TK is of course refering to the beautifully designed but rather fragile 2.5 litre V8that was installed in the Daimler Dart(SP250) sportscar and also the Jaguar MK2 body as a more sophisicated option to the regular Mk2 jag.
This engine with a cast iron block and interchangable aluminium cylinder heads was a sweet running engine with all the Turner innovations like hollow dural pushrods and lightweight pistons compared with the Jaguar equivalents, twin point ignition, but unfortunately when dragging along a ton and a half of bobywork it had a propensity to collapse pistons with quite dramatic results.
My personal preference is for the heavier but not so delicate XK design of twin cam 6, though my wife has a love affair with the alloy SOHC V12, which I get the honour of keeping running(lucky aren't I?)

 

The design is maybe not so "delicate" because it came at the end of WWII.

Almost now, the transition from horse power to horsepower.

The Jaguar XK dual overhead camshaft (DOHC) inline 6-cylinder engine was introduced in 1949 and continued in manufacture until 1992.

But to be fair, a great legacy for any engine; there can't be too many engine types that have remained in production for that many years; a tribute to the original design by William Lyon. How many years was the A series Austin in production?

As for keeping your wife's V12 running ? It's just a cross you have to bear.

If you want the flash git trophy wife you have to accept that there will be a price to pay.

Your price happens to be a V12 E-Type, it could be worse; she might like shoes, How much fun would you actually get out of yours wife's new shoes?

I suspect that would be less fun than an E-Type