xjr v8 steel engine liner

It's more important when it was built in the first place and if your car was originaly fitted with a Nicasil coated block there's always the possibility it may have had the engine replaced under warranty at some time in the past - which should be recorded in the service history and by a (green IIRC) metal tag at the rear of the engine behind the throttle body. A replacement engine should also be show up on a Jaguar WDS scan too I think.

Very briefly there have been two versions of the V8 fitted to the '98 to '02 XJ8. The first AJ26 one had a Nicasil coating applied directly to the bores and allong with several other revisions at sometime in 2000, the later AJ27 version had steel liners inserted into the block.

Athough several engines were apparently discreetly changed wnder warranty, as far as I know Jaguar have never publicly admitted there was a problem with the combination of high Sulphur content fuel combined with short trips allowing errosion of the Nicasil lining to take place. Part of this reluctance included not supplying the information to indicate which engine was fitted to any particular car and so a whole number of suggestions, ranging from that build time on a particular day was the switch over point to Jaguar used up whatever engines they had in stock sometimes over a period of months have been made. Adding to the confusion is that Jaguar never clearly defined what constituted the difference between a manufacturing and model year - presumably as to do so would harm sales of old stock cars.

The main sympton of Nicasil failure is difficult cold starting and sometimes a lumpy idle. If you're concerned then any Jaguar dealer or indy will do a blow by test which indicated how much compression is being lost past the pistons. Over 40l/m is a fail and ideally you're looking for less than 25l/m.
Lots of oil in the breather system, air intake trunking and throttle body is a useful guide to engine condition too as well as excess crankcase pressurisation - lift the oil filler cap with the engine at hot idle, a clean, healthy enine ought to pull a slight vacuum and at worst there should be no or very little fuming or pressure escape - and even if there is it may be nothing more than a blocked breather causing it

One method that's often suggested is to look at the VIN number - if the last 6 figures are 1 letter followed by five numbers then you've got a steel lined engine. My June 2000 built car VIN ends like this but as some suggest steel liners were not introduced until September 2000 then it's difficult to be sure.

The main point really is your car, even if it has a Nicasil engine fitted can only have been exposed to the higher 150ppm limit of Sulphur content in fuel which, combined with lots of cold starts and short trips is what allowed the build up of Sulphuric acid in the oil that etched away the Nicasil coating on the bores, for a matter of weeks when it was first registered as the maximium allowable limit of Sulphur in fuel was considerably lowered by law on 1st Jan 2000.

There is a school of thought which suggests that Nicasil coated bores - obviously provided they have not eroded - are much better in terms of friction reduction and engine life then steel liners. Nicasil coating had been commonly used in both cart racing and bike engines for years and that's why Jaguar and BMW - who also had several engine failures - introduced it in their new engines.

My Brother had an XKR circa 98 with 65,000 on the clock it suffered from Nicasil failure , Cold start problems very low blow back test ,
it took a lot of time with the involvement of solicitors between himself and the indie he bought the car from to admit, there was a problem with the engine.

he was one of the lucky ones because as it had full FJSH . Jaguar replaced the engine at a cost of 8k ,

He was told if the car has under 100,000k and FJSH , jaguar would replace the engine , however this was back in 2001

Mmm... That ties up neatly with the claim made that steel liners were introduced in 2000, but not as I've seen suggested, a calendar but a model year which would have rolled off the lines towards the end of the previous year.

It's a bit too easy to worry a bit to much about all this 'tho. If an Nicasil engine has survived for the last 10 years since high Sulphur content fuel was phased out than chances are it'll keep going now 'till miles or a lack of care or regular oil changes kills it.

Agree with the last two posts. If it's Nikasil and it passes a blow-by test comfortably, then I'd be happy with that.

A guy at Jaguar told me that, perhaps he had his dates crossed and meant 2000, who knows exactly???

But I am in the nikasil camp I am rebuilding a 4.0ltr nikasil engine using a 4.2 crank/rods and pistons so effectively stroking it to a 4.2. Probably will have the only 4.2 nikasil engine around unless someone else has done it? Lets see how long I take to blow it up

Is it worth the effort just to keep the nikasil engine
The 4.2Lt has many other developments


Some of us know one owner who is making a 4.4Lt engine
Over two years later and still not on the road

And with your expertise and facilities

Ahh yes the compression ratio!!!! I have forgot to mention I am using XK8 pistons and have machined the tops to my own compression rating, I have also skimmed the heads.

I really have no idea if this will work, it is very hit and miss, I have done a few calculations but no real science behind it, all very old school, lets do it and see scenario

I may be wrong here... but didn't a replacement steel lined engine have a green engine number tag rather than just a silver one as fitted to original engines?