Dizzy with Choices

I dropped off my Mallory Unilite with one of the rare sort that actually has a machine to spin and read curves (he collects these machines). I just wanted the curve mapped to see what advance was built-in etc…

That was some months ago and every time I call there is a problem with this or that. Mainly, and I will admit to being the culprit, the housing and spindle are not pretty, with dents and dings from manhandling it into place but it was working when I gave it it to him and now I am not sure. I got tired of hearing about my past indiscretions so I bit the bullet and bought, on-line, a new 123 unit (not the “Tune” version with the computer connection). It is a version that has vacuum advance capacity and my original, and the subsequent Unilite was mechanical only- do I just plug the vac port on the new dizzy or find a way to hookup to port vacuum where there has never been (I have the original Strombergs). I draw vacuum for the vacuum reservoir off the intake manifold and there is a small short vac line for the bypass valve on the front carb.

Thanks,

Huff
69 2+2

That’s the version of the 123 that I’ve got, Huff. I think that you will have to connect up the vacuum advance.

Very easy to create ported vacuum on a stromberg.

The carbs have a hole where a fitting will go. (Rear carb shown here, you will want your fitting in the front carb.)

Drill a small hole through the bottom of the factory hole to penetrate the cast aluminum of the carb body and provide a passageway from the carb throat to the fitting you are going to install. Make sure you angle the drill parallel to factory hole so the other end winds up in front of (or before) the butterfly. See where the pencil is pointing.

Thread factory hole and install appropriate sized fitting.

I like it!! As the carbs are off, as is, I was planning on freshening up the diaphragms, inspecting, cleaning and the like and this is a great add to that!

I applaud the use of the carpenter’s pencil sharpener as a prop. Is the sort of thing I do, too.

Great relaying of info for the task- you must be (or were) a teacher.

Thanks much.

Huff

Thanks and Why yes, yes I was.

Is your car a 4.2litre? Just out of interest which advance curve are you planning on using?

Hi Nigel,

It is a 4.2 and from what I have gleaned in my research, I will start with curve “7” or “D” and see what happens.

There is quite a “learning curve” as well, it seems.

Huff
69 2+2

Hi Huff
You’re right! I can never find any data in the booklet that comes with the 123 that relates to anything on Jaguar Lucas distributors. I e mailed them and even they couldn’t tell me the appropriate choice!
Best Regards
Nigel

Hi Huff
How did you discover which ones to try? Purely on advance curve? Or did you find it out on the internet or something?
In my experience the numbers on the distributors never bear any resemblance to the numbers they quote in their booklet for Jaguar distributors!
Best Regards
Nigel

I went with the default curve. I don’t remember what it is but it seems like it was “0” and it ran so well that I never changed it. I’ll check when I get home tonight just what the setting is that I used.

Hi Nigel,

I have yet to even receive the dizzy, but in the meantime I have done some research so as to have a starting point. A lot of these have been installed in Jags and specifically E-Types, whereas there is a model of the 123 that has “Jag” in the model number.

I won’t really know much more about the curve(s) for a few months until after the engine is back in and will try to update, after. Much seems dependent upon the engine build, i.e…stock, compression change, head/block milling, carbs and other “tuning” efficiency or discrepancies to each case.

Thanks,

Huff

Here is the generic 6RV curve:
http://www.123ignition.nl/product.phtml?id=32

And the Jag 6RV:
http://www.123ignition.nl/product.phtml?id=35

I prefer the /tune version. On the one hand you can adjust the curve (both advance and vacuum), on the other hand you can set two curves (Track, road). You can also set a rev limit with the /tune.

If you can, change the order to the /tune version.

Hi Andrew,

Was already shipped. Durn. I hate casually returning parts, as returns must frustrate merchants, but I have inquired if the have the Tune version, just in case I can do a swap for a few more $

Huff

I assume without the ‘10 degree vac assisted advance’ pipe connected there would be pinging ?
Would ‘123’ work with 8:1 pistons instead of usual 9:1 ?

thanks,
Patrick
'66 FHC

Hi Patrick,

My original didn’t have a vac setup, so, supposedly, the vac add is a perk, of sorts. I am over-simplifying but I don’t see any reason why it shouldn’t make just about any engine run better than the stock unit, if, for nothing else, accuracy of the spark timing. The adjust-ability could dial in for conditions such as age, condition-of-tune, fuel quality, even driving habits.

I will post more once I have it running (some months).

Huff
69 2+2

Huff, thanks for your reply: Is this Ebay item the E-type tuneable 123-Ignition version ?

http://www.ebay.com/itm/JAGUAR-E-TYPE-MKII-S-TYPE-123-IGNITION-ELECTRONIC-DISTRIBUTOR-123IGN/282581282457?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

I assume that if 123-tuneable, then E-owner could fuel up with say, 93 pump gas and adjust-tune till owner hears pinging, then back off the 123-tuning degree setting to where no pinging occurs on same tank of 93 oct fuel ? Am I correct that some 123-Etype dists are not tuneable ?

Patrick
'66 FHC

The 123’s are all “tune-able” via a dial wheel on the body BUT it is not the super-groovy “Tune” version that has the port for plugging in a laptop, so you can adjust in real time, which is approx $100 more and a special order thru this vendor.

I wanted the Tune version but was too quick on the draw to purchase. If you buy the Tune version I will pay the difference and swap you for the regular vac advance version I just received (you probably have a vac port already setup in your car if it is the 66 FHC) if you really don’t want the Tune version, but if it is a hassle I can live with what I have, readily.

I don’t know much about the settings and capabilities, just yet, but in theory, you are correct about reducing pinging.

Good luck,

Huff
69 2+2

Hi Huff,

Is that Ebay link I provided the “TUNE” Version that your seeking ?

Thanks,
Patrick ( I’m tad dense )
'66 FHC

No, you are not correct. The 123 Ignition dizzy comes in two models, Standard and Tune. One of the big advantages of the 123 is that it IS tunable by the user for several different advance curves. The standard model, which I have, has 16 different curves; I don’t know how many the 123 Tune model has. The advantage of the Tune model is that it can be hooked up to a laptop via USB cable and then adjusted while the car is being driven (obviously, by another person) to achieve the optimum curve. To find the optimum with the Standard model, the distributor has to be removed and the adjustment screw accessed at the bottom of the lower housing and then reinstalled for a test drive. I went with the default curve(“0” as I recall) and the car starts and runs so well, that I just left it there.