I am wondering what the typical amperage draw of the Model T starter motor is. Any informed values from our electrical experts?
Thanks in advance for your help.
Best regards,
Jonathan Bodine
Jonathan
Unfortunately I don't have data just a WAG. I am guessing that with only 22 HP and low compression at that, starter motor current shouldn't exceed 100 Amps or so.Hopefully someone has some measurements.
There is a type of DC ammeter that fits around the heavy starter wire. They used to be cheap.
Good luck
schuh
Maybe this will help,
http://www.mtfca.com/encyclo/Starter.pdf
Don't use current readings much. Voltage typically.
If you mean cranking the motor perhaps 150A+ at 5V.
If the battery breaks down below 4.75v that is not a good thing..
A hot motor will of course draw more than a cold motor.
Note in the PDF link the author has over 200A. Seems a bit high to me (225A).
I would expect 200amps in a starter circuit on a T. Rmembering that it's a fairly long stroke & big displacement (nearly 3 litres) The clutch will always offer some drag and most of all we're using a SIX volt system so for the same amount of work you need TWICE the current of a 12 volt setup.
That article is excellent;)
Cheers
A
Thanks for the opinions and info. I'm sizing the battery cables. As you all know cable size is dependent on current to be carried. Better to overestimate current and have cable too large than the other way around and risk an electrical fire.
Thanks again for the help.
Best regards,
Jonathan Bodine
Jonathan,
If you have time, look at the entry by Ron Patterson on April 20th in this thread...
http://www.mtfca.com/discus/messages/257047/283501.html
for a possible answer to your query.
Good Luck,
Dave
Jonathan
Assuming the starting motor is operating properly on 6 volts it should draw 70 amps free running, 150-160 Amps cranking engine and 450 Amps stalled pushing 12 pounds of torque.
Model T battery cables should be 1/0 with soldered (not crimped) wire terminals.
Ron the Coilman