check this link

Jaguar's AJ-V8 (http://www.jagweb.com/aj6eng/v8_performance.html)

Jaguar's V-8 was revised for the 2003 S-Type, XK, and the new aluminum XJ. It now has 4.2 liters. It has more power, less emissions, better gas mileage, and has a stronger block than the old 4.0 liter V-8 which powered the 1997 Jaguar XK8.

4.2 liter supercharged V-8.

http://www.jaguarusa.com/us/en/vehicles/r-performance/Overview/overview_1CC97284-D0AF-43F4-BB5B-8649EEA8FE4F_462x669.jpg

The 4.2 liter V-8 is hooked up to a ZF 6 speed automatic transmission.

http://www.theraceforum.com/images/forum/3041-25-1.jpg

4.2 liter V-8

http://www.theraceforum.com/images/forum/3245-0-3.jpg

4.2 liter, 390 hp superchaged V-8 which is used in the 2003-2006 XKR, the 2003-2005 S-Type R, the 2004-2005 XJR, and the 2005 XJ Super V8. It has 399 lb-ft of torque.

The 2006 S-Type R and all 2006 supercharged XJs have 400 hp (new SAE [Society of Automotive Engineers] ratings) and 413 lb-ft of torque.

http://seriouswheels.com/pics-2005/2005-Jaguar-S-Type-R-Engine-1280x960.jpg

4.0 liter V-8

http://www.eng.ox.ac.uk/ice/aj-v8.jpg