For the past half dozen newsletters we
have been discussing the Model T electrical system and how to get the best
out of our coils, magnetos, sparkplugs and the accessory distributors. That
about finishes the electrical system but before we leave the topic let's
take a brief look at using a 12 volt battery instead of a 6 volt one.
The T was originally intended to run
without the need of any battery and the fact that you could do so was
advertised as a plus. In the early years, most folks did connect a set of
dry cell batteries for easier starting though. When used only for powering
the coils while starting the T, the dry cells would usually last an entire
driving season.
In 1919 the closed Fords came out with a
6 volt storage battery, generator and starter as standard equipment. The
open cars were still magneto only. Then Ford added the battery system to
open cars for an additional $75.00. The starter was very well made and
really overbuilt for 6 volts. This certainly makes the 6 to 12 volt
conversion more practical! The generator was another story. It was
marginally designed at best and gave problems even when the T was the main
transportation on the road. But... marginal or not, it can charge a 12 volt
battery just as well as it can charge a 6 volt battery as long as the
charging rate is cut in half.
There are certainly advantages in
converting the T to the modern 12 volt system. A 6 volt system will not run
the coils well at speeds about 20 or 25 miles an hour! A 12 volt battery
will make the coils work at pretty much any speed. A real plus if you have
a poor magneto. A 12 volt battery will give you QUICK starts! If you don't
believe that, listen to any 12 volt T when the driver cranks it up! This
brings up an important point. Your starter and Bendix MUST be in good shape
or 12 volts will cause you to wish they had been! Timing should also be
correct. You do not want the engine to kick back when the starter is
spinning at 12 volts! A broken bendix or bent starter shaft are very
likely!
The Model T generator is pretty dumb. It
doesn't know 12 volts from 6 volts and will happily put out 10 or 12 amps to
a 12 volt battery just as it will a 6 volt one... for a very short time!
It will then self destruct with hot solder flying everywhere. If running 12
volts, you should set the charge rate at not more than 6 amps and probably 5
would make your generator happier. You will need to change the cutout from
a 6 volt one to a 12 volt one.
I'd suggest considering one of the 12
volt alternators that all the Model T suppliers offer. They not only offer
higher output but they automatically adjust the charging rate based on the
battery's charge. This is a real plus. The higher output lets you put
brighter bulbs in the headlights and the automatic charging gives you much
longer battery life and longer periods between adding water.
The only other change needed is to
replace the 6 volt light bulbs with 12 volt ones.
By the way... The Model T battery should
be installed with the negative terminal attached to the frame and the
positive terminal attached to the starter cable. Because the Model A
reversed these connections, you will sometimes find Model T's with the
connections reversed.
So... what does all this work give us?
You will have a T that will start faster and, I believe, will run better
on coils or distributor with lights that make it possible to actually see
where you are going after dark! I've got a set of 55 watt halogen bulbs in
my 12 that you have to see to believe!
I'd like to hear from you if you have any
questions or comments concerning anything we've covered in past issues.
Whether you agree or disagree, just write, call or email. My number and
address is on the front cover.
