Distributor syncrograph

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Distributor syncrograph

Postby DebbieSidera » Wed Oct 23, 2013 5:44 am

Hi,

I would like to know if anybody is using the Pico software to 'emulate' a distributor syncrograph machine. I mean... my idea is to see a better signal of the points. I have been using an old SUN machine for years... but to get an accurate result you should have to test the distributor several times on the car and sometimes this it could represents lots of time consuming.

Thanks.
Debbie.
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Re: Distributor syncrograph

Postby Steve Smith » Thu Oct 24, 2013 10:03 pm

Hi Debbie and thank you for your post. To be perfectly honest I had to Google Syncrograph and can now see how this device determines the stability of a conventional distributor at various speeds to conclude good even dwell with mechanical and vacuum advance. In answer to your question I would like you to refer to a fantastic video tutorial on our website https://www.picoauto.com/video/volvo-problem-child.html which utilises the WPS500 pressure transducer to determine the TDC of number 1 cylinder. Once this is established, with a trigger on No.1 ignition lead the ignition timing can be calculated in relation to TDC. The video from Autonerdz explains this very well using 2 different techniques.

My line of thinking is that once you can determine the TDC of No1 cylinder and the time frame between each ignition of No1 cylinder, you can then calculate the position of the remaining cylinders using the phase markers available in the Pico beta software (180 degree intervals between No1 cylinder firing events on a 4 cylinder engine). With this in mind you can monitor the primary ignition voltage and current then plot them exactly like the video against the phase markers (TDC) You can then calculate the ignition timing for each cylinder at idle, with vacuum applied to the vacuum advance unit, and at high engine speeds to determine the integrity of the mechanical advance device.

Because you can monitor the primary voltage and current you can also measure the Dwell period at all engine speeds to confirm no wear in the contact breaker points "Heel", rotor cam, or timing gears.

I hope this helps, take care.......Steve
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Re: Distributor syncrograph

Postby DebbieSidera » Tue Nov 12, 2013 7:44 am

Hi Steve, Sorry about the delay on my answer. Thanks for this video. It was great!
I'm personally using the Syncrograph (or we just call it, distributor machine) to synchronize the breaker points. Normally in old Ferrari and Lamborghini engines you have two distributors with two breaker points in each one or just a big distributor with 4 breaker points to manage the 12 cylinders. Basically the degree wheel of this machine is telling you if you have a symmetric angles of the breaker points during their dwell but the accuracy is too poor.
As i have been checking with the Pico. The "waves of the signal" of a tired and old breaker points are very curved and very difficult to measure. Normally I file them flat nice and clean and then "waves of the signal" become almost square and very easy to measure. Connecting the Channel A,B,C and D to the breaker points the signals will appear like a cascade on the screen after one complete revolution of the distributor cam. The time of a revolution should be the result of 4 symmetric waves, so the time measures the angle.
The centrifugal force makes expand the spring and the weights to advance the timing if you increase the RPM. Is always a challenge to set up a good ignition to run with good idle and a high RPM engine.
I'll keep practicing!
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Re: Distributor syncrograph

Postby DebbieSidera » Fri Jan 31, 2014 7:16 am

Some of the Magneti Marelli used in Lamborghini.
The first is is a V12 with one distributor with four breaker points.
The second a V12 with two distributors with two breaker points
Attachments
IMG_00002002.jpg
Lambo Miura. 4 breaker points
IMG_00001983.jpg
Lambo Miura. 2 breaker points.
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Re: Distributor syncrograph

Postby DebbieSidera » Fri Jan 31, 2014 7:23 am

Here Some of the test.
To compare the dwell is so much easy with an oscilloscope. :D
Attachments
IMG_00001981.jpg
IMG_00001980.jpg
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Re: Distributor syncrograph

Postby DebbieSidera » Tue Sep 16, 2014 2:06 am

I thought that I should share this picture. Jaguar XJ12 - Distributor with injection and ignition.
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XJ12_Distributor_Draw.jpg
Draft
IMG_00005145.jpg
Set up
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