xk power output

[twincamxk]

Hello everyone, hope there is someone who can give me an answer. What is the power output of a series 2 4.2 xjg. According to several books I have looked at it varies between 170bhp and 245 bhp. Thanks all Nick.

[almcl]

Different systems were used for measuring the power depending on when.

The number of carbs makes quite a difference too. The SI XJ6 is quoted around 246 bhp gross at 5500, but this is with all ancillaries (alternator, afan, power steering pump &c) removed - as it was on the test bed.

The late SIIs (with the heated air intake, the HIF 7s) are quoted with all the bits in place. This varies from 165 (SAE) to 180 (DIN) depending on market. The SIII engines with FI managed to get back to 205 bhp (DIN)

The variations can also be down to market - the US emissions regulations strangled quite a lot of power.

[twincamxk]

So what is the tuning potential of the engine. If triple webers and a good exhaust were fitted for example, would that make a significant power increase?

[almcl]

I haven't tried, so can't speak from personal experience, but starting with a SIII might be better: it has 25 more bhp and Roger Bywater to help:

http://www.jagweb.com/aj6eng/xk_performance.php