QuestionQUESTION: I'm doing a tune up of my Model A and have the service books for it. I'd like to use a dwell meter to set the points a little more accurately rather than just using a feeler gauge.
I don't see the specs. for the dwell angle listed in the literature. What would the correct dwell angle be for this stock 1930 FORD ignition system?
Thanks. Bob.
ANSWER: Bob, I only use the light to time the A engine. I find it is very accurate. It is described in the mechanic's handbook on the Model A written by les andrews. A very good book and I hope you have it.
I won't explain it all here, but you connect a light to ground and the moving arm of the points. Have the #1 piston at TDC and rotate the cam clockwise (with the key on, and the spark lever full up) until the light goes out. (The rotor is near the front right pin on the distributor horn, that is #1 plug.) With the points open, the arm is hot, and when they are closed, the arm is grounded. So, the light lights when the points are open, and goes out as they close.
Here is what I do, when you get it to where the light just goes out, tighten the cam screw. Then pull the spark lever down two notches and the light should light. If you get it to do this, you timing is perfect and a dwell meter can do no better.
I can't answer your question, but that is the way we all do it.
Good luck and have fun.
jack
---------- FOLLOW-UP ----------
QUESTION: Jack;
Thanks for the information regarding timing the ignition on the A. I'm familiar with the timing procedure although I use a VOM rather than the light bulb. Same result, different instrument to obtain it.
My question, which I guess will remain unanswered, is what is the dwell angle for the A considering that the points are supposed to be set at about .018?
I guess it's not all that critical and using a feeler gauge to gap the points is sufficient. I just thought that since using the feeler gauge does require some finesse and creative guesswork sometime, it would be nice to be able to double check the setting using a more accurate method such as a dwell meter.
Thanks again.
Bob
AnswerI don't know how to do that, but the A is very tolerent of point gaps. We usually set them to a tight 0.020 to give room for the points to close with mileage. What some of the guys have found is a wobble of the cam due to a worn upper bushing. Grab your cam, and if yuou can move it from side to side, replace the upper bushing. Henry did not design a way to lube it. Most of us have drilled a cross hole in the shaft just above the upper bushing, then a hole down the center of the shaft, then a hole in the screw. This will get oil to that bushing.
Good luck
jack
