the old starter.

Probably should have the 56 year old starter rebuilt, but it still works.

The ground wire should be attached to the frame as close to the starter as possible.

AWG 4 battery cables are inadequate for vintage Ford tractors with 6V systems.

Copper is kind of like money and HP. Some's good and more's better.

AWG 0 or larger will suffice.

Dean

You want AWG 0 or larger. You want to remove the starter and clean all rust and paint so the starter is grounded good to the block. A new starter solenoid will help.

OTR truck repair facilities carries 0 and 00 wire and can custom make your wires at a reasonable price. 6v starting systems need wiring that has twice the area (3.14 x half the diameter squared) that 12v systems do as they have half the voltage and watts is watts and watts "is" what rolls the starter.....volts x amps.

You need 10v at the starter at 200 amps to roll a reasonable sized diesel on a 12v system. On a 6v system that's 5 volts so the amperage has to double to 400. Using ohms law, Voltage lost in the interconnect = resistance of the wire including terminations x amperage flowing through the interconnect circuit. Since you only have one volt to drop at 400 amps that is only allowing .0025 ohms of resistance in the interconnection. That's not very much, almost unmeasurable without costly equipment.

So use big wire, and bright and shiny joints (inside where the current flows, not necessarily on the outside where you look) that are "gootentite" is what it takes, and as one of the other guys said, don't forget cleaning up the case of the starter to engine block interface, and the bolts holding the starter to the block.

What I did on one hard starting tractor was to run a dedicated ground from the battery low side to one of the bolts holding the starter in place with the wire up against the starter case, rather than relying on current through the block and all, cleaning the surfaces where the lug mounts to the starter case under a mounting bolt, real good, using the same size wire as the hot lead. I "guarontee ya" that starter nearly jumped out of it's case rolling that 400 cu in Diesel on a cold day.

Just like you said, get the interconnect right and she'll fly assuming of course that you have a fully charged battery that isn's sulphated up.

Mark