As I start planning on adding air conditioning to my 420, I am considering upgrading the radiator to one with more rows. The 420 radiator appears to be different from the 420G and Mk2 type radiators. Does anyone know of a company selling high-performance radiators for the 420? I couldn't find anything through my searches.
Assuming that the 420 radiator is unique, does the forum think that the header tank that sits on top of the radiator is necessary or could a pressurized overflow tank be mounted along the firewall if the battery or heater were relocated?

 

The 420 cross flow radiator needs no upgrading as long as it's clean & the separate top tank is in good nick. Jaguar fixed overheating troubles properly on the 420 & you have excess cooling capacity. On the 420 the thermostat keeps the operating temperature up to the required temperature. The car is overcooled. Don't waste your money. Make sure the radiator core is clean & the thermostat new & correct.

An aircon with a pusher fan on the condenser will be a walk in the park for a 420. Likely even without a pusher fan to aid the standard fan. I would keep the pusher fan if it's part of the kit for extremely dense traffic with a Thermo switch on it. No point in running it when not necessary. Just more noise. Preferably a progressive thermo switch so the pusher fan runs no faster than required. In the pre digital era such devices are available. Post digital dead simple.

 

If you do go to a remote header tank, make sure that it is the highest spot in the cooling system. That allows the air to bleed properly. Any hoses to the tank from the top of the radiator should be on a continuous upward slope to ensure that air can rise without being trapped anywhere.

 

JB ~ 420 separate upper tank on top of crossflow radiator, It's how Jaguar built them & the Daimler Sovereign. No issues de-aerating the system.

No idea why this car is fitted with a non Jaguar or Daimler oil cap. They took the trouble to make Daimler ribbed covers.


Early LHD car before the ribbed the cam covers.



Daimler Sovereign Ribbed Cam Cover fully cast & machined ~ no sticker.

 

I have seen some of the later cars like Series 2 E Types that had a plain oil filler cap. I think it's authentic item, just cost cutting at Jaguar.

 

Should not be a 420 item but I'm sure you are right out of Browns Lane. The last 420's were built in SA and had Jaguar oil caps. We were slightly late with the XJ6 launch as we tooled up for its production. By that stage some body pressings were being done here by Steelmobile. No longer fully CKD not that they ever were. Lots of local items on so called CKD cars.

 

I've seen those plain oil caps a couple of times but always on the ribbed cam covers
I wondered if Jaguar were trying to use a self-adhesive sticker on the cap in the same manner as the stickers on the cam covers but it didn't work.
I agree it was possibly a cost saving measure

 

You could well be right Bill & JB. They went to the trouble of making a Daimler ribbed cam cover & no oil cap ~ seems crazy. But so do many things in the BL & onward years. The Daimler ribbed cam cover is a fully cast & machined item on a purely XK engine. Why go cheap on the cap????? The Daimler spinners on wires were also the genuine article sans ears like the Jaguar spinner. A global car mainly for the local market. Benz protected the Daimler name elsewhere. It just makes no sense but that was BL for you. The Sovereign was the first fully badge engineered car. Nothing Daimler about it. At least the V8 had a Daimler engine.


Daimler Sovereign wire.

 

I was talking to a friend who owns a Daimler Sovereign version of the 420 just recently. He asked me if in my box of many parts if I had any Daimler badges. I asked which ones and he stated that he required the glass Daimler badge that went on the rear chrome plinth over the number plate. Now I thought that there would be separate chromes for the Daimler and Jaguar but apparently his Daimler badge had come off and been lost and underneath was the Jaguar badge as per the S type and 420.
So it appears that rather than making two rear chromes, they only made one for the Jaguar and fitted a glass Daimler badge over the top of the Jaguar one.


Jaguar S type and 420 plinth

Daimler Sovereign plinth

 

My father lost the oil cap of the Mk2 in the early 1970s. The replacement from the local Jaguar dealer was a plain one. Some years later, I noticed that other cars had Jaguar on the cap and bought a replacement.

 

Cass. Yes & no fluting like the Mk2 derived Daimler. Only the grill was fluted. I always thought the Sovereign was a very handsome car with all it's extras as standard right down to it's perforated centre on the seats upholstery (higher quality Connolly hide than the 420). And use of better veneer on the woodwork. Of course you had to pay! It was only built for 2 years/seasons but added another 4000 cars to Jaguar sales that they may have lost to Rover etc.. We have very few in SA as they were a full import. A Friend has a Primrose Yellow one.





The Flying Winged D



Daimler Dash.