Ignition timing question

[Jim/GA]

Originally Posted by fred93

<snip>
I then adjusted the timing (making it more advanced).

The reading after all that was :

With lever all the way up---5* retarded.

With the lever all the way down--45* advanced.

With the lever half way down---30* advanced.

Seems to me that I need to adjust again so that with the lever all the way down I would have 30* advanced.

Thoughts on this please!

Fred-
The stock Model A distributor spark lever is *supposed* provide a total of 40 crank degrees of timing change (20 degrees of rotor change). So if you are starting at 5* AFTER TDC at the top, moving the timing lever all the way down should bring you to 35* BEFORE TDC.

Please check the readings that you report above again.

You should not be able to go from 5* ATDC to 45* BTDC. That is 50* of change. Something is not right. Maybe you misread something or wrote it down wrong.

.

[Patrick L.]

Originally Posted by Jim/GA

Fred-
The stock Model A distributor spark lever is *supposed* provide a total of 40 crank degrees of timing change (20 degrees of rotor change). So if you are starting at 5* AFTER TDC at the top, moving the timing lever all the way down should bring you to 35* BEFORE TDC.

Please check the readings that you report above again.

You should not be able to go from 5* ATDC to 45* BTDC. That is 50* of change. Something is not right. Maybe you misread something or wrote it down wrong.

.

Yep.
At first he had 20º to 25º advance. After adjusting points and timing he now has 50º. It doesn't compute.

[wmws]

See post 11.

[Patrick L.]

Originally Posted by wmws

See post 11.

??????

Post #3 says the same thing. I just prefer TDC at the starting point and limit the lever travel. I may use about 30º. Apparently 40º doesn't hurt, I just don't go that far.

[marc hildebrant]

I use the method in the owners manual so that handle up is 0 degrees and down is about 40 degrees advance.

Marc

[fred93]

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Originally Posted by Jim/GA

Fred-
The stock Model A distributor spark lever is *supposed* provide a total of 40 crank degrees of timing change (20 degrees of rotor change). So if you are starting at 5* AFTER TDC at the top, moving the timing lever all the way down should bring you to 35* BEFORE TDC.

Please check the readings that you report above again.

You should not be able to go from 5* ATDC to 45* BTDC. That is 50* of change. Something is not right. Maybe you misread something or wrote it down wrong.

.

Thanks for your reply--

Please check post #19 item number 1.That reading was somewhat of a guess because the Nu-Rex degree indicator only goes up to 15* retarded. The reading with the lever all the way down was definitely at 5* retarded because I could see the yellow paint mark line up with the 5* retarded mark on the degree indicator. So that reading may not have been correct.

I did another adjustment today and I came up with 15* retarded with the lever all the way up and 35* advanced with the lever all the way down. That works out to be a total range of 50* from lever up to lever down. That range matches the first adjustment that I made (post #19, item number 2). So that means that the first reading must have been lever up--55* retarded lever down 5* retarded.

That still gives me a total range of 50*. That range seems larger than what it should be?

According to the Nu-Rex instruction sheet "the total range of steering column spark control is approximately 40* of crankshaft travel". Why am I having 50* of travel?

Since this car belongs to a friend of mine I would rather have the total advanced reading at 30* or 35*. He is a "lever up to start and a lever down to drive" type of person, so you can see where I am going with this!

[Patrick L.]

Just for the heck of it set the timing as Ford says. Lever up at TDC. That lever is adjustable in that you can bring it down as far or as little as you want.

[30 Closed Cab PU]

I do not know why you would have 50*. However at the desired max advance lever position perhaps drill a hole in the Quadrant and add a bolt/nut to limit the advance lever? I have seen this done on cars with high compression heads.

[Jim/GA]

Originally Posted by fred93

<snip>
That still gives me a total range of 50*. That range seems larger than what it should be?

According to the Nu-Rex instruction sheet "the total range of steering column spark control is approximately 40* of crankshaft travel". Why am I having 50* of travel?

Look at his distributor body. Look at the slot where the upper plate arm swings back and forth as you advance/retard the spark lever. Compare it to another known good body. It is this slot that actually limits the total change in the spark advance. If this cap has been modified, you can get more total advance than 40*.

That's all I can think of. Maybe swap in another distributor body as a test. You really should not be getting more than 40* change from "up" to "down".

.

[Patrick L.]

Originally Posted by Jim/GA

Look at his distributor body. Look at the slot where the upper plate arm swings back and forth as you advance/retard the spark lever. Compare it to another known good body. It is this slot that actually limits the total change in the spark advance. If this cap has been modified, you can get more total advance than 40*.

That's all I can think of. Maybe swap in another distributor body as a test. You really should not be getting more than 40* change from "up" to "down".

.

Yep, that happens. Timing doesn't get set correctly apparently and to gain more advance the body/housing gets hacked. Or, someone gets to thinking if thats all Ford wants, then, more must be ' more better '.
But it could also be the timing light or the tape.

[Will N]

Originally Posted by fred93

Thanks Bob--Yes I have the NuRex Timing set-up.

The owner is complaining that the car lacks power. I wanted to see where the timing is currently set before I start changing anything.

I set up a "test light" and I checked the timing that way first. I had no light with the lever up all the way. The light did not come on until the lever was almost to the lowest position. I assumed that the timing is way retarded, but I will be hooking up a "timing light" to actually see how far off it really is.

Once I had find where the timing is right now, then I will start making my adjustments.

My reason for the original question was that I wanted to have a target to aim for.

I checked the compression and came up with #1--60psi #2--55psi #3--55psi #4--53psi (these figure were when the engine was cold--I know that it is normally done with the engine at operating temp but I had the spark plugs out to check them and I didn't want to put them back in (hindsight is always better than foresight) I will be checking the compression again at normal temp later).

I noticed that the spark plugs were very sooty, like it has been run too rich, however that could also be caused by incorrect timing? I will be installing new plugs.

I have never seen a timing pin as shown in the first picture in post #12 slide in that deep. Even when it has seated in the dimple, there is usually an 1/8th inch or more of the shaft showing. This one is right down to the base. Is it a stock timing pin? I don't have the measurement handy, but my best guess is that the length of the pin is about 1 1/4 inches from the base to the tip. If your pin is too short and it's bottoming our on the timing cover, it can't drop into the dimple on the timing gear.

[fred93]

Originally Posted by Will N

I have never seen a timing pin as shown in the first picture in post #12 slide in that deep. Even when it has seated in the dimple, there is usually an 1/8th inch or more of the shaft showing. This one is right down to the base. Is it a stock timing pin? I don't have the measurement handy, but my best guess is that the length of the pin is about 1 1/4 inches from the base to the tip. If your pin is too short and it's bottoming our on the timing cover, it can't drop into the dimple on the timing gear.

Thanks for your reply--

I have no idea if the timing pin is stock. I can feel the pin fall into the dimple as I turn the crank, so I know that it is on top dead center.

I don't know why I have 50* of travel but I do have that much. At this point all I need to do is make sure that the advanced figure (with lever all the way down) is not too much advance timing. If 35* is ok then I can leave it the way it is right now. I don't see a problem having too retarded timing when starting the engine?

I can't see where making the slot in the distributor cap bigger would make any difference. The tabs on the steering column are what determines the total travel.

[Bruce of MN]

Originally Posted by 30 Closed Cab PU

I do not know why you would have 50*. However at the desired max advance lever position perhaps drill a hole in the Quadrant and add a bolt/nut to limit the advance lever? I have seen this done on cars with high compression heads.

Here is what I made:

https://www.fordbarn.com/forum/showp...2&postcount=23


One question, is the 50 deg with the dizzy body on? It is only a valid measurement with the body in place.

[Jim/GA]

Originally Posted by Bruce of MN

Here is what I made:

https://www.fordbarn.com/forum/showp...2&postcount=23


One question, is the 50 deg with the dizzy body on? It is only a valid measurement with the body in place.

He took the measurements with a flashing timing light with the engine running. So it had to have a body in place.

I like your stop with a set screw. Very good, simple solution. I will be making me one.

.

[fred93]

Originally Posted by Jim/GA

He took the measurements with a flashing timing light with the engine running. So it had to have a body in place.

I like your stop with a set screw. Very good, simple solution. I will be making me one.

.

Thanks for your reply--

One question--if I leave the setting as it is, the max advance would be 35* is that a problem?

[Jim/GA]

35* is a bit much, but as the points cam follower wears, and the point gap closes, that 35* will go down.

BTW, Ford's May, 1928, Service bulletins says to gap the points 0.018"-0.022". Your 0.018" is going to close down as the cam follower wears. Better to start up around 0.022".

There was an earlier bulletin with a smaller gap specified, but Ford changed it later to be the 18-22.

.

[fred93]

Originally Posted by Jim/GA

35* is a bit much, but as the points cam follower wears, and the point gap closes, that 35* will go down.

BTW, Ford's May, 1928, Service bulletins says to gap the points 0.018"-0.022". Your 0.018" is going to close down as the cam follower wears. Better to start up around 0.022".

There was an earlier bulletin with a smaller gap specified, but Ford changed it later to be the 18-22.

.

Thanks for the service bulletin info-I agree and I will adjust the points to .022"