If you already want more power, and are willing to spend some on it (i.e. go the hard way and not swap cars), I would go for the 2001 R engine as you need to replace anyhow the ECU, so make sure you get the ECU with the engine (and possible all the other parts needed to convert to an R).

The AJ27 has knock control above 3000 rpm, and is better in other ways as well, but the knock control is something that can safe your engine someday!

Here is some good info for the swap:
https://www.jaguarforums.com/forum/x...mplete-188633/

 

Thannks for the reply
can you tell me why you picked the 2001R when you have 2000 XKR that puts out some serious HP
and yes if I am going to have hassels ECU, wiring harness ect then I will make it a worth while headache.
I did read in the forums some one had an oil lead with the gearbox cooler pipes rubbing on a 3.2L 1998 same as mine
and a reply surgessted to check the valley and knock , what is this knock you talk about.
second do I eventually buy a aftermarket super charger or does the m112 fit the 4.0L 2001 motor
and Thirdly the VVT issue
Thanks again

 

No, what I meant was:
If you need more power, and don't want to exchange you car for an R (1st choice), then best is to go for a drivetrain swap and the 2001R engine would be a very good one then with all electronics with it.

For me the standard R power was not enough, so I added a twin-screw and enlarged a 4.2 engine to 4.8.

With knock control I mean the ability of the ECU to retard the timing to avoid further detonations if they occur for whatever reason. This is actually basic info you would need if you want to seriously modifying a NA engine (ie put a supercharger on it), so for this I would advise against it.

Though if you want to go that road, check out this thread:
https://www.jaguarforums.com/forum/x...d-works-49685/

 

Knock control is that what we call pinning advance or retard of timing or type of fuel used in an engine ?.
ok, so did you bore out your 4.2L to a 4.8L with the same original stroke?
can you tell me where to get a spec on the actual bore length of the 3.2L and the 4.0L in the actual block's for my knowledge pls.
you see in Australia the Jag is known as a beautiful eye-catching piece of machinery, but that's where it seems to stop.
This is due to the only Jag's that made there mark on the track (Bathurst I am referring to) was the v12's XJS coupe
so many people drop Chevs in them.
I won't do this as everyone has a gen lll 350 holden or ford boss engine.
I am sure with some advice like what you have given me and my background can achieve the looks and power to back it up.
with a Jag engine hopefully, that belongs to the classic time of my XJ
Thanks again the advice is much appreciated
I will check the link
Dutchy

 

Am not judging why you would do it, but certainly understand your reasons ;-)

Iirc only the stroke was adjusted for the 3.2, and I only bored out the block and left the stroke.

Get yourself also the workshop manual (JTIS), there you will find all the technical details including electrical diagrams.

You can also find lots of info on JagRepair.com - Jaguar Repair Information Resource

 

thankyou you have certainly steered me in the right direction
thanks to all who gave me a leg up on this project )
every time I ride in my car the more I fall in love with it
thanks for everyone's input