The 'E' Type Forum

I am running on the original opus ignition system,which i would like to up grade .
Any suggestions what to use?

A 123 tune+ distributor.

http://www.123ignition.nl/product.phtml?id=195

It will bring your sparks back in line and make them 6 times bigger.

As long as your distributor drive is not worn.

will this do the v12?

Hi Dave
apparently 123 are in the process of developing a V12 distributor. I've fitted the SNG Barratt a few times with good results. Not cheap, but was is for a V12 E type!

Sorry for refering to you as Dave! its terrible getting old!

Guys...put your names in the signature line with your car model.....its more friendly. ...Steve

I put the SNG Barratt system in my 73 V12 and it made a significant difference. The car starts quick and runs significantly smoother. Not outrageous cost wise (I guess that's relative), after the core charge was returned it was about $650 for everything. It took me roughly 6 hours to get it all put together, re-timed and working right. I messed up installing the distributor the first time (off by a cog) but the instructions that come with it are very good.

Steve

In the moment 123 can not offer a ignition system for the V12 motor. I have heard, that the owner has too less time, to develop a system for the V12.
A cheap way to cure ignition problems of the original Opus system, is to mount a used ignition system from a XJ12 with HE-motor or XJS with HE-motor. I have this in my car. All working well.
Regards Wolfgang Gatza

I also fitted the Lucas ignition system from an HE XJS V12 to the car I've rebuilt and it runs perfectly all the way to 6000rpm.

My own car is fitted with a Lumenition system and also works perfectly to 6000rpm.

The challenge with a V12 / distributor is that very little time is available after 5000rpm between sparks to charge the coil - hence the double coil setup in the HE system.

In any event, PLEASE fit a vacuum ADVANCE diaphragm to the car. It makes a HUGE difference in the engine's efficiency AT PART THROTTLE.

I've got the Reopus ingition on mine with the standard dizzy. Works very well and not had any problems. Easy to fit too if you can use a soldering iron.

Hi guys
If you check out the reopus website you'll find that it's no longer available.
I fitted the SNG Barratt replacement HE system, and find it excellent. It does give you a rebuilt dizzy as well, which as we all know generally benefits from a rebuild.
This kit is still has a retard vacuum capsule fitted, so Jagwits suggestion to fit a vacuum advance capsule is the right way to go.

Regards

I fitted the SNG to my S3 last fall. She was extremely hard to hot start prior to the new dizzy install. The SNG helped with the problem. After rebuilding the carbs this spring she runs great. Fairly easy install, although it was tough to see the wire colors. I was replacing a cobbled together LED system where the disc was pop riveted onto the drive. Tach wire was the toughest one to figure out.

Started first time off, the timing was close enough to get her to start fight up.

Good luck.

Dennis

jagwit wrote:The challenge with a V12 / distributor is that very little time is available after 5000rpm between sparks to charge the coil - hence the double coil setup in the HE system.

I've read this before, but I'm curious why systems like the SNG system do not use dual coils and I've only heard positive things about the SNG system. Any insight you can provide?

lundabo wrote: I'm curious why systems like the SNG system do not use dual coils and I've only heard positive things about the SNG system. Any insight you can provide?

When you run a V12 at 6000rpm with a single coil, you need to produce 600 sparks per second or one spark every 0.00167s (1.67mS). That is VERY little time to charge (and discharge) a conventional coil. A typical coil requires about 2mS to charge.

A coil is actually two electronic devices in one: It is an inductor(the coil primary circuit) and it is a transformer(primary and secondary together). So, either you have to use a dual coil setup like Lucas did, or you have to use a coil with a VERY low primary impedance and resistance - IF you rely on the coil primary circuit for generating the +-300V primary voltage spike. But then it becomes a challenge to generate sufficient Magnetic flux on the coil primary to convert into spark and still have sufficient energy in the spark. Perhaps there are modern coils available that meet this requirement???

Another method of generating spark is using the capacitive discharge method where you charge a capacitor to a very high voltage which CAN be done very quickly with modern electronics (now you are NOT relying on the coil primary windings to do so) and you then discharge this capacitor onto the coil, effectively using only the transformer function of the coil to generate the >30kV secondary voltage.

The MSD6A system is an example that I know rely on the capacitive discharge method. In fact, it can charge its discharge capacitor so fast that it procudes 3 sparks per combustion stroke on a V8 at lowish RPMS, dropping to two higher up and then eventually doing 1 per combustion at the top end.

I had a MSD6A on my v12 XJS before I converted to my dual EDIS-6 setup and IIRC it was generating three sparks per combustion stroke till about 1300rpm, dropping to two sparks per combustion stroke till just above 2000rpm and then to 1.

What I don't like about the SNG system is that you have to relinquish your existing stuff including distributor. (Desperate measures at desperate times I suppose)
I some years back managed to get a Crane XR 700 if I remember rightly to work great with some fettling. You discard the OPUS and put in an optical trigger/disc into the distributer and a replacement black box.
I did eventually use an oil filled Crane coil but it work well with the Lucas DLB198 coil as used in Morris Marina (compatible to V12E!)
Not sure if still around but I think so on ebay.com. USA

Hello all, happy new year. I’m in the middle of swapping my 45 y/o Opus ignition system for a 30 y/o CEI system (ex ’86 Sovereign V12). Mainly to see what if any efficiency gains can be realised by adding vacuum advance?
I’ve wired it up like this:
https://1drv.ms/b/s!AiSPBKa26IcchJZLeWcVblhg--x5oQ
Distributors were just a straight swap and the CE ignition amplifier fits perfectly in place of the Opus ballast resistor. The coils I’ve temporarily fitted in place of the inlet air trumpets, this was to avoid making brackets until I figured out what works. Turned out not so labour-saving, coil lead wasn’t long enough, I had to make a longer one.
Carbs are very noisy without the trumpets.
The E-type’s original (Opus) distributor does not have vacuum advance. It used vacuum to retard the ignition when the engine was idling. This was disconnected on my car.
The centrifugal advance curve provided by the CEI distributor seems to be the same as the original Opus distributor. With the CEI distributor set to 12 deg BTDC at idle I get 25 deg BTDC at 1900 rpm and 32 deg BTDC at 3500 rpm, which is within-spec for the E-type/Opus (workshop manual 86.35.00/3).
The CEI distributor’s vacuum advance module is not yet connected, its broken, I’ve ordered a new one. So far, I have travelled >1000 km with the CEI system without vacuum advance. Performance and efficiency seems the same as with the Opus. The CEI amplifier gets quite hot. Do we know what temperature Is too much?
Where to take the vacuum (for advance) from? The tapping must provide: very little to no vacuum at idle, otherwise stable manifold vacuum. The E-type’s existing TB/D tapping (for Opus retard unit) is no good, it provides the opposite: TB/D (my definition) = throttle bottom edge tapping on downstream side. When the throttle plates are closed (idling) the tapping is just downstream (manifold side) of the throttle plate and therefore provides vacuum. As the bottom of the throttle plate opens inward the tapping becomes effectively upstream of the throttle plate, so off-idle it provides virtually NO vacuum.
What I need is a TT/U = throttle top edge tapping on upstream side. When the throttle plates are closed (idling) the tapping is just upstream (air-cleaner side) of the throttle plate and therefore provides no vacuum. As the top of the throttle plate opens outward the tapping becomes effectively downstream of the throttle plate, so off-idle it provides manifold vacuum. However, the E-type does not have a TT/U tapping and I am reluctant to drill one, while this is just an experiment …
Instead I am planning to use vacuum from an existing deep manifold tapping (i.e. one that is well away/downstream of throttle plates) and to use a modified dump valve to vent this supply whenever the car is idling. Here is a pic of the inside of the dump valve, Jaguar P/N EAC4070. Prise open and snap shut, hard to see why they are so expensive …
https://1drv.ms/i/s!AiSPBKa26IcchJY39O-qYC__PzoqBA
Normally the dump valve is held closed by a control vacuum, the valve opens when the control vacuum is lost. I need the opposite, a valve that is held open by a control vacuum, that closes when the control vacuum is lost. Then I will be able to use the E-type’s existing TB/D tapping for the control vacuum, to vent the vacuum advance line whenever the car is idling. To achieve this, I propose to modify the dump valve as follows:
https://1drv.ms/b/s!AiSPBKa26IcchJgkJbiWfHN7f7NLHA
Hopefully it will then be just a matter of altering the static timing and the (adjustable) vacuum advance module to whatever is optimum?
Thanks, and regards,
ColinL

Your assessment is entirely right.

If you look at the later emissions cars, the necessary tapping you seek (for a ported vacuum) already exists on cars which had the EGR pipes fitted. That'd provide no signal at idle, a strong signal at moderate throttle openings tailing off to zero again as throttle is progressively opened. It means you could dispense with the dump valve. You can find details in the tan coloured US Owners Manuals.

kind regards
Marek

MarekH wrote: ↑

Sat Jan 06, 2018 12:03 pm

That'd provide no signal at idle

Marek, do you have theory as to WHY one would WANT to have no signal at idle? My question is genuine as I'm still trying to understand why having ported vacuum appears to be such a big deal. (Given that my E seems perfectly happy on permanent vacuum)

Hi Philip
Isn’t the issue that, in your case, with vacuum still being provided to the advance capsule at idle, then extra advance will be provided at idle, which I believe is undesirable.
Well jaguar thought so which is why they set up the system to avoid this.
Cheers

Exactly how much more advance do want to run at idle and why? I presume you'd end up removing static advance (from the entire rev range) if you were to boost it via vacuum too much at idle as the car presumably already has the advance it wants at very low rpm including idle. The objective, if you look at the little advance diagram on the Bywater website, would be to increase advance at low rpm below the peak torque rpm.




kind regards
Marek