Best Timer for Running on Magneto?

Greg Jones

Greg Jones

Well-known member
I just rebuilt my 26 Model T engine. I have been messing with Model T's and A's since I was 12, and I am now 58. Anyway, I meticulously rebuilt my magneto. New charged magnets, rebuilt field coil, used the gap gauge to set it up. Years before when I rebuilt the magneto, I just grabbed a magnet and slapped it on the flywheel and the magneto put out as much juice as Grand Coulee Dam. Then the car sat for years and the magnets went limp. Now after meticulously setting up the magneto, the car sputters and carries on when I switch to magneto. Rebuilt switch from Ben in Georgia, rebuilt coils from Coilman. The only thing I have differently is put on an Anderson timer. Is the roller timer better for use on magneto or does it make a difference. I need to dig out my testing equipment of course to measure mag output but was just wondering about the timer.
 
Original roller timers work great too, as do the original New Day, and ANCO timers. I use original roller timers in all of my T's.

There are some reproduction roller timers that are very poorly made.

Tony Wiltshire makes a reproduction of the 1917 - 1920 Ford brush timer that reportedly works well. I have not tried one, but plan to. Click here:
http://www.twcomponents.com/#!

The reproduction ANCO Timers also have a good reputation. Again I have not tried one. Here's a link:
https://www.modeltford.com/item/3221ANCO.aspx
 
As Royce says, all the timers he mentioned work well. My preference is the New Day, but the Ford roller timer on my touring works fine. I doubt that the timer has anything to do with your magneto problem. My first guess would be a poor switch connection, but yours is rebuilt. Maybe a poor contact at the mag post. Also check for a loose wire. I was having an intermittent electrical problem and found that the terminal block was cracked so that a loose screw was causing poor contact. But do that bulb test on the MAG. You want to know if it's putting out the juice.
 
One thing with the roller timer, you have to make sure that your engine front cover is aligned to the camshaft correctly. They sell a tool to check that. I know, because my cover wasn't aligned, and the roller wasn't concentric with the timer body, and buggered up the timer. The New Day Timer is more forgiving, but they're not made any more- just the brushes are available.
 
I think the Anderson of all timers really need to have the front cover centered to the cam shaft. But you asked about sputtering when you switch to mag. I would do as Steve says and check your mag output and connections. Make sure you are pulling the spark lever down to the engines sweet spot. Is your Anderson one of the new ones? If it's an old one could be that the contacts in it are bent and need to be adjusted. Do you have a different timer you could try?
How was the thrust on your rear main?
What clearance did you set it to?
What gap did you set the magnets and coil ring to?
 
Rear thrust set to 0.002" and this was one of the main reasons for opening up the engine. I don't recall clearances I used (memory tells me magnet gap set at 0.025" or was it 0.035", whichever the shop manual specified) but I meticulously followed the Model T shop manual-I photocopied relevant pages and had them in the shop so I didn't worry about getting the book greasy. I made sure gap top and bottom was within specs, allowing for the slight weight deflection you get at the bottom of the flywheel. I bought the gap gauge which works great. I am wondering about my coil box at this point. Or perhaps on assembly I messed up a field coil-hopefully not! I went to pretty extreme measures to R&R and set everything up by the book. Coil box never gave me problems before, but who knows after all this time. Also tried both a repro mag post and a NOS one for the 26-27. Last night, I was able to idle on magneto pretty decently but only if in one precise spark setting. Anyway, to be continued.....
 
The coil box is fed with only one wire from the switch so if it runs good on battery you can rule out the coil box. .002 might be a little tight on the thrust but it should work. Bottom line, check your mag output and check the switch. Use your meter to make sure when you switch to mag it is completing the circuit. Jiggle the key a little when you check. Just because it's rebuilt does on mean it could not have issues.
Did you install the starter WITHOUT the Bendix on it?
 
I did install the starter without the bendix on it. It runs great on battery so guess that eliminates the coil box. I agree even Ben the switch rebuilder cautioned me that he rebuilds these switches (he's the fellow who rebuilds them for Lang's and others) but that does not mean there might not be problems crop up with it. I know the repro switch is garbage, I can confirm that. Will try another switch (being the anal type I had him rebuild 4 switches). Have a wedding to attend out of town this weekend so can't play with it for a while but will let you all know what I find.
 
I have repro Anderson timers on both of my T's and have been quite pleased with them. However I've been reading on the MTFCA forum that several T owners have replaced their Anderson timers with the TW carbon brush type and have noticed considerable improvement.
 
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