I'm pulling off the head off my early series 2 XJ and while I was that far I was wondering if there was anything else I can do performance wise without serious modification.
Can I swap out cams or anything?

Thankyouverymuch...

 

Advancing the cam timing is a 15 minute freebie that'll add a bit of low/mid range torque.

I'm not an authority on camshaft changes/upgrades for the 4.2 but I'm not personally aware of any that would be appropriate for an XJ6. I'm pretty sure that the few choices out there are designed for high-rpm power gains.

Cheers
DD

 

As Doug says, there isn't a whole lot you can do engine-wise. When Jaguar put EFI on the engine in the very late 70s, they also put in the larger inlet valves originally fitted to the Le Mans cars; and that's about it ! The exhaust system can be improved a bit. AJ6 Engineering here in the UK take things further, but it is a bit costly and clearly no good to a US owner !

PERFORMANCE FOR THE JAGUAR XK 4.2 ENGINE. / AJ6 Engineering

 

The AJ6 Engineering stuff is great and is a big benefit for USA owners....or anyone else who can afford it. It works! I bought one the "Superenhanced ECUs" and it worked exactly as advertised. I couldn't afford the rest of the goodies but those who can seem to have universal praise.

The problem is that almost all of their products are for the *fuel injected* 4.2 engine which the subject car.....an early Ser II..... wouldn't have.

Cheers
DD

 

[QUOTE AJ6 Engineering here in the UK take things further, but it is a bit costly and clearly no good to a US owner !

PERFORMANCE FOR THE JAGUAR XK 4.2 ENGINE. / AJ6 Engineering[/QUOTE]

- Ahem hmm - Canadian owner - :-)
I don't mind looking overseas for performance upgrades. My car is a UK spec Australian XJ. I'll look into it....

Thanks for the input gentlemen.