123 Ignition Electronic Distributor

[David Hill]

Does anybody have any experience of fitting a 123 ignition distributor to a TR5/6?

I have been advised to use either B or C curve but I wondered if any other members have any suggestions?

[harlequin]

I have a 123 with the 16 preset curves and am very happy with it, however most now recomend the programmable type as none the curves on the old switch type will be exact right. So if you are about to purchase one go for the newer type.

If you already have the preset type most people recommend curve B for injected cars and curve 6 for carbs, this is probably a good starting point.

My 123 is really for a Jaguar so the preset curves are different, because of this I had to go on trial and error to find the best setting

George 

[David Hill]

Thank you for that. Yes I bought mine about two years ago before I really needed it so it is the old type and not programmable unfortunately.  I see the new one can be programmed from a downloaded app on the phone!

I will try curve B and see how it goes.  I assume basic timing is still set at 11 degs BTDC?

[Ian Vincent]

FWIW, to make it easier to compare curves, I plotted the factory curve on an excel spreadsheet graph along with the curves from the 123 manual and it was fairly straightforward to see which would be most suitable. Having said that, the 123 I was using was a S/H bargain and I subsequently decided to revert to a distributor (rebuilt by the Distributor Doctor) and a Pertronix set up. 

Rgds Ian

PS Mine is a 4 pot TR3a. 

Edited November 17, 2023 by Ian Vincent

[David Hill]

How do you find the DD distributor with the Pertronix?

I am annoyed that I really need the latest type which could be programmed correctly.

Regards

David

 

[harlequin]

2 hours ago, David Hill said:

 

I will try curve B and see how it goes.  I assume basic timing is still set at 11 degs BTDC?

I have used the 123 recomended 10° static timing which works well with curve 2 on my 123/JAG-6-R-V this gives 12° at 1200 rpm 21.8 at 2000 rpm and 34° all in at 3000 rpm,  any vacuum advance is over and above these figures. 

I realise 34° is a little bit above the 30 to 32 degrees recommended for the 6 cylinder Triumph engine but so far I have not experienced any pinking.

You may find that the timing marks will jump about a bit under a strobe with the 123, I was a bit confused by this but it turned out that its a feature where the 123 compensates for the differences between cylinders to give a smooth tick over. I eliminated a lot of this by setting the tappets very carefully.

George 

 

[Ian Vincent]

41 minutes ago, David Hill said:

How do you find the DD distributor with the Pertronix?

I am annoyed that I really need the latest type which could be programmed correctly.

Regards

David

 

Smooth as silk.  I gave Martin (DD) the details of my engine and he set the distributor up with his recomended curve and provided a set of test results when he returned it to me.  I just fitted it back on the engine and it has been good as gold ever since.  I have the ignition advanced until it starts to pink and then backed it off a little.  AFAICR it is currently at about 12 deg advance at idle with the vacuum connected.

Rgds Ian

[Lebro]

+1  same experience for me

Bob

[BlueTR3A-5EKT]

On 11/17/2023 at 1:14 PM, David Hill said:

How do you find the DD distributor with the Pertronix?

I am annoyed that I really need the latest type which could be programmed correctly.

Regards

David

 

Just fitting the Pertronix to a worn distributor gave a noticeable improvement to tickover and pick up.  The rebuilt unit from DD with it fitted was a step better.