|
Sponsored Links (Register now to hide all advertisements) |
|
|
Thread Tools | Display Modes |
|
09-19-2020, 02:02 PM | #1 |
Senior Member
Join Date: Nov 2010
Location: SPRUCE PINE NC
Posts: 446
|
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?
__________________
Why is there never enough time to do it right, but always enough time to do it over!!! |
09-19-2020, 02:18 PM | #2 |
Senior Member
|
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.
|
Sponsored Links (Register now to hide all advertisements) |
|
09-19-2020, 03:24 PM | #3 |
Senior Member
Join Date: May 2010
Location: Largo Florida
Posts: 7,225
|
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. |
09-19-2020, 03:28 PM | #4 | |
Senior Member
Join Date: May 2010
Location: Young Harris, GA
Posts: 1,808
|
Re: Ignition timing question
Quote:
.
__________________
Jim Cannon Former MAFCA Technical Director "Have a Model A day!" |
|
09-19-2020, 04:55 PM | #5 | |
Senior Member
Join Date: May 2010
Location: Largo Florida
Posts: 7,225
|
Re: Ignition timing question
Quote:
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. |
|
09-19-2020, 03:26 PM | #6 |
Senior Member
Join Date: May 2010
Location: Young Harris, GA
Posts: 1,808
|
Re: Ignition timing question
Sponsored Links (Register now to hide all advertisements)
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.)
__________________
Jim Cannon Former MAFCA Technical Director "Have a Model A day!" |
09-19-2020, 04:12 PM | #7 |
Senior Member
Join Date: Nov 2011
Location: CA
Posts: 104
|
Re: Ignition timing question
I have a hard time feeling the dimple.
|
09-19-2020, 07:10 PM | #8 |
Senior Member
Join Date: Feb 2011
Location: Lincoln, Nebraska
Posts: 1,905
|
Re: Ignition timing question
Instead of using the timing pin use a short phillip's head screwdriver to find the dimple.
__________________
Dave / Lincoln Nebraska |
09-22-2020, 10:52 AM | #9 |
Senior Member
Join Date: Nov 2015
Location: Tennessee
Posts: 714
|
Re: Ignition timing question
|
09-30-2020, 01:22 PM | #10 |
Senior Member
Join Date: Jun 2015
Posts: 1,414
|
Re: Ignition timing question
|
09-19-2020, 05:55 PM | #11 |
Senior Member
Join Date: Jun 2014
Location: Land of Lincoln
Posts: 3,114
|
Re: Ignition timing question
Adjust the points gap first before monkeying around timing, I like Tom Wesenberg's set it and forget it !
__________________
Don't force it with a little hammer tap, tap, tap get a bigger hammer tap done |
09-19-2020, 08:06 PM | #12 |
Senior Member
Join Date: May 2010
Location: 215 E. 6th Street Northport, Michigan 49670
Posts: 933
|
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.
__________________
Bob from Northport Northport, Michigan |
09-19-2020, 09:02 PM | #13 | |
Senior Member
Join Date: Nov 2010
Location: SPRUCE PINE NC
Posts: 446
|
Re: Ignition timing question
Quote:
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.
__________________
Why is there never enough time to do it right, but always enough time to do it over!!! |
|
10-02-2020, 10:36 AM | #14 | |
Senior Member
Join Date: Jul 2010
Location: Pennsylvania
Posts: 1,096
|
Re: Ignition timing question
Quote:
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. |
|
10-02-2020, 05:53 PM | #15 | |
Senior Member
Join Date: Nov 2010
Location: SPRUCE PINE NC
Posts: 446
|
Re: Ignition timing question
Quote:
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.
__________________
Why is there never enough time to do it right, but always enough time to do it over!!! |
|
09-30-2020, 12:59 PM | #16 | ||
Senior Member
Join Date: Nov 2010
Location: SPRUCE PINE NC
Posts: 446
|
Re: Ignition timing question
Quote:
Quote:
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!
__________________
Why is there never enough time to do it right, but always enough time to do it over!!! |
||
09-30-2020, 02:38 PM | #17 | |
Senior Member
Join Date: May 2010
Location: Young Harris, GA
Posts: 1,808
|
Re: Ignition timing question
Quote:
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. .
__________________
Jim Cannon Former MAFCA Technical Director "Have a Model A day!" |
|
09-30-2020, 03:24 PM | #18 | |
Senior Member
Join Date: May 2010
Location: Largo Florida
Posts: 7,225
|
Re: Ignition timing question
Quote:
Yep. At first he had 20º to 25º advance. After adjusting points and timing he now has 50º. It doesn't compute. |
|
09-30-2020, 08:57 PM | #19 | |
Senior Member
Join Date: Nov 2010
Location: SPRUCE PINE NC
Posts: 446
|
Re: Ignition timing question
Quote:
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!
__________________
Why is there never enough time to do it right, but always enough time to do it over!!! |
|
10-01-2020, 10:37 AM | #20 | |
Senior Member
Join Date: May 2010
Location: Young Harris, GA
Posts: 1,808
|
Re: Ignition timing question
Quote:
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". .
__________________
Jim Cannon Former MAFCA Technical Director "Have a Model A day!" |
|
Thread Tools | |
Display Modes | |
|
|
Sponsored Links (Register now to hide all advertisements) |
|