Forum,
For a ‘75 XJ6 Coupè, S2, 4.2. I’m converting from Lucas 45DE6 to Lucas 22D6 dizzy. Opus (factory), Pertronix (9 years ago) EIs have failed. So now I am converting to the earlier points distributor. The EC changes are no catalytic converter and disabled ERG. I am not building the dizzy but anticipate it will use 3Ω coil, no ballasts or amplifiers and vacuum advance, not retard like EI. The dizzy builder will set the power curve.

My question is, what do you think about using, or not
using, the existing thermostatic vacuum switch?

 

Why not use a Series III style pickup and the module that works with the 45 style distributor? It's a GM HEI module and will probably last the rest of the life of the car in a 6 cylinder application. V12 is a different matter, they don't last as long there. I've seen plenty of Series III cars in the junkyard with the original module.

Points work, but you need to reset the dwell every 2,000 miles in my experience as it's always wandering due to to the rubbing block wearing. The maximum current the points can carry is about 2 amps, while the HEI module can carry about 7, so it's a much higher energy ignition . With that you can have a bigger spark and the plugs don't foul as quickly.

I've not worked on a Series II, so I'm unsure what the thermostatic vacuum switch does. Is the car still on carbs, or converted to EFI? I'm wondering if the switch is for the fuel system or ignition? Some of the V12's had a system to retard the timing to make the engine warm up faster, that could be what it is. You could probably get rid of it, if that's what it does, just make sure your thermostat is the correct style - see the XJS forum for that, as the V12 uses the same thermostat as the 4.2. The Waxstat thermostats are too short to properly block off the bypass passage.

 

Jb,
Since I had two EIs fail in 38,000, the cars lifetime miles, I’ve decided to change. However, thanks for pointing out GM HEI reliability. I’m hoping to keep my 45DE6 dizzy just in case. I’ll check out the GM HEI system.

Quality points last longer, but agree still some maintenance. When plastic block points replaced fiber blocks they gave points a bad rap. There may be other cheapening measures involved.

The TVS is for the ignition, it controls the retard during warm up to improve emissions control during rich mixture starts. Yes, I was thinking bypassing.
I would have to check the thermostat as to what it
is. Same concept on the MGA Twin Cam for faster warmups.
Thx,
Bill

 

I have the Crane Fireball XR700 in my '75 Series II 4.2L engine. It works outstanding - and has for over 20 years. Zero maintenance!

Crane Fireball XR700/XR3000 Points-To-Electronic Ignition Conversion Kit NIB ! | eBay

 

Y…,
Thanks for your input.
Did you keep the 45DE dizzy?
What coil/ballast setup did you use?
Bill

 

Don't have the dizzy. Have the stock Jaguar points distributor. And use the Bosch Blue Ignition Coil 9220081083

 

Y…,
So, Lucas 22D6 with Crane Fireball EI?
I have same Bosch 00012 on order, Monday.
Bill