MTFCA Forum

What are the measurements for a timer adjustment made from scrap aluminum? Need center to center distance and diameter of holes.
Thanks

Dennis

be aware that this timer gauge is good for ONLY original Ford timers and CANNOT be trusted to set up any other timer accurately.

Best tool I know to set the ignition is this one.
https://www.snydersantiqueauto.com/prod ... &cat=41853

Had the experience yesterday.
With the two hole caliber the Anderson timer on the car was 5/8" wrong in timing. The engine lost power.
Used the tool and set the ignition on 15°BTDC. Power was back.
Just my opinion.

Andre
Belgium

AndreFordT wrote: ↑

Fri Oct 08, 2021 5:17 am

Best tool I know to set the ignition is this one.
https://www.snydersantiqueauto.com/prod ... &cat=41853

Had the experience yesterday.
With the two hole caliber the Anderson timer on the car was 5/8" wrong in timing. The engine lost power.
Used the tool and set the ignition on 15°BTDC. Power was back.
Just my opinion.

Andre
Belgium

Great tool but be aware doesn't work with high compression head

What should the center to center distance be when using a New Day type timer on a stock engine? I used 2 1/2" and it did not work well.

You cannot reliably set the timing of a non Ford commutator and a non Ford roller by measuring the distance from a bolt to the commutator rod. There is no shortcut. You must use the piston position to determine actual TDC. If the fully retarded spark lever position allows a spark to fire prior to TDC you have a dangerous situation which may cause the engine to momentarily run backwards during a start, potentially resulting in a broken arm while hand cranking or a damaged bendix when using the electric starter.

To determine TDC, remove a spark plug, insert a long wire into the cylinder, slowly hand crank and watch the wire go up and down, when it reaches the maximum exposed length, you are at TDC, when the wire starts to get shorter you are at past TDC. I set my timer for just past TDC. The piston will have two TDC cycles in a 4 cycle engine, you will want to be at the end of the compression cycle/start of power cycle when doing the test.

Mario
If you use the TW timing setting tool on "Low" head engines you have to cut approximately one half inch off the end of the shaft that goes down the spark plug hole.
Then you will find it will work on any low or high head. .
Ron Patterson

Ford factory setting for Model T initial timing was 15 degrees ATDC.

It doesn't matter which piston is at top dead center on the compression stroke. You just set the timer to buzz at that point. As long as the timer is wired correctly it will work, so after you get it adjusted, with the key to battery, turn the engine very slowly until you hear a buzz and see if the crankcase pin is past straight across.
Norm

If the initial timing is correctly set at 15 degrees ATDC the coils will start to buzz when the crank pin is pointing to at 9:30 and 3:30.

There are two things to consider, as I understand it, aside from being able to adjust the timing when running to suit the engine's requirements: (1) Avoiding damage to the starter, whether it's mechanical or a person. (2) Getting the coils to fire within the higher amplitude portion of the magneto node.

Not to gainsay excellent advice, I wonder if some after-market timers present the same as the stock roller timer ? Years ago, I set up a New Day on the 2-2/2" measurement in ignorance of an actual TDC check with good results. My current Lizzie runs a TW timer which I also set up by measurement, then thanks to this forum, checked via TDC, also correct. Good to know these things !!

Another thing to take into consideration is wear and play in the linkage. If the timer is not in the proper position with the lever all the way up you could have a problem. with play in the linkage, you could have a situation where the timer stops turning as you retard the lever. So check out and replace parts as necessary for minimum play. You might also need a small washer between the timer and the cotter pin.
Norm

Rich Bingham wrote: ↑

Fri Oct 08, 2021 1:37 pm

Not to gainsay excellent advice, I wonder if some after-market timers present the same as the stock roller timer ? Years ago, I set up a New Day on the 2-2/2" measurement in ignorance of an actual TDC check with good results. My current Lizzie runs a TW timer which I also set up by measurement, then thanks to this forum, checked via TDC, also correct. Good to know these things !!

In regards to the new day. The problem is the clocking of the brush, depending on the one you have. Its safer, surer & more accurate to check with the crank pin location. No tooling required. This method works with all timers & distributors.

Here is my theory how this all unfolded during of the original development of the Model T Ford.
If one steps back and looks at the Model T's design in detail it becomes appartant that several considerations came into play.
First, they had to find the place where the magneto current pulses (that were fixed and occurred every 22.5 crankshaft degrees) would occur in a range optimal for engine running performance to meet the requirements of a motor vehicle. I beleive this is why the magnets are advanced from TDC by 7 crankshaft degrees making the first usable current pulse occuring at 4.5 degrees ATDC for starting and the next usable current pulses for running the engine, current pulse that occurs at 18.5 degrees BTDC and the next at 41degrees BTDC.
Second starting the engine had to be safe for the operator. I believe why they set the roller timer first making contact to operate a coil at 15 degrees ATDC with the spark lever fully retarded. So no one could, in theory, not be harmed by inopertune and violent hand crank kick backs.
Lastly the engine had to be safely hand cranked started on the magneto (early Model T''s had no starting motor (but there was a provision on the coilbox for owners to add a battery). With the spark lever all the way retarded you would be trying to hand crank start the engine with the first spark occurring at 26.5 degrees ATDC which would be difficult at best becasue by that time much of the cylinder compression was lost. So Ford recommended to owners (in early Model T operator recommendtions) to advance the spark lever 3-4 clicks on the quadrant so the timer would first spark would occur at 4 degrees ATDC where much of the cylinder compression was still present.
A properly operating Model T can be started and run with the spark occuring at 4.5 degrees ATDC and the engine will immediatley speed up when the spark lever is pulled down and bit so it is running with spak occuring at 18.5 degrees BTDC.
Many years ago Steve Conniff and I jointly wrote the following article to simply describe in laymans terms how all this works.
Quible if you like, but it makes absolute sense.
Ron Patterson

I was just rereading the post the 15°BTDC must be 15° ATDC.

Andre
Belgium