Being a proper coils man, I am finding my way about using the setup on my new Fordor, which is 12v with Texas T Parts dis%^&*^tor and a Z head. I don't know if everything else in the motor is stock, let's assume it is.
It seems to be a Bosch 009 unit with the centrifugal advance disabled. I was thinking of putting the timing light on it and establishing the ideal max advance, then fixing a stop on the spark lever to stop anyone over-advancing it. What figure would anyone suggest?
Once I've shaken the car down and decided if it's a keeper, I will look to put it back on coils, but that's down the road. First I need to debug what I have.
Optimum advance varies with rpm and load, so there is only compromise. Set the advance with the seat of your pants. Too much advance will tell you with reduced power before you hurt it. Too little advance reduces power also.
With a Z head, maybe 25 degrees BTDC at cruise.
Maybe 30 degrees might be better, as you can always retard it a bit if needed.
How you doin' Ralph?
I have 2 T's with Z heads and original coils. My unofficial observations are that the higher compression Z head needs 4 or 5 degrees less spark advance than an original T head to give best results. A distributor gives you more latitude to find the timing sweet spot. YMMV and I am not using a distributor on any of my cars.
Thanks for the help. gents, that'll help me with initial setting. I haven't got any plates for it yet, I'll do some experimenting when I get it out on the road.
I just put the engine back into my '24. It has a distributor. I set number one at top dead center, check to see where the rotor was pointing with the timing lever all the way up. I disengaged the distributor from the cam gear. Set the rotor pointing toward number 1 plug and tightened everything back up. Put the carb back on, hooked up gas and choked it a couple of times. It fired right up. That's the easiest way I can tell you about my experience with setting up the Texas T distributor. There may be other issues, but this should get you in the ball park for the timing of the distributor. Seems odd that it ran and then quit.
I have had the distributor gear on the cam shaft tighten up during rotation and screwed up the timing. You may want to check that too.
This car is running on six volt. I have another on a distributor on 12 volts and had the internal resistor in the coil go bad. Might want to check that as well.
It's running fine Tom, my debugging comment was about the usual problems of buying a car and learning its idiosyncrasies, as well as what the previous owner messed up. I will take your point about things going bad: I intend to get a set of spare points, condenser, cap etc.
If you are running 12 volts and no ballast resistor keep a spare coil under the seat. You will need it some day.
Yes I know the TTP coils are marked "No ballast resistor needed".
If the distributor advance is not enough, your engine will soon over heat.
If it is too much your engine will kick back rather than start easily.
With the Texas T distributor, the spark rod does never need to be advanced more than half way.
Too much advance will make your engine sound like it is fighting itself to stay running.
My understanding of timing as follows
Optimum idle speed timing; use a intake manifold vacumn gauge and adjust the timing for maximum vacumn.
30 degrees is generally the maximum advance and generally should be achieved by about 2000 rpm
These are good "rules of thumb" for ordinary 4 cycle engines.