Hi all, new member, first time post.
I have a Daimler Sovereign 420 from 1967. This is a little known model, looking similar to the XJ6 series 1, built between 1967 and 1969, but mechanically somewhere between the XJ6 and S type.
It's a great car, but it's 55 years old and shows its age in some areas. The last thing I want to do is have a totally modern car, it is a classic and will always be, but modern technology can smooth some of the rough edges and improve reliability. Jags were anything but reliable in their heyday, due in no small part to their reliance on Lucas electrics!!!. Furthermore, if modern tech was available when it was built, it would have been used.
So far, I replaced the distributor, as soon as I got the car for an electronic version, which looks identical. This made starting much easier. The clock is the original but contains a quartz movement as the original Lucas model had literally fallen apart internally. I dismantled the dash, cleaned all the illuminated insignia (some dirty water had got in and stained some of the Perspex/Plexiglass) and fitted LED lights, so the illumination bulbs should never blow again and the illumination works really nicely. I fitted an electric aerial and Classic looking DAB radio, with MP3 USB socket. I added 1960s clip on wing mirrors for safety (the car had no wing mirrors). I added a much larger rear view mirror, with bungee fittings so it can be removed, with built in Android GPS. This last mod definitely is not in keeping, but as it's on bungees and primarily for safety as the mirror is much larger, it's a compromise I can accept.
At some point the rear suspension coils and shocks had been replaced for racing adjustable coil over shocks. Apparently a few years ago this was a standard 'improvement' when original springs were unavailable to upgrade tired suspension. The ones fitted were good quality, but the shocks started leaking and it was cheaper to fit original spec springs and shocks. This made the car sit right and corner so much better!
Other updates I'm looking at are fitting EFI as the 2" SUs are worn and the AED is operated by a switch, which should improve reliability and fuel consumption. A side effect should be improved performance, so I'd like to reduce the diff ratio, for more comfortable motorway driving. Late model series 3 diffs with a ratio below 3:1 should fit directly. This would then require fiddling with the speedo input for it to read right.
The EFI I'm looking at retains the carbs, for appearance and uses a spacer between the carbs and manifold containing the injectors. Does anyone have experience with these type of injection kits?
I have considered a 6 butterfly multi point injection system, but as well as the additional cost and change to the appearance under the bonnet, I think I'd rather just buy a series 3 Daimler. I owned a series 3 Daimler Sovereign about 30 years ago. It was the second most unreliable car I ever owned, the most unreliable was a 1978 Range Rover!
The speedo mod I'm looking at is a GPS to mechanical unit, rather than re-gearing the drive. Currently the speedo wanders up and down, indicating the speedo drive cable is kinked. A GPS to mechanical unit should sort this out as well as giving the right indicated speed. Does anyone have experience of these devices? My main concern is how long it takes for the GPS to acquire and therefore to indicate speed and whether GPS reception ever drops out.
I have a modern car and it is easy when switching to driving these top of the range in their day classics to forget that they are so old. E.g. I fitted the wing mirrors because I almost had an accident pulling out on a dual carriageway. It was a beautiful day and I was enjoying the moment. I looked at where the wing mirror would have been in my modern car, but instead of my brain registering no mirror, it registered nothing conflicting. As I started to accelerate to pull out, a modern jellymould zoomed past!
Anyway, I'm not looking for criticism from purists, we don't live in the 1960s with 1960s unreliability, 1960s H&S and 1960s levels of traffic. I would just like to hear from anyone who has experience of the mods I'm looking at. I don't want an old body on completely new mechanics, I just want to make a slightly worn and slightly rough at the edges diamond shine a bit brighter in the modern world.

 

Hi LisaJK,
If you have a Daimler Sovereign/Jaguar 420 then you would get a better answer in the
"MKI / MKII S type 240 340 & Daimler" forum. They've talked of adding 420 to the forum title.
https://www.jaguarforums.com/forum/m...40-daimler-61/
Daimler Sovereign/Jaguar 420 is a refreshed/updated 3.8s/3.4s
I hope this helps

I love the Daimler Sovereign/Jaguar 420 and hope to buy one in the next year.