Nikasil Liners. Hard starting.

[xjscharlie]

Hello Folks,
Just a general query why would Nikasil liners cause a hard starting problem? Rgds. Charlie.

[davidr]

In the days of high sulphur fuels their slight acidity would react with the nickasil liners and erode them to the point that the seal between the piston rings and the cylinder wall was insufficient to give adequate compression so the car becomes hard to start.

[Andy P]

Hi Charlie,
Just a bit more info on the AJV8 Nikasil engines from a P.D.F. I have from
http://www.racinggreencars.com/home
But I can't post P.D.F. files on here so I've copied it for everyone's pleasure.

Originally developed by piston manufacturer Mahle for use in the Wankel engine the Nikasil coating is a highly technical surface coating for cylinder bores and is still used extensively throughout the racing and aerospaceindustries due to its significant advantages.
The Nikasil process creates a layer of nickel-silicon carbide about 0.07mm thick, usually by electrolytic deposition,attached to the surface of the aluminium bores.
This nickel matrix is exceptionally hard, yet it is relatively ductile.
Dispersed through the nickel are particles of silicon carbide less than 4 microns in size.
These extremely hard particles make up 4% of the coating and form a multitude of adhesion spots where oil can collect as well as providing a long wearing surface for the piston and rings.
The silicon carbide particles contribute to longer engine life by ensuring good cylinder lubrication.
Nikasil offers superior lubrication, reduced friction, and improved wear characteristics when compared to
traditional cast iron bores.
Other benefits are that the Nikasil allied to aluminium provides substantial weight savings over cast iron liners and this combination is also very efficient at dissipating the heat generated during the combustion processes.
Where Nikasil was not fully tested, however, was in relation to cheaper fuels where the relatively high sulphur content allied to short periods of use of the engine caused the surface coating to break down.
This breakdown in the Nikasil coating was due to acids being created through the combination of sulphur and water in the combustion process and was exacerbated if the engine did not achieve normal operating temperature.
In severe examples the compression is lowered through leakage past the piston rings to the point that the engine will not start.
The Jaguar test to diagnose this problem involves measuring the combined blow-by of all 8 cylinders and should the blow-by be greater than 50 litres per minute with the engine at idle and correct temperatures then the engine will require replacing.
Once the problem became apparent Jaguar instigated dealer tests and replacement of the badly affected engines under warranty subject to service history and mileage. From 2000 model year on cars came equipped with the more traditional solution to bore construction and cast iron liners were again deemed the answer.
This is the practical solution to the problem but the loss of the Nikasil lined engine and its clear advantages over the conventional approach is a great shame.
Current fuels would probably have meant that this problem would never have become apparent.
The vehicles and chassis ranges that have Nikasil lined bores that may suffer from this problem are:-
XK series VIN range 001036-042775
XJ V8 series VIN 812256-878717
Note that Jaguar do not give chassis number ranges for the S Type but these were fitted with Nikasil lined V8s and as such it should be assumed that cars within the relevant time period may well have Nikasil liners.
Racing Green Cars have seen problems with V8 engines in S types and on dismantling these engines the bores have turned out to be Nikasil lined.
It is highly likely that engines from this period that have not already suffered any breakdown in the Nikasil lining may go on to last for substantial mileages with negligible bore wear.

I always find this stuff very interesting(or not as my wife would say).
Hope it sheds a bit more light on the subject anyway.
Take Care.
Andy

[xjscharlie]

Many thanx for that ~most interesting..Rgds.

[RichardSEL]

I'm moving on from XJ8 so my adverts contain these notes:
notes wrong

[XJR308]

I have a 2000MY XJR first registered in Sept 1999 and the engine number is F02166.
It was obviously built before August 2000 but has an F prefix. So is this steel lined or not?
Bruce

[RichardSEL]

I have a 2000MY XJR first registered in Sept 1999 and the engine number is F02166.

That's your VIN, not your engine #

It was obviously built before August 2000 but has an F prefix. So is this steel lined or not? Bruce

Those notes refer to the AJ-V8 3.2L although they did tie in with my '01MY 4L for its engine build date. Three versions were produced: AJ26, 27, and 28 -- dunno whether they were also Ford produced too. And as an XJR supercharged so may have been built at Browns Lane where the special runs were assembled.

My current AJ-V8 3.2L (aka Ludlow or the eBay bargain) has an engine # KB0104201742 = 2001 20th April 1742h

Best I can do for now

[Andy P]

Hi Bruce,
Here's some more info on Vin Number's and Engine Number's.
Firstly, the X308 engine number gives easy dating information. A typical number will be 010615 02:10. This indicates an engine build date of June 15th 2001 at 2:10

01=year
06=month
15=day
02=hour
10=minute

Secondly, there are two locations where the engine number was stamped, depending on the manufacture date. 1997 thru sometime in 1999 the engine number was stamped on the block casting next to the thermostat housing. Sometime during/after 1999 it was moved to a location on the block under the left-hand exhaust manifold.
The location under the left-hand exhaust manifold is easily visible if you remove the front left-hand wheel and look through the wheel well.

The Vin number can be de-coded as follows.

Hope that helps a bit.
Good luck.
Andy

[XJR308]

Thanks Andy
Yes that helps a lot.
Regards Bruce

[RichardSEL]

Thanks Andy yes that helps a lot. Regards Bruce

Yes, very useful charts. Thanks from here too. So the "F" in the VIN does not mean ferrous.
Must've been an old Jaguar wife's tale I've picked up -- mind you that's Coventry for you <run>