I have come across a 2007 XK that was overheated and apparently killed the engine. I am looking at options for the replacement and was wondering if can I buy a used engine from a 2007 XKR and replace the cooked one? Pretty sure the XKR ECU would have to follow the engine into the chassis. What say you?

 

The ECU and probably the instrument cluster also, if I remember right. That means also all the keys and such. I think.

 

This is why I hate dealing with the new cars, the total integration makes any changes difficult. I can see changing ECU for engine management and yes I see the key too but the instrument cluster? Why the instrument cluster?

Do you think the XK ECU could be reflashed for the supercharged engine?

 

Now you're beyond me. There are several guys in here that can answer this completely accurately, I'm not one.
Let's wait a bit, someone will come along.

 

I spoke with the folks at the Mina Gallery and he said the XK ECU didn't have all the parameters the XKR ECU had so his tuner couldn't be used on the XK ECU to overcome the deficit. Said get a car kit from the junkyard that includes the ECU and harness with the engine. Keys would have to be reprogrammed.

 

Wouldn't the block and heads from the XKR replace the block and heads, from the XK.? And everything else stays the same on the XK..

 

The XKR has a lower compression ratio for the supercharger.

I want to replace the XK engine for the XKR to get more horsepower.

 

It's a lot more than engine and ecu. Best to go back with the NA engine and or save for an R.

 

XKR ECU is different but is easily programmable and can be matched to your car. Will it work without issues? That I don't know, but it might not be worth the hassle..

 

Would be much simpler and cost effective to find a used AJ34 and have it installed.

 

One alternative if it is not a go, to switch for a complete turbo engine is that the block could be used in the XK and send out the old heads to be rebuilt.
Then the XKR heads could be sold off, along with the turbo. I am assuming the lower compression ratio in the R is achieved by the heads only.

 

There is no 'turbo' on the AJ34 or AJ34S.

Lower compression can be achieved by different piston shapes, not just the cylinder head.

 

I went through this with with many options being considered.

A n/a 5l got ruled out almost immediately along with a new gearbox being required (ZF6HP28) different bellhousing compared to the 4.2l and the nightmare of trying to get all the components to speak to each other was beyond me .

The 4.2 s/c was also considered however would have only went down this path if I was able to find a front cut as there's a little more then just dropping the engine in .

The Aston Martin 4.3 and 4.7 were also considered as these can get goinh with some modifications but at 20k or so for a 4.3l it didn't make sense.

I finally went down the track of a aj41 (2007 4.4 range rover engine) with a few modifications like drilling out oil pan for dipstick , swapping out injectors/ sump & timing cover it's pretty straight forward (If I could do it again I would have changed my camshafts to 256° items then perfect!)
All in all it runs over 102mph and 13.5 down the 1/4 mile now so not quite 4.2s/c but on par with 5l n/a .

Just some food for thought for someone who has been in this situation

 

yes you an refresh the ECU. The instrument cluster is the gateway for the high speed and medium speed Controller Area Network (CAN) and is also connected to the Local Interconnect Network (LIN) bus to the start control unit and the steering wheel module, along with a multitude of other modules and the CJB. If you don't have it paired, car no go.

I don't know your budget but you would prolly save $$$ parting out your XK and buying an XKR. Good luck and lets us know how you get on.

 

The bore and stroke on the XK is exactly the same as the bore and stroke on the XKR . Page 266 of the owner's handbook.
Bore 86.0mm and stroke 90.3 mm.
So if the turbo project become unwise, I repeat the idea of using the old heads on the XKR block. The compression most likely will be the same. Plane the old heads to make sure they are not warped for instillation on the XKR block.

 

This spells out why I hate working on modern cars. You can't change a dang thing.
I think my plan is to replace the engine with a stock junkyard take out. Keep the old engine and maybe rebuild it and add a supercharger for a 2003 era Land Rover Discovery project I had been planning.

 

It doesn't sound like you own the XK. If not, save up and buy a good XKR. Get the SC engine plus better suspension, brakes and exhaust.

 

It is true I don't yet own the XK but, it is to be gifted to me. I am not sure the XKR is what I would inevitably get. Perhaps the XK would fill the bill as is.