Customer want to keep the car 12 volt but using a 6 volt starter has beat the snot out of the ring gear and pinon. I have looked at past post on converting the windings to 12 volt but they all seem to be missing something or just are not that clear. Does anyone make just the 12 volt windings that can be used in the T starter or a better diagram on how to rewire? Or is there a less costly 12 volt converted starter then sold by Mac's? If there has been a write up in the Vintage Ford which one?
It wasn't a T, but I had some experience with a "converted" starter on my flathead Mercury. I broke bendix springs regularly even though the starter was supposedly set up for 12 volts. The problem was bad enough that I carried a spare starter wherever I went.
There are probably a couple of electrical experts who can explain this better, but I think what happens is that the "converted" starters (and extended lengths of cable) provide less torque due to voltage drop at the rated current draw. But for the short time that the starter is spinning up and driving the bendix into place, the current is much lower than cranking current. Lower current translates to less voltage drop.
So the converted starters may crank the engine a little more mildly, but I think they are hitting the flywheel nearly as hard as would a regular 6V starter running on 12V.
John Regan, am I off target here ?
We have used Becker's 12V starters with great success. They are a converted Delco unit. They sell them so cheap I don't know how they make any money on them. There have been discussions here about them. Maybe someone can post a link. My dad has converted a couple T starters to 12V and it is quite a bit of work. We don't bother with that anymore.
At one time a person put a post on here that if a person took 50' of number 8 wire in the circuit prior to the starter, it would reduce the thrust of the starter and reduce bendix and fly wheel damage. Has anyone here tried that?
"So the converted starters may crank the engine a little more mildly, but I think they are hitting the flywheel nearly as hard as would a regular 6V starter running on 12V."
I'm not John Regan but that's not the case. Free running speed is about 20% higher on converted 12v starters but so are my standard 6v starters over stock 6v. Engagement speed at start-up is about the same.
Here are the stats Chuck Brant and I plotted when we conducted the tests.
Ron the Coilman
Perhaps you have your ring gear on backwards.
I don't think the gear is on backwards but to tell the truth I will have look at it. There is a section about 3 inches long that the teeth are missing, I think someone forgot to retard the spark.
Whoever set this car up used the bendix spring fix to reduce voltage to the starter. The teeth on the bendix are fine, the head sleeve no longer spins and the bearing sleeve at the front of the bendix is loose.
If it was my car I would just leave it 6 but it's not. I know that you can get 12 volt windings for the Model A starter.
I've had Ken Kopsky rebuild lots of starters and generators for me, and he does great work. He converted some of the starters to be compatible with 12-v electrical systems and I've never had a problem with any of them.
I have seen 6 volt starters used on 12 volts by using a starter bendix spring as a voltage reducer. Just bolt one end of the spring to the starter cable and the other either to the starter hot post or the switch post. I have never used one like this but have seen it done successfully several times.