Timing + Ignition advance

[DAA]

Hi all..
After my carb revision i need to check my ignition time, i will use a multimeter (dwell test ) to read the actually values, but due to my first time doing this i have some doubts..

How is the position here?



After found this position, i will find that 1st cylinder on top, right? I don't know the term in English

Can some one share the reference values of the ignition for the 956cc motor?

Thanks everyone

 

[angel]

The timing scale is the set of lines visible under the bolt head on your photo, not the three dots at the front of the aperture.
There is a notch on the flywheel, when it's opposite the far left line (as viewed on your photo), engine is at top dead centre. The rightmost line corresponds to 6deg BTDC, this is the correct ignition timing at idle with vacuum unit disconnected.

 

[orsome]

Hi,

I wonder what would it be with electric ingnition system without vacuum system at all. I did check it once with strobosscope butcould it have been even 18degrees? Its 845cm3 with ducellier distributor 1977.It takes incredible high revs but haven't measured the rpm's

 

[DAA]

@angel thanks a lot of your comment.

I will try do the dwell test and check the actual measurement.

Can you please explain, why this action must be done with vacuum unit disconnected?

 

[DAA]

Hi,

I wonder what would it be with electric ingnition system without vacuum system at all. I did check it once with strobosscope butcould it have been even 18degrees? Its 845cm3 with ducellier distributor 1977.It takes incredible high revs but haven't measured the rpm's

I don't know the best way tho measure the rpm's. My multimeter measure but i only use to Check the idle rpm

 

[angel]

@angel thanks a lot of your comment.

I will try do the dwell test and check the actual measurement.

Can you please explain, why this action must be done with vacuum unit disconnected?

Because you are setting the basic ignition timing. This vacuum advance unit adds ignition advance when manifold vacuum is high - that is, at idle and on light load. If you leave it connected, you would measure around 15 degrees of total advance at idle, so you would have to retard basic timing too much in order to reach the 6deg. figure.
Note that we are talking about setting ignition timing with a stroboscopic light and engine running. If you are doing it statically, there is no need to disconnect the vacuum advance unit.

 

[DAA]

Because you are setting the basic ignition timing. This vacuum advance unit adds ignition advance when manifold vacuum is high - that is, at idle and on light load. If you leave it connected, you would measure around 15 degrees of total advance at idle, so you would have to retard basic timing too much in order to reach the 6deg. figure.
Note that we are talking about setting ignition timing with a stroboscopic light and engine running. If you are doing it statically, there is no need to disconnect the vacuum advance unit.

Ok, now makes me sense all of I had read.

What you recommend? running or static adjust?



Before doing any modification of the actual settings I will measure the dwell angle with my multimeter, with the engine running and with normal motor temperature. This value reference are from 54 to 60, right?

 

[angel]

You are right about dwell angle setting.
I prefer to set timing with engine running.

 

[DAA]

Thanks a lot @angel. I will share the results after.

 

[André4Renaults]

Ok, now makes me sense all of I had read.

What you recommend? running or static adjust?



Before doing any modification of the actual settings I will measure the dwell angle with my multimeter, with the engine running and with normal motor temperature. This value reference are from 54 to 60, right?

My advice, based on many years of setting ignition timing is to set it with the engine running (in English this is called "dynamic" setting) as this means you can "feel" the difference!
The dwell angle is critical and you should set this up first, with a good quality meter. As the setting for a Renault 4 is between 54-60 degrees, aim for 57. Once you've set this properly (which can take some time!) Only then adjust the timing, because re-setting the dwell angle will have upset the timing. Believe me, if it's done properly the increase in performance, even in the most modest cars, is well worth the effort!

 

[DAA]

My advice, based on many years of setting ignition timing is to set it with the engine running (in English this is called "dynamic" setting) as this means you can "feel" the difference!
The dwell angle is critical and you should set this up first, with a good quality meter. As the setting for a Renault 4 is between 54-60 degrees, aim for 57. Once you've set this properly (which can take some time!) Only then adjust the timing, because re-setting the dwell angle will have upset the timing. Believe me, if it's done properly the increase in performance, even in the most modest cars, is well worth the effort!

Thanks a lot for all advices!!

 

[DAA]

Today I prepare everything to do mesurmers..



Wheel in the air.. To move the flywheel



6º marked


"Rotor" in direction to the spark cable of 1st cylinder.. The motor seems to be on good advance value.




Dwell test..more Than one.. Different values, or I don't know do the test, bad multimeter measure or any problem, let's check..




I don't know name of this in English... It's broken, probably original


And let's take some cleanings..




Now I will request new parts.. What is your opinion to change for electronic?

How it's possible the car running well, it takes 110km/h.. 4L is a big machine eheh

 

[angel]

(in English this is called "dynamic" setting)

"Dynamic" is, in fact, a Greek word

 

[DAA]

Today I had a little time to start install the new parts..

Timming setting, on the 2nd mark, gap of the platinum on 0.40mm, new paper junction.







Tomorrow I will try start the engine. After this measure I can notice I had the ignition to advanced.

 

[DAA]

Today.. First start was good, without problems..

During the first run, when I slow down, the 4L made a enormous misfire, I set a poor the mixture on the carburetor, and I have more smooth ride, good performance, good idle without "brakes". But.. After a stop for lunchit is was very difficult to but the 4L back working again.. Any tip?? After start again, it ran without problems.

After the misfire I did a new platinum set..

A bad dweel angle can do this on start?

Are this the right position to set the dwell? This is the position on the ignition set mark on the clutch l.

 

[André4Renaults]

When the engine is running and warmed up, what reading do you have for the dwell angle? I should be between 54 and 61 degrees, so 57 would be perfect. You need to ensure this is set correctly first.

 

[DAA]

When the engine is running and warmed up, what reading do you have for the dwell angle? I should be between 54 and 61 degrees, so 57 would be perfect. You need to ensure this is set correctly first.

The value is 37 degrees, before had 27degress, when I have the enormous misfires. But I'm setting (0.40mm)before the lobe of the distributor, with the engine setting to the middle mark on the clutch. Is this correct? Or the right is do the setting in top of the lobe with the gap totally open?

 

[André4Renaults]

Your dwell angle of 37 degrees is lower than the 57 degrees it should be, so you need to lower the points gap a fraction more. Remember, to increase the dwell angle you need to decrease the points gap, but only a very small amount. You need to measure the gap with the points at their most open, which is when the lobe is at its highest point. Looking at the picture above I don't think your points are quite fully open yet. Don't worry yourself with the markings on the clutch at the moment-let's get the points gap set accurately first!

 

[DAA]

Your dwell angle of 37 degrees is lower than the 57 degrees it should be, so you need to lower the points gap a fraction more. Remember, to increase the dwell angle you need to decrease the points gap, but only a very small amount. You need to measure the gap with the points at their most open, which is when the lobe is at its highest point. Looking at the picture above I don't think your points are quite fully open yet. Don't worry yourself with the markings on the clutch at the moment-let's get the points gap set accurately first!

So is that my mistake, I am setting before the highest point of the lobe. I will setting again. Thanks a lot!! I will share the results

 

[DAA]

Dwell set at 56degress..but I loss the smooth drive and some exitacion at low rpm.. And the exhaust noise is very powerful..

Any tip?

Renault 4L

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