Background info; I bought my T a few years ago. The generator has always put out about 2 amps, per the gauge. Last night I pulled out the holy Model T Bible and went to work. First I tried to adjust the third brush as described while the generator was still attached. There was no difference in the amperage. I thought about changing generators but decided it was too much like work, so I took swapped cut-outs. It now puts out about 8 amps, while at cruising speed. I will go back and tweek the third brush later.
Once I was done I noticed the engine seamed much quieter. It has always been loud, and as you can see in my profile it is not done, and it has been in this condition for about 2 years. The wife and I always have to talk loudly to each other when we go somewhere. Last night during a little test cruise around the neighborhood we could talk at fairly normal levels and hear each other quite nicely (still had a lot of wind noise). Can a faulty cut-out create that much additional engine noise?
What was the noise like beforehand?
A generator set at 3 - 4 amps it normally about right. At 8 amps you will likely over charge your battery and do more damage then good, more is not always better.
See this thread for some discussion by an expert in the field:
I would pull the generator and check the condition of the gears, i'm just wondering if there chewed up and making noise. and now that there's a bigger load on the generator it's just meshing the gears tighter together and masking the noise.
A bad generator gear can make a lot of noise.
Jason - do what ever you have to do to go back to 2 amps. Like Jim says you are going to fry that old generator at 8 amps.
Find some other Model T people to listen to the car. Model T's often make a lot of noises that are normal. Maybe quieter is not better in your case. As a proud graduate of St Paul Highland Park High School I know there are a lot of good T people in the area.
Any chance that 'cut out' you removed was really a Fun Projects voltage regulator?
Maybe the timing gears have some play, due to worn teeth, and the additional load of the generator overcharging adds pressure that quiets the noise? Worn timing gears can be really loud.
The book said to set it at 12 amps while the engine is at 20 mph, so that is what I aimed for. I can lower the amps fairly easily. I do a lot of short trips and the battery does not keep a good charge and I have to periodically charge it. When the charge is weak it is a lot harder to start.
I can pull the generator and check the gears.
How can you tell if the cut-off is a Fun-Projects voltage regulator? I was going to order a new cut-off to replace the one I used. Is the voltage regulator a better unit???
There are a bunch of good T guys around these parts, I just do not have a lot of time to hang out with them tho.
Where you set the generator is based mainly on when and how much you drive the Model T. If you drive a lot with lights on, you should have the generator set higher, and if you seldom drive it for short runs, the generator should be set higher, but if you regularly drive during daylight hours without lights on, 2 amps is about right.
The 12 amps listed in the book was for back in the day when people made short trips at low speeds. That kind of charge rate on today's roads will overcharge a battery.
There is a way to tell a VR from a cutout. It involves the number of or maybe the position of the rivets on the bottom of the unit. However, I don't remember what it is. A search of the forum would probably turn it up, though.
And yes, if you are going to buy a new cut out, I would go ahead and spring for the voltage regulator. Your 3rd brush sets the maximum charging rate, just like on a cutout, but when your battery doesn't need it, it drops to somewhere between 0 and 2 amps. When you first start the car, the ammeter will read maybe 10 amps or so, but after a few minutes of driving, it will drop to about 2 amps or less. That is why I asked about whether it was a VR, as the 2 amps you mentioned would be about normal for a VR and a charged battery.
Another way to tell would be to turn on the lights with the engine running at a moderate speed. If the ammeter goes negative for just a second and comes back up to 0-2 amps, then it is a voltage regulator. If it drops to 10 amps below your normal reading and stays there (-8 in your case), then it is a cutout.
Here it the VR ID info:
And from John Regan:
"Voltage regulators can indeed be identified from their bases. Since there are T, A, V8, and Model N tractor regulators that look similar - it is important to find which one you have. The most important detail is to make sure you have the correct polarity (positive ground or negative ground type). T regulators are all negative ground and the base looks like the unit pictured on the left. The main thing here it to note there are 5 black fiber washers with 3 of them riveted and 2 of them held by screws. That signifies the unit is negative ground. Next look for any stamping into the metal on the base of the capitol letter "A" or "B". The bent up ground lug in the picture creates a hole in the base and is not the letter A. If you find a letter A on the base then the unit is an 8V unit. If you find the letter B on the base then the unit is a 12V unit. No stamp at all is a 6V unit. The stamping is always somewhere on the underside of the unit and it is not visible when the unit is installed on the generator. It would appear that the left unit in the picture is a 6V negative ground Model T regulator. Those can be Ford scripted on top or not. Electrically the script and non script regulator is the same."