Starter AMPS

[41LjH]

Anybody know how many amps an 8BA started draws ?

[Barlea]

725 amps at maximum torque. ..B.

[bbrocksr]

Originally Posted by 41LjH

Anybody know how many amps an 8BA started draws ?

Two -three hundred amps when cranking with a fully charged battery and a good working starter. If it draws more the starter is dragging or the engine is to tight or starting to seize.
Maximum torque is when the engine or starter is locked up and can't turn and is drawing maximum amps.
Bill

[Kurt in NJ]

In my notes ---normal cranking speed-100 rpm, with current draw of 225 amps at 4.75 volts ---lock load stalled --500 amps at 3.2 volts
Another note has -battery should crank the engine at 100 rpm, 190-250 amps @4.75 volts

if your voltage supply is lower it will take more amps to try and do the same work

I don't have specs for V8 starter free spinning on the bench, for "A" i have 2700 rpm, 50 amps, at 6v, the other "A" specs are about the same as v8 so this would probably work

[V8COOPMAN]

Originally Posted by bbrocksr

Maximum torque is when the engine or starter is locked up and can't turn and is drawing maximum amps.
Bill

.......technically designated as LRA, or "Locked Rotor Amps". DD

[jdl]

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The 49-51 Ford Shop Manual shows.. cranking speed 100.. Amp 550..
max torque 14 Ft Lb.

no load amperage...45-60

[CA Victoria]

I'm replaced my wiring and now trying to size my battery cables. I'm unning a 6v starter on 12v. How do I calculate the cranking amperage or is it the same as the numbers given?

[Capt Kirk]

I had electrical engineering back in my university days (I hated it!). I couldn't forget that stuff fast enough! My gut is saying "twice the voltage...half the amperage" but please don't take my word for it.

[V8COOPMAN]

Originally Posted by CA Victoria

I'm replaced my wiring and now trying to size my battery cables. I'm unning a 6v starter on 12v. How do I calculate the cranking amperage or is it the same as the numbers given?

Forget the calculations and use heavy, multi-stranded welding cable (available at your local welding dealer) with the ends made-up and you'll be "golden".........it don't get any better! Make sure starter has good clean ground contact where it bolts to pan. DD

[Capt Kirk]

Yes, I agree with V8Coop. I do remember that the more strands a wire has the better its current carrying capacity than a like sized wire with fewer strands. Welding cable has lots of fine wires and can carry a ton of current.

[CA Victoria]

Welding cable as with battery cable is made in some rather large sizes. It doesn't make sense to buy the biggest just because I do not know how to calculate the problem. While it doesn't need to be 100% I would like it in the ball park.
Maybe I have a little nerdy blood in me???
I found a formula to use but I need the starter cranking amps.

Thanks guys,

[Jack E/NJ]

CAV>>>Maybe I have a little nerdy blood in me??? I found a formula to use but I need the starter cranking amps.>>>

Nerdy? Yes, seems you are. So OK. Guesstimate a 1000 amps. Plug that into your formula. Then buy a work cable for a 250-amp Miller welder. That'll do just fine for your starter duty cycle. 8^)

Jack E/NJ

[bbrocksr]

Originally Posted by CA Victoria

Welding cable as with battery cable is made in some rather large sizes. It doesn't make sense to buy the biggest just because I do not know how to calculate the problem. While it doesn't need to be 100% I would like it in the ball park.
Maybe I have a little nerdy blood in me???
I found a formula to use but I need the starter cranking amps.

Thanks guys,

posts 3 and 4.

Bill

[CA Victoria]

Thanks yall'
Just in case anyone down the road reads this #2 awg cable will do the job in the F1s stock configuration.