Saw a video about that. How good is it to make that change for the engine? And how much would it cost?
Thanks in advance!
Assumingly,
You’ve got 4L XJS version so your gearbox is ZF 4HP24 which should survive extra power generated by supecharged engine.
XJR engines below year 2000 are first to discard. Nikasil-coated cylinders and cam tensioner problems along with British workmanship makes these a great unknown, regardless of mileage.
You’re looking at ECU and wiring swap, non-standard torque converter, possibly clearance spacer plate between engine and tranny, these are the big jobs, the rest can be minced-in.
If you’re able to make most of conversion by yourself - the costs would be limited to sourced, complete engine.
Don’t go that route if you’re willing to pay someone to do it - too many variables and too many potential rip-offs on the way. Probably, much better and cheaper would be to supercharge your 4L engine, the value retention will also increase (swapped XJS will actually drop severely)
All XJR engines are usually abused with British production standards fully ‘diversed’ on R&R. Just mentioning…
Janusz,
From what I read, sulphur was the cause of the Nikasil problems. During testing, Jaguar, in the UK were using UK-gas, which was lower in sulphur. Then by the time the car comes out, sulphur was being added to gas at much higher percentages. Problems for this engine for sure, and Jaguar stopped using Nikasil by the time 2000 rolled over…however something else happened.
Gasolines started to reduce the amount of sulphur in gasoline. I have read that by 2004 sulphur amounts dropped 75-90%, then in 2017, it dropped to 10ppm. (Not sure what that amounts to in percentage, but probably ‘trace’)
It’s probably a safe bet that if the Nikasil engine exists and runs today, it may be a good engine going forward.
Thank you very much for the information!
Didn’t the AJ16 have iron liners? I thought Nikasil came in the first V8s.
It’s my understanding that, add a 2nd supercharger, and that’s pretty much what the XJ220s came equipped with. 
Vee,
Nikasil exists and runs till today - in high-end engines made by f.eg Porsche or Ducati in those years. Mostly in monumental collector’s vehicles.
Recent experiments with coating instead of liners - made Volkswagen famous - their engines went on top of World’s Worts Motors Ever Made list. Jaguar was not even close to VW that time. Historical experiments of BMW eith their V8, trying to catch up with Porsche - ended up with recall and replacement of the engine to the V8 with standard sleeves…
Unless you have red 911 turbo, avoid nika-bull-silt.
Another thing worth noting - these days engines are “tuned” / alt. "cheated for the ultra low emissions designed by the other cheaters greenwashing the perpetuum mobile industry. Design has changed, same as the materials used. That also includes fuel, oils and fluids in your car (you don’t think they’re bothered with “classic car” owners, do you?) Everything that kills the old cars will be awesome and quickly approved/implemented. That’s how you’re making money from sales these days, that’s why your engine oil has no zinc and your fuel has plenty of alcohol…
and, to follow up that question (and I know this probably should be on the XJ220 forum), are the superchargers divided up so that there is one per 3 cylinders (i.e. bank) or are they connected “in series”, one after the other? 