The 'E' Type Forum

I have just fitted a new 123 Distributor to my series 2 OTS having rebuilt the entire car. and not run the engine, Today I switched on the ignition I immediately got a full reading on the rev counter i.e.6000 rpm. I then disconnected the feed to the rev counter just leaving the ignition loop and tried again, this time the needle stayed at zero. I then turned the key further WOW! it started straight away it is so smooth it sounds like a sewing machine. sorry I digress. Anyone got any thoughts on what is wrong with the rev counter.
A happy Steve in sunny Scarborough.

I am afraid that these impulse tachos often do not work with electronic ignition . I think that there are various modules available which will convert them to the later type which will work. Those who have put pertronix on will probably be able to help

Steve

They are a straight bolt on job on the Series 1 but do need a gizmo to work with the Series 2 tacho.

I don't have the details to hand but I think you will find the subject covered on their website and almost certainly on Jag Lovers.

It's amazing just how rough your engine was before you knew better isn't it?

Andy

From a fellow user who posted on the 123 forum (I accept no responsibility!)
Hello

For who is interested, herewith my positive experience with a 123 ignition installed on my Jag
E-type series II 1969, 4.2 litre.

New sparkplugs, ignition cables, contact point and distributor cap and rotor were already installed, but the engine wasn't running stable since worn out of the distributor shaft and bad vacuum advantage operation.
On recommendation of a motor rebuilder I installed a 123 ignition.

Wiring the unit as per added installation manual gives problems with my tacho.
On the 4.2 litre engines the coil is powered via the tacho. Connecting the red wire of the 123 ignition directly on the + terminal of the coil gives wrong indication on the tacho.( always 6000 rpm, with not running engine)
On the 3.8 liter engines is a separate counter installed on one of the camshafts
No problems for those motors to connect the red wire to the + terminal.

A separate + wire to the 123 ignition, The + terminal of the coil connected to the tacho and the -
terminal of the coil connected to the black wire of the 123 ignition solved this problem.

Static adjustment of 8 deg. since my car is running on lead free gasoline. With the strobe I fine tuned to 10 deg at 1000 rpm.
Curve switch setting at 0

The results until now are very positive :
-The car is starting much better
-The motor is running more smoothly and stable at 700 rpm .....
-Very Good acceleration
-Stable running at constant speed.


I don't know if the 123 ignition gives more power than a standard Lucas.
Are the positive results only due to the 123 ignition? .
Maybe a new Lucas distributor gives the same results.
For sure this works and adjustments every 2000 km are not more needed.

So this was my story

Success

Many thanks Andy, I put a separate positive supply to the distibutor and it works a treat.
Steve.

Hi Steve
I presume you have bought the 123\JAG-6-R-V model, did you go for the one that has the vacuum advance connection?
John H

Hello John.
No I did not use the Jag 123, on the advice of SC who supplied the distributor. as my engine is standard then the GB-6-R-V with vac is the one for me.Apparently the manufacturers made the Jag version for modified XK engines.

Steve.

Steve: thanks for info, however did you set your static timing point at TDC or 10 degrees BTDC and what curve setting have you used?

Andy: Out of interest which 123 model did you use, also can you remember your curve setting and initial set up re: static timing?

Thanks
John H

Hello John.
I set my static timing as per instructions at TDC. and a curve setting number 6. The engine fired up immediately and even after a full rebuild it settled down to a very smooth tickover. I then did a strobe test and at 1000rpm I got a reading of 10 degrees BTDC. I am still finishing the car and as yet have not had a drive.
Steve.

John

I'm very sorry for my tardy reply but I've be rather tied up with that annoying work stuff for a few weeks so I've been using the car rather than tinkering and posting.

I have the Jag version and I'm on curve 7 and 10 BTDC static but I do use super unleaded and an additive that claims to boost octane (Valvemaster +).

If you are running unleaded I'd pick a curve that is a degree or so behind that.

If you don't have one already I think ?20 is well spent on a Lucus sports coil.

Andy

Thanks for info and advice.

John H

andyp wrote: If you don't have one already I think ?20 is well spent on a Lucus sports coil.

Andy

Agreed on the coil. I have been trying the Lucas Sport and Bosch 'Blue' coils both with good effect. The Bosch seems to be favoured by people like VSE but I cannot tell the difference between them other than the Lucas is a very pretty gold colour and the Bosh Blue is, err, blue. I can also recommend the spiral wound Moroso ignition leads which Rob Beere sells complete with C-Type separator.

Andy
Is your 4.2 engine modified/uprated or standard? it seems to me comparing the 123/JAG versions lower numbered curves are similar to the "123/GB- straight Lucas swap" model's higher numbered curves.
John H

Hi all,

can I ask a "dummy" question ? How can you tell/measure if your electronic ignition (be it pertronix or 123 or another) works well ?

Many thx and sorry if this is an obvious question

cheers
Erik

Delayed again.

John, my engine is standard on high octane fuel.

Erik, the 123 has an LED that comes on to allow you to set the static timing. Those crafty dutchmen think of everything.

Andy

Andy: Thanks for coming back, my 4.2 is standard as well and I've opted for the Jag specific model, noting some curves overlap anyway.

I haven't got it yet so last week in preparation decided to check the timing figures on the existing Lucas distributor before I change it, interestingly my current reading for 2,000 rpm gave me 28 degrees BTDC !!!! and at 3000 rpm about 32 degrees. The engine doesn't seem to suffer from pinking on high octane fuel however from now on passing 2000 rpm I ought to take it easy until I get the new toy.
John H

John

I think 34 @ 3000rpm is about as far as you want to go but the nice thing with the 123 is that you can start with something similar to your current set up and then notch things up until it gets upset.

Unfortunately you have to pull the unit to make changes which is my only real complaint but I suppose it does stop people changing curves with the unit turned on or running which would probably do it no good at all.

Andy

I have a 123/Tune to fit to my S2, I note the comments about not powering + from the coil, where should I run a supply from?

Ian

Chris

In answer to your post-The Petronix module fits the S1 distributor(DMBZ6) without any mods to the Tacho supply. I was unaware of any issues with this until I read this thread. You live and learn!

Alan

Alan : the series 1 tacho ( camshaft AC generator driven ) is wholly different from the S2 tacho which is ignition impulse driven . There are no problems, irrespective of ignition system, with camshaft driven tachos

Having resurrected this Lazarus thread, can anyone suggest where I should take the + feed to the 123 from, is C2 on the fan relay a good choice?

Thanks

Ian