Watched Chasing Classic Cars this morning and Wayne ships his Bently mags out to be charged and serviced. The shop owner is making conversation and asks Wayne if he leaves his timing advanced or retarded during storage. Like the setting would somehow affect the magnetic charge in the mags.
Unfortunately, they never discuss it again. But it got me thinking. Is there a proper timing setting for leaving the T parked or stored for a long period, such as a few winter months?
I'll hang up and listen.
Makes no difference where the spark lever is set when you park or store the car.
However, it's a good habit to push the spark lever up right before or after shutting off the motor in case you forget to retard the spark next time you crank the car.
I always leave mine retarded, and If SaraJane has had Visitors I always check the timing before trying to crank her!
Not sure if I do this "right", but I just put the levers where I want them
when I give it the next crank when getting out of the truck.
It's not like the coil is firing when the engine is stopped so the points are not being pulled closed to complete the circuit even if the key was left on in the magneto position. The magnets stop where they stop and there will be about the same magnetic pull (or push) all the way around.
I thought it was an odd question posed by the magnet expert, but I didn't know if there was a reason for it. Guess not.
You don't need to worry about this so long as you have a 120 volt degausser . . . ;- )
I have read somewhere (although I haven't been able to find it yet) that there is a preferred position for the rotor when stopped on the early "horseshoe magnet" magnetos that were used on some brass era cars. Supposed to act like a keeper and reduce the loss of magnetism of the permanent "horseshoe" magnets. From this diagram, it looks like positions A and E would be the preferred positions.
?? This is mighty interesting vis-a-vis the "horseshoe" magneto. That type was on a Case model D tractor I ran for years, but there was no manual spark control - I guess this detail is just another example of Model T superiority ? Integral magneto - (see the sales literature)
I found the source for the info in my previous post, it is discussed in my 1925 Dyke's manual, page 312. The text confirms what I said above, positions A and C are the best positions for maintaining the magnets' charge.
I'm not questioning or doubting what you stated above. I just don't quite understand why A and C are best. Also, in your first post you state A and E (not C) would be best. Is it all 3? Lastly, how does the driver of a car equipped with this type of mag know where to set the advance when parked. Is the mag open to be able to see the position of the armature?
Given the physics of the Model T timer set-up, I can think of only one consideration, which isn't exactly on-point about your question:
If you have a "flapper" type timer, and you stop the engine with the timing advanced, and then shove the lever up before starting, you run the risk of straining the parts. The flapper can get caught behind one of its contacts, and possibly bend something.
For this reason only, it makes sense to retard the spark while the engine is still turning.
But I can't think of any other reason it would matter where the timing lever is, when the engine is not turning.
Oops Gary, I meant A and E in my second post, same as the first post, my goof.
The text in Dyke's said that parking the rotor in positions A and E gave a more direct path for the magnetic flux lines, thereby preserving the magnet's charge. Other positions resulted in a less direct path, which over time would allow the magnets to gradually lose their charge.