Over the past few years I have mentioned that I have a Dayco Timer on my T and that the timing rod is a bit shorter than the "other" styles.
I have not shown any pictures of it because I didn't think to take pictures went working on other things and was lazy, so here it is.
The first two are the inside and the other is the cam which uses the little pin to make sure it is in the correct location.
The brass plungers are spring loaded and move freely.
I wipe the inside of the timer a few times each year, do not oil it and have a modern seal behind the shield
Apparently manufacturing aftermarket timers for the Model T was a major industry. With all the various versions of rollers, flappers, and brushes, it seems there must have been hundreds of outfits that thought they had a better idea.
I understand the brushes, but I don't see any non-conductor on the rotor to break the circuit. How does that work?
Steve -- your marvelous!
Your questions make me think and help me to better understand what is happening.
I was thinking the plungers made contact to fire but now I am thinking they loose contact with the cam to fire.
Which makes more sense because of the large area the plunges contact it. .
The non-contact area may be on the back side -
The thumbscrew terminals are insulated from the spring loaded plungers.
When the cam lobe pushes down on a plunger, it makes contact with a point on the end of the terminal and completes the circuit for that terminal.
Actually, it's the contact to ground that fires the plugs. As the roller, brush, or flapper rotates it momentarily completes the circuit as it hits each contact. The Dayco has the brushes stationary and the contact turning, but I would expect to see a small enough contact to hit only one brush at a time. Maybe somebody familiar with this kind of timer can 'splain it to me.
Aha! Erik types faster than I do.
OK -- It completes the circuit to ground as I thought the first time.
All I know is that the timing rod is significantly shorter than the one that I have to use with the carbon bush style I bought from Lang's a few months ago.
It is interesting to note that the current picture on Lang's web site has a place to put oil where the one got does not!
As I recall, TW Components were using original commutator housings in the beginning, then switched to newly manufactured ones, which would account for the missing oil port. You don't need to oil this timer, although it would be nice if it was there for an original look.
That is good to know!