Spark rod lever orientation

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Model T Ford Forum: Forum 2010: Spark rod lever orientation
Top of pagePrevious messageNext messageBottom of page Link to this message  By John Fenton on Monday, December 06, 2010 - 11:28 am:

I have asked this question before, but got no reply so I will give it another try. My spark rod which runs down the steering column has been twisted.When I fully retard on the quadrant, the small lever at the bottom of the steering column is facing 2 o'clock when viewed looking down the steering column. This provides more rotation of the timer than if the small lever started at say 12 o'clock because as you move the quadrant lever down there is greater travel of the spark rod to the timer.If I pull the quadrant lever all the way down my timing is too far advanced. What is the correct orientation of the small lever at the bottom of the steering column when fully retarded? (my timing when retarded is correct) Thanks. John


Top of pagePrevious messageNext messageBottom of page Link to this message  By scott conger on Monday, December 06, 2010 - 12:19 pm:

John

why not just tweek the spark rod to lengthen it a bit, to provide more retard, and less advance.

Two o'clock sounds about right, but I'm not sitting in any of my cars right now. :-)

scott


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ron Patterson on Monday, December 06, 2010 - 12:42 pm:

John
It is not clear to my why this is a problem, but here are my thoughts.
2 O'clock sound about right and if your initial timing is set at the correct place with the spark lever all the way retarded it makes no difference. This of course assumes the spark rod pull lever is properly secured to the end of the rod.
I'm not sure why you think your timing can become too far advanced. When driving you are controlling the spark advance with the spark lever and will find the optimal place it runs best depending upon engine speed. This is true regardless of battery, magneto or distributor operation.
In any case here is an article we prepared many years ago that shows how the entire Model T ignition system and spark timing works; Including proper initial advance setting, the range of movement of the spark lever, pull rod and timer case to full ignition advance.
The Model T Ignition System and Spark Timing
Good luck
Ron the Coilman


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Monday, December 06, 2010 - 12:58 pm:

Simple answer. adjust the rod between the column to the timer to get proper retard when the lever is all the way up. This would occur when the piston is just past top dead center. This adjustment is made by bending the rod between the column and the timer. Lengthing it would retard, and shortening would advance. When you get the retard set properly it will start without a "kick". Then when you drive, pull the lever down to the point where you get maximum power without surging or knocking at whatever speed you drive. Most of the time the lever will not be all the way down when driving, but will range from half way to 3/4 of the way down. Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dick Lodge - St Louis MO on Monday, December 06, 2010 - 01:05 pm:

Unless they change the law, you're not allowed to ask about the spark rod's orientation and the spark rod is not allowed to tell you... :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Fenton on Monday, December 06, 2010 - 02:29 pm:

Thanks everyone who replied. I didn't really expect to get THE answer. It's just that I have read about people driving Ts and pulling both levers all the way down for top speed. I have to keep mine not more than 5/8 of the quadrant available. Not a problem for me as I can tell where the sweet spot is. If someone else drives my T then it may get too far advanced. Fully retarded is correct, so possibly I should install a stop on the quadrant. Thanks again. John.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Monday, December 06, 2010 - 03:24 pm:

John,

You bring up an interesting point. I think your confusion stems from the common misconception that there is a "correct" position for the spark lever to be during normal running. Yes, there IS a correct position but it differs with every car depending on how the system was set-up and adjusted, what timer you're using etc. There are no hard rules such as, "All the way down" or "3/4 down". As you have now learned, the correct position is that "sweet spot", regardless of the actual spark lever position. (Really that's not 100% true. The lever position should still be such that you can adequately retard the timing for safe starting.)

I guess as the T's came off the assembly line, with brand new and identical parts, you probably could count on a common spark position for all or most cars.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Fenton on Monday, December 06, 2010 - 04:01 pm:

That's it Dick----Don't ask don't tell.


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