I must confess near-total ignorance on the pros and cons of each ignition system upgrade. Can someone help an electric-deficient Jag Lover the pros/cons and/or differences between:
EDIS
There is not a company that provides all the bits in a bundle for the V12 so would require sourcing the various bits from different vendors/breaker yards and assembling with some fabrication; using my existing dizzy with a replacement vac adv (avail from SNG Barratt for $122)
The goal of using one of these systems:
*removes the unreliable and heat-soak prone original system. I upgraded years ago by putting the amplifier on the rail below the header tank vice the center of the Vee. Small upgrade
*The original system (compared to all/most(?) of the above options) takes longer to crank / start whether the engine is hot or cold, results in an idle that is not as steady, gets a little dicey at upper RPMs, and uses more fuel. (If fuel economy is my goal I would go EFI (but I value originality) and certainly would have traded the Jag in for Prius long ago.) So I think I can gain easier starts, smoother operation, higher/easier revving engine, better mileage.
If possible, please address these criteria in your reply:
EDIS does away with your distributor altogether. I have this on my 3.8 Mk2 engine which is currently running on a test stand. Won’t be in the car for a while as I finish the rest of the restoration. It required a bit of planning and fabrication but so far appears to be flawless. Advance can be controlled through a laptop and still has a vacuum advance albeit electronically actuated. For the six cylinder XK motors there’s a fair amount of documentation online for the EDIS conversion. Not sure about the 12. I never came across a full kit so ended up sourcing parts from various places and having a local machine shop machine the trigger wheel to fit on the backside of my crank pulley.
On my motor I mounted the coil pack where the original distributor would go. Conversion is fully reversible.
I can’t imagine anyone who really understands all those systems NOT telling you that EDIS is, by FAR, the best of the bunch. But, it is also the most complex to retrofit. EDIS completely eliminates the distributor. ALL spark timing is defined by a crank-mounted toothed wheel, a position sensor, and a micro-processor. Load sensing can be performed by either a throttle position sensor, or (better) a manifold absolute pressure sensor. There is one coil for each pair of cylinders, so six coils. No distributor, no mechanical advance hardware, and no vacuum advance hardware. Spark timing is defined using a GUI application running on a laptop, by filling in a 2D “map” of RPM vs Engine Load. Most people who bought my 6-cylinder EDIS kits reported HUGE improvements in starting, idle quality, and driveability. It totally transformed my car.
Putting EDIS on a V-12 requires two complete 6-cylinder systems - two coilpacks, two EDIS modules, and two crankshaft pickups, mounted 60-degrees apart. In the simplest case, it also requires two MegaJolts, which is the little micro-controller that actually controls the spark timing. But, it is also easy to modify the MegaJolt firmware to control two EDIS modules.
There is nothing about the EDIS retrofit that is fundamentally difficult, other than mounting of the trigger wheel and crank pickups. But, anyone who is reasonably competent at fabrication can easily handle it, using and off-the-shelf trigger wheel, and some simple metal cutting and perhaps welding. The wiring is quite simple, once you understand how the EDIS modules, coilpacks, and MegaJolt function. There is a wealth of how-to information on the web, as people have been doing these conversions for at least 15 years.
I first put EDIS on my E-Type in ~2005, and it has been pretty much untouched since then. I would NEVER go back to a dizzy.
There is a Pertronix system for the V12’s: https://xks.com/i-6918397-pertronix-ignitor-electronic-ignition-kit-for-jaguar-v-12-17-3664.html
It’s for a certain type of V12 distributor according to the ad from XK’s. If it fits it’s probably the simplest cheapest system available, as I suspect it bypasses the amplifier. (will your tach work then?) If you are having trouble with the amplifier there are solutions for that with a selection of new ones available that can “take the heat”.
Ray, there is a way to get away with one Megajolt, and that is to have a device that will “catch” the SAW pulse from the A-bank, then wait 250uSec after the falling edge of the PIP signal of the B-bank, then present the same SAW signal to the B-bank EDIS. This is what I did on my XJS (controlled by Megasquirt - but the same principle applies). I took this approach before Megasquirt-2 was developed for 6 ignition outputs.
There is a more elegant solution available now:
Megasquirt-2 (MS-2) can be configured to have 6 ignition outputs - for wasted spark on a 12-cyl. Then you need 1x trigger wheel, 1x VR sensor, 1x MS-2, 2x 4-channel Bosch ignition modules and the EDIS coil packs (3x 4-post or 2x 6-post). This has the benefit of having to tune only one ECU (and taking full control of EFI by connecting two more wires - should you wish). Of course Megasquirt-3 (more advanced than MS-2 - in some respects!!) can even have 12 ignition outputs for coil per plug implementation.
Has anyone fitted this kit? I would like to know how certain the installer can be that the PHASING of the pickup will be correct relative to the rotor (to ensure spark occurs when rotor is aligned with HT terminals), or if this aspect has to be correctly tuned during installation.
I have Paul, but the realities of shipping and customs authorities, make the development of a kit impractical. If I was based in the US, it would be a different matter. I do wish someone would do so though…
There are so many Jag V12’s that would so enjoy being set free of that atrocious OPUS/Vacuum retard ignition system. Having said that, merely fitting the ignition system from an HE V12 (Or Lumention etc) complete with a vacuum advance module, will achieve at least 80-90% of the distributorless solution - at a fraction of the cost, effort and complexity.
Again, the reality will be to sell one or two sets of plans which then gets distributed far and wide.
Anyway, its not about the money for me. I have already published much of the IP with the coil pack mountings (in the V) for the XJS. In the case of the E, one should try very hard to hide both coil packs and the HT wires to leave the V as clean as possible. Just imagine, a throttle capstan and NOTHING else…
If there is genuine interest, I could start a thread listing the parts, fabrication required and a circuit diagram. I’ld hope that the likes of Marekh would also chime in - if he has time.
Pertronix part numbers for the V12 are LU 1122A or 1121A depending on polarity, or for the Ignitor II 9LU-1122A or … 21A. I’m unable to find install instructions online for these.
At the risk of assuming “you” refers to me as per post #13…
No, I did not start a thread.
The ignition solutions for a V12 include:
Used Lucas system from an HE XJS or DD6 etc;
Plug and play system from Lumenition;
Pertronix system.
As per post #10, with the addition of a vacuum advance module (Part no JLM519 from SNG) , the ignition system will be SO GOOD, that to harvest the remaining 5% or so benefits that a distributorless system would bring, is hardly worth the cost and money.
“I’d hope that the likes of Marekh would also chime in - if he has time.”
Apologies - I have only just seen this.
There are only two problems with implementing a stand alone mapped ignition for the v12:-
1/ The trigger wheel and sensor needs to clear the belts on the front of the engine and the v12 has a multitude of different combinations of pulleys, spacing between belts and general lack of space forward of the timing cover. This means that it’d be easy to knock one combination on the head and then you’d spend a lifetime accommodating every other request since the etype v12s won’t necessarily have the same solution as an XJS or an XJ12, let alone then considering aircon, no aircon, smog pumps, different alternator locations, power steering belts sat forward or back…
2/ People don’t really want to pay for stuff anymore if they can help it. I did get asked to carry on supplying Ray’s kit after he stopped making it and was asked to do it for about half the price that Ray charged. I enjoy making things and helping people but one has to be realistic aswell. The only car for which this would be economic is the etype, as the cost of the conversion probably exceeds the market value of an xj12 and the xjs has only recently started going back up in value.
My car runs Megasquirt-3, fueled sequentially and running wasted spark ignition directly by the MS3.
And, oddly, the EDIS parts are, for the most part, actually more expensive, and much harder to get than than I sold my kits. THAT was the reason I stopped making them - new parts were prohibitively expensive, and used ones were very hard to come by in acceptable condition. Plus, the proprietary connectors were particularly hard to source, and declining in quality. The only (somewhat) reliable vendor I had for those went out of business years ago. It’s a wonderful system, and I would not give mine up for anything, at the price I was charging for the kits, I was making about five cents per hour for my time in making them.