Hi, another question from my novice self as I continue on my search for an X308 XJR...

It’s been suggested to me by a very well respected and experienced Jag restorer in the UK that it is preferable to try and get an XJR with the earlier Nikasil linings as this earlier iteration of the AJ26 / AJ27 performs ‘better’.

Just wandering if anyone agrees or disagrees with this suggestion? Is the difference in performance really that noticeable compares to the steel lined later engine?

I’m just really nervous that with my relative inexperience of these cars that I might buy a car which on the surface seems to drive nicely but which actually may end up very quickly needing a replacement engine!

Any thoughts very much appreciated!

 

The Nikasil engines have low tension piston rings and do seem to rotate with less force when turned by hand.

The Nikasil liner is claimed to be harder than steel so should last longer?

Overheating and high sulfur fuel are the main reasons for failure.(or poor maintenance)

I have 2 Nikasil engine XJ8 and one with a 2002 iron liner engine.
They all run fine and don't use much oil. (5W30 or 5W40)

 

I’m fairly partial to the nikasil lined engines myself. 262K miles on the original engine in my 98’ XJR. Thats not to say the steel lined engines aren’t bad either. I worked on a customers 03’ VP with 331K miles on it at least 2.5 years ago. It really is up to how the car was maintained and if there was no indication of an overheating situation, then it should be fine. I strongly recommend getting it checked out by a Jaguar specialist prior to handing over payment.

 

Only thing that matters is the condition of the timing gear

 

The risk if going for a Nikasil engine is the possibility that the Nikasil was "eaten" by the use of high sulphur petrol. However, this is fairly easily detected by a compression test and I would definitely do one if considering buying a Nikasil Jag.

In any case, I would look for an XJR no older than 1999 as the chances of its Nikasil affected by the sulphur would be smaller. In the UK, the low sulphur petrol was introduced from 1 January 2000 Nikasil engines that survived up to this date are fine (subject to good maintenance, of course). Perhaps a low mileage 1998 would also be fine.

The last Nikasil engine was produced on 17 August 2000. The first steel lined engine had engine number 00 08 18 1043 meaning Year 2000, Month 08, Day 18, 10:43 am. Any engine number prior to this will have Nikasil.

 

I wonder how much impact a low or high suphur content (SAPS) in the oil has on the Nikasil coatings over time. Any ideas?