73 Charger 400 4bbl - Ignition timing settings

[rollo1504]

Hey folks!

Very soon I will come to the point to check/adjust the ignition timing at my baby...

So can someone tell me all "how-it-should-be" values 

- Initial timing (idle)
- total timing
- mechanical advance timing

I will get some values with my timing light but actually I don't know what is good, what is bad, its good but there is more possible, its good and thats all

Thank you all

Cheers

Roland

[rollo1504]

... OK... found out that the most important thing is the total timing for the engine and initial timing is just for reference and may change if total time is changed....

... So the question comes up: "What is the total timing to be for my 400 4bbl big block engine"?

Roland

[71charger_fan]

The '77 400 in my '71 Charger likes lots of advance. I've run as much as 52 degrees with no problem. I started out in the mid-30 degree range, but it had no power. I just kept bumping it until it seemed happiest and that's how I wound up with that much timing.

[ODZKing]

I have found there are no two alike. With the gas all over the place as it is today, it is hard to set timing to the numbers.
I tried and mine was pinging. So I had to go by ear using the specs as a starting point. I attached a clip from the 73 service manual with 400 4bbl TQ.
What I do it set it, take it out and try it if it pings, I back it off a bit.  I keep at it until I have enough pickup yet low or no pinging. (Ha! My 67 was set it and forget it!!!)

[rollo1504]

I have found there are no two alike. With the gas all over the place as it is today, it is hard to set timing to the numbers.
I tried and mine was pinging. So I had to go by ear using the specs as a starting point. I attached a clip from the 73 service manual with 400 4bbl TQ.
What I do it set it, take it out and try it if it pings, I back it off a bit.  I keep at it until I have enough pickup yet low or no pinging. (Ha! My 67 was set it and forget it!!!)

Thanks for the picture from the service manual...

Let me say it again so that you guys can tell me if I understood everything correctly...

It shows Ignition Timing (Curb Idle Speed) 7-1/2° BTC +-2,5°) <<=== So this means as follows:

- Disconnect vacuum line
- Plug vacuum line of distributor
- Plug vacuum connector of carburetor
- Connect timing light
- Start and let engine run until it is warmed up (3-5 minutes)
- Activate Parking Brake
- Put tranny in DRIVE ==> This is curb idle speed Question: How many RPM at mit 400 4bbl charger is Idle? 950 RPM?
  (Do not know actually how to measure the RPM as my instrument cluster has not tach it has a clock :-(

- Set ignition timing to 5° BEFORE TDC correct? => Calc: 7-1/2° BTC -2,5° == 5°         <<<<<      Is this calc correct? Or did I oversee/misunderstood anything?

- Total Timing: Then put engine RPM between 2500 and 3500 and set timing minimum to 35 BEFORE TDC
  And here I don't understand the former replies anymore.... It can be possible that I need more than 35 BEFORE TDC but how do i notice where the limit is?
Please correct it if I am wrong....

I know that ODZKing tried to explain it but I did not understand the saying mentioned below (Sorry for that)

@ODZKing: Sorry Buddy but I do not understand 100% this phrase: ... " I keep at it until I have enough pickup yet low or no pinging."
What means enough pickup yet low or no pinging....

Can anyone provide a useful youtube link where the pinging is noticable? I don't know how pinging sounds....

Definition "pinging engine": This means that ignition time is set wrong as then the spark fires BEFORE TDC correct?

BY THE WAY:

I made another video in better sound quality... Please have a look and tell me if you hear something wrong or share your opinions, suggestions etc.

I am very thankful for all kind of help....

Look at this: https://youtu.be/dpPauri6vzg     (Hope this time the link works)

Thank you guys

Cheers Roland

[ODZKing]

What I meant by "keep at it" is I set it initially, then take it on the road and punch it. If it pings, back to the garage and back it off. And I continue to do that until I have it so it doesn't ping. Once I have found that spot I move it back just by a little bit. It works for me.
Advance and retard the timing. One of the folks here can explain that because it has always confused me too. Advance to me should be + but I believe it is the other way around.
Anyway that is how I set mine.  Keep in mind gas and octane. I only set mine on 93 octane gasoline.

[justcruisin]

As stated - every engine wants a different setting. A lot depends on your engine specs, a big cam will want lots of initial but generally the total timing is often around the same. Most engines I have messed with benefit from more initial than the factory specs.
I disconnect the vacuum for testing ( I actually don't run vacuum at all), bring the revs up to find max mechanical and set that to 35, let it idle and check your initial. If it's a stock engine you may want more mechanical or maybe less if it's a hot engine. I found that a stock motor seems to like around 14 degrees and as much as 38 total - but every engine is different.
It is best to have a distributor that you can adjust the total mechanical so you can limit it's travel and still run a good amount of initial. A well marked balancer or a dial back timing light is a good idea.
As said do some road testing for audible ping - plug inspections also.

[XH29N0G]

What Justcruisin says.  but one more comment, I do not believe you need to put it in drive to set the idle timing.  I think it will be fine in park.  Since you need to be at the front of the car to see the timing mark, it also is a little safer. 

The basic idea is to advance the timing to a range that is below the point at which it starts to detonate/ping.  When that occurs there is potential damage to the engine and lost performance.  That point depends on a variety of factors that are engine dependent, gas dependent, dynamic compression dependent, depend on spark plugs, even how clean the cylinders are.  So you start with a ballpark and them work from there. 

For what it is worth.  My original engine ran fine up to 36-38 total.  With a rebuild, I cannot get mine to run above 32-34 degrees total advance without it pinging. 

The initial timing (at idle) has a spec and unless you can adjust your distributor will simply depend on the total you dial in.  If you want to get fancy, you can change the difference between initial and total and also how fast the total comes in.  How you do this depends on the distributor you have.  I would leave it if it works, but there is always the option of tinkering more and more.

[71charger_fan]

As stated, at this point in time, no two 400s are likely to be the same given modifications likely made over the years. Plus, factor in that fuel formulations vary. The optimal timing for my engine here in MD might not work in CA. Mine was a dog at 36 BTC total but really woke up when I got it to the mid-40-degree range. My best quarter mile time came at 52 degrees.

[rollo1504]

Thanks for all the comments guys!

Now it is just a little bit more clear to me 

Before I touch the timing I was aiming for finding the timing mark on my engine and I could find it but its not looking like the most other timing marks I found in the internet...

It was very difficult to get a picture in good quality so I made a drawing.

Please look at it and confirm my theory....

If you look at this picture, you can see how it looks like at my engine. Before I start with the timing light to adjust it I have just a question before I do it.

My distributor rotates COUNTERCLOCKWISE. So that means:

Retard Timing = Rotate Distributor COUNTERClockwise (Direction RED Arrow)
Advance Timing = Rotate Distributor CLOCKWISE (Direction GREEN Arrow)

Is that correct?

By the way: Is my drawing correct -> Especially the point that BEFORE = Retard and AFTER = ADVANCE

OR IS IT REVERSEROUND?

So If I take all your comments together I assume I will have to do as follows:

Total Timing:
- Motor in idle and in PARK
- Motor must be warmed up
- Disconnect vacuum from dist at carb
- Run motor around 2500 - 3000 RPM
- Rotate Distributor

So that would mean that if I will rotate the dist CLOCKWISE the balancer mark will go to the RIGHT heading towards the "AFTER" spot in my drawing.... Correct?
Vice Versa if I will rotate the dist COUNTERCLOCKWISE the balancer mark will go to the LEFT heading towards the "BEFORE" spot in my drawing.... Correct?

And now for me the MOST IMPORTANT Question:

What is my main goal -> Getting the Timing mark towards BEFORE or towards AFTER on my balancer mark?

Thank you guys!

You are really great people who are willing to help a poor IT guy without mechanical pre-knowledge base to realize his dream to drive down the roads with a Dodge Charger 

Cheers Roland

[rollo1504]

... Or is it as asked before REVERSE ROUND?

Thanks

[justcruisin]

Distributor rotation is - turn clockwise to advance timing. (balancer mark moves to the left looking from the front -  towards passenger side)
Your second drawing is correct. Looking from the front of the engine, the marks to the left are advance, the line on the balancer (TDC) needs to be somewhere between 10 - 15 (presuming a stock engine, more if modified) in the advance side of the marks.
If you are using a non dial back timing light you will need to mark your balancer in order to read total timing. Some self adhesive timing tape will work.

[rollo1504]

Distributor rotation is - turn clockwise to advance timing. (balancer mark moves to the left looking from the front -  towards passenger side)
Your second drawing is correct. Looking from the front of the engine, the marks to the left are advance, the line on the balancer (TDC) needs to be somewhere between 10 - 15 (presuming a stock engine, more if modified) in the advance side of the marks.
If you are using a non dial back timing light you will need to mark your balancer in order to read total timing. Some self adhesive timing tape will work.

Thank you very much!

Now I understand THIS part of setting the ignition timing 

Roland

[rollo1504]

and now the next question...

HOW DOES THE VACCUM ADVANCE TAKE EFFECT?

I understand how the mechanical advance with the springs inside the distributor works but I could not figure out whats the purpose of the vaccuum advance?

Is the vacuum advance happening AFTER mechanical advance or at the same time or how does this work? Is the vacuum advance NEEDED/NECESSARY?
Is it possible to check if vaccuum advance diaphragm is working correctly by measuring? I know if I disconnect the vacuum advance hose at the carb and I connect the vacuum gauge only direct to the carb I can measure how much vacuum the carb produces. What if I connect it INLINE (between carb and vacuum diaphragm of dist) .... Is it possible to get some informative readings?

Thanks for the explanations!

Cheers Roland

[alfaitalia]

At part throttle, high manifold vacuum moves the diaphragm in the vacuum advance canister on the distributor to add more timing. But at WOT, the vacuum drops to near zero and vacuum advance is removed and the total timing then is established by the initial plus the mechanical advance.

[rollo1504]

At part throttle, high manifold vacuum moves the diaphragm in the vacuum advance canister on the distributor to add more timing. But at WOT, the vacuum drops to near zero and vacuum advance is removed and the total timing then is established by the initial plus the mechanical advance.

So that means ideally after vaccuum drops to zero the timing stays the same when established by initial + mechanical ?

By the way: Thank you for the explanation... I understand now the purpose of it.... Maybe in 3-10 years I will be a mopar expert....as knowledge grows day by day ... AND I LIKE IT! 

Cheers 

Roland

[alfaitalia]

Yes.

Me too.....Ive been around cars, old and new my whole life.....but only Mopar for the last year or so. Learning fast on here though. Lots of stuff like timing, brakes etc etc is pretty much the same whatever the marque.

[rollo1504]

I also like the Mopar-Technology as there is almost NO elctronics which makes it possible to "normal" people like me to understand things and work on it in DIY style....

[alfaitalia]

yep.....not quite the same on my canbus equipped Merc and VW....where you cant even add a light or change to a pattern window motor with a fault light pinging up on the dash!!

[rollo1504]

Distributor rotation is - turn clockwise to advance timing. (balancer mark moves to the left looking from the front -  towards passenger side)
Your second drawing is correct. Looking from the front of the engine, the marks to the left are advance, the line on the balancer (TDC) needs to be somewhere between 10 - 15 (presuming a stock engine, more if modified) in the advance side of the marks.
If you are using a non dial back timing light you will need to mark your balancer in order to read total timing. Some self adhesive timing tape will work.

Mmmmhhh guys... Today I "tried" to adjust ignition timing but I think there is something wrong with it or I am misunderstanding something....

With more or less idle RPM (I dont have a RPM Tacho) I was rotating the dist clockwise to advance the timing and the balancer mark moved to the left - OK so far

BUT then If I rev up the RPM the balancer mark moves towards TDC? I should move more away from TDC or do I misunderstand something?

I do not know if this information would be important for you to know but my balancer mark is on the left side of the engine (viewed from engine front) and NOT on the right side as shown in all videos on youtube....

So in my case If I advance the timing by rotating dist clockwise the balancer mark moves down to the left heading towards the word BEFORE on the metal plate.... but again If I then rev the engine up the balancer moves up and passes TDC and goes to the right.....

I tried vice versa and by rotating the dist counterclockwise then the balancer mark moved to the right after TDC towards the word AFTER on the metal plate and the engine sounds to run much better....?

In case of revving up the engine the balancer mark should move more to the left or not as we need earlier ignition???....

I am lost a little bit...

Another thing is if I rev then the eninge up to WOT I have some detonations coming out from the carb... It is not a backfire only detonations and those only If I it is set to WOT and sets there for 2-3 seconds.... Is this a carb issue concernig secondary's??

Thank you for your help guys

Roland

PS: Also could notice if I loosen up the dist it is wobbling... I assume this is also not good.... If you want I can make a video for better understanding....

[rollo1504]

Found this video of setting the ignition timing....

https://www.youtube.com/watch?v=UYGU7mTwsZc

At 5:13 you can see that the balancer moves to the right and the guys telling that this is advanced timing... and it does the SAME on my engine....but on my metal plate if it moves to the right towards the word AFTER i assume it is retarding timing and not advancing.....?

Further in this video they are doing it on a small block where dist rotates clockwise.... Because of this it is vice versa comparing to my engine? or does it not matter if dist runs CW or CCW and the balancer mark always moves to the right if engine is revved up?

I am confused ....

[rollo1504]

... I have found in another thread a picture from the web....

Looks like I really understood it wrong....

So I was searching the internet and could find a DIY timing tape printout.... I will measure the diameter create a tape on my own and put it on with marks from 0 - 60 on my engine as it is shown on the pic and then I will try again..

So If I put the tape then on the balancer the 0 of my timing tape is where the mark on the balancer is correct?

What do you think guys?

Then I will hopefully be fine concerning the timing....

[justcruisin]

Your clip shows a move to the left as RPM ramps up as it should be.

I think there is some confusion over the explanation given and your interpretation of it.

If you are going to put some timing tape on your balancer it is a good idea to verify TDC by using a piston stop, (can give a "how to" if you want or simply take your line on your balancer as correct and place the 0 mark on your tape at that point.