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Old 09-19-2020, 02:02 PM   #1
fred93
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Default Ignition timing question

I will be checking and adjusting (if needed) a friends 30 Coupe ignition timing.

I have read Les Andrews section on timing and I have read many posts here until my eyes started to cross!

My question is: If the timing has been set-up correctly what should I see when using a timing light when the lever is all the way up and also all the way down?
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Old 09-19-2020, 02:18 PM   #2
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Default Re: Ignition timing question

If you are asking what you will see with a regular timing light, you will probably see nothing. If you are asking what you will see with a grounded test light attached to the closed point arm, with the ignition on, the spark advance rod all the way up, and number 1 cylinder is at top dead center, you should not see the test light lit. If that is the case, with the ignition on and a grounded test light attached to the closed point arm, begin to bring down the spark advance rod. The test light should come on when the spark advance is down about 1 or 2 clicks. If that is the case, you ae good to go on the timing. If that is not the case, follow Les Andrews timing method. All of this is done with the timing pin in the dimple of the cam gear.
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Old 09-19-2020, 03:24 PM   #3
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Default Re: Ignition timing question

Timing light ?

It would depend on the type of timing light or if you have a timing strip and pointer set up somewhere.

But, timing should be 0º to close to 40º.
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Old 09-19-2020, 03:28 PM   #4
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Default Re: Ignition timing question

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Originally Posted by Patrick L. View Post
Timing light ?

It would depend on the type of timing light or if you have a timing strip and pointer set up somewhere.

But, timing should be 0º to close to 40º.
I think he means a simple test light that connects between the points arm and ground, to show points closed or open. Not a flashy timing light.



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Old 09-19-2020, 04:55 PM   #5
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Default Re: Ignition timing question

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Originally Posted by Jim/GA View Post
I think he means a simple test light that connects between the points arm and ground, to show points closed or open. Not a flashy timing light.



.




That was the reason for my question. He mentioned timing light and not test light. Two different animals, as we know. It seems many folks here try to use timing lights, so I thought that is what he meant.

I might well have taken his question wrong thought. Probably did. Maybe we'll know soon.

I've never quite understood the confusion over timing these monsters or using a timing light for doing it. But, I try to answer the question as I understand it. This wouldn't be the first time I didn't understand what was being asked.
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Old 09-19-2020, 03:26 PM   #6
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Default Re: Ignition timing question

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The procedure and the observations (what to look for in the light) that Dick M posts is correct. Spot on.

I help lots of people "time" their Model A engines and the most common error I find (the reason they have contacted me) is that they have confused in their head if they want the light on or off with the spark lever all the way up. So instead of having it OFF with lever at the top, and come ON with 2 or 3 clicks, they have it ON at the top, going OFF with a few clicks. That is backwards! When they do that, they are on the wrong side of the cam lobe and the timing is way off.

As a final QC check on your timing, once you think you have it correct and are reassembling everything, gently turn the rotor clockwise with your fingers to take up any slack and the trailing edge, the lower right corner of the big brass tab on the rotor should be opposite pin #1 inside the distributor cap. If it's not close to that pin, you have somehow messed up; do it again. (I do this quick check at the start, right after I get the timing pin dropped into the cam gear, before I loosen anything up. You can spot a lot of timing problems with this one check.)

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Old 09-19-2020, 04:12 PM   #7
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Default Re: Ignition timing question

I have a hard time feeling the dimple.
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Old 09-19-2020, 07:10 PM   #8
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Default Re: Ignition timing question

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Originally Posted by Jeff M View Post
I have a hard time feeling the dimple.
Instead of using the timing pin use a short phillip's head screwdriver to find the dimple.
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Old 09-22-2020, 10:52 AM   #9
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Default Re: Ignition timing question

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Originally Posted by Jeff M View Post
I have a hard time feeling the dimple.
I had one that was so full of crud you could not feel it. had to pull the cover.
If you do be sure to drill the dimple out a little.
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Old 09-30-2020, 01:22 PM   #10
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Default Re: Ignition timing question

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I have a hard time feeling the dimple.
You can use a mechanics mirror ($4-5) and small led light and look inside the cover hole to see the dimple centered (At TDC with rotor close to the #1 distrib cover contact, etc.).
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Old 09-19-2020, 05:55 PM   #11
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Default Re: Ignition timing question

Adjust the points gap first before monkeying around timing, I like Tom Wesenberg's set it and forget it !
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Old 09-19-2020, 08:06 PM   #12
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Default Re: Ignition timing question

If you use a timing light. you will need a degree indicator that mounts to the front of the engine and sits over the crank pulley. NuRex sells them. The timing can be adjusted in small increments if you have it set manually to a close degree. Full retard should be about -5 degrees. Full advance should be about 22-24 degrees. NEVER 40 degrees as someone suggested. You would burn the engine up and melt the exhaust. My shop times every car to those specs and they all run and start great.
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Old 09-19-2020, 09:02 PM   #13
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Default Re: Ignition timing question

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Originally Posted by Bob from Northport View Post
If you use a timing light. you will need a degree indicator that mounts to the front of the engine and sits over the crank pulley. NuRex sells them. The timing can be adjusted in small increments if you have it set manually to a close degree. Full retard should be about -5 degrees. Full advance should be about 22-24 degrees. NEVER 40 degrees as someone suggested. You would burn the engine up and melt the exhaust. My shop times every car to those specs and they all run and start great.
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.
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File Type: jpg IMG_7324.jpg (22.6 KB, 44 views)
File Type: jpg IMG_7351.jpg (78.4 KB, 75 views)
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Old 10-02-2020, 10:36 AM   #14
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Default Re: Ignition timing question

Quote:
Originally Posted by fred93 View Post
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.
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Old 10-02-2020, 05:53 PM   #15
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Default Re: Ignition timing question

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Originally Posted by Will N View Post
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.
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Old 09-30-2020, 12:59 PM   #16
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Default Re: Ignition timing question

Quote:
Originally Posted by captndan View Post
I had one that was so full of crud you could not feel it. had to pull the cover.
If you do be sure to drill the dimple out a little.
Quote:
Originally Posted by Bob from Northport View Post
If you use a timing light. you will need a degree indicator that mounts to the front of the engine and sits over the crank pulley. NuRex sells them. The timing can be adjusted in small increments if you have it set manually to a close degree. Full retard should be about -5 degrees. Full advance should be about 22-24 degrees. NEVER 40 degrees as someone suggested. You would burn the engine up and melt the exhaust. My shop times every car to those specs and they all run and start great.
Thanks for your reply--- I finally got back to the timing read out--

With the NuRex degree indicator--

1--With the timing light hooked up (and without making any adjustments) the timing with the lever all the way up, the reading was approximately 25* to 30* retarded.

With the lever all the way down, the reading was 5* retarded.

2--I adjusted the points (to .018") and replaced the rotor (it just did not fit snug against the distributor shaft) I also adjusted the rotor to cap gap to .025" .

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!
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Old 09-30-2020, 02:38 PM   #17
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Default Re: Ignition timing question

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Originally Posted by fred93 View Post
<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.

.
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Old 09-30-2020, 03:24 PM   #18
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Default Re: Ignition timing question

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Originally Posted by Jim/GA View Post
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.
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Old 09-30-2020, 08:57 PM   #19
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Default Re: Ignition timing question

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Originally Posted by Jim/GA View Post
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!
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File Type: jpg Nu-Rex.jpg (46.9 KB, 34 views)
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Old 10-01-2020, 10:37 AM   #20
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Default Re: Ignition timing question

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<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".

.
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