what are the difficulties in swapping a 5.0 n/a engine from a 2012 xj to a super charged 2011 xj?---------thanks in advance

 

Mark, the physical swap is pretty straight forward. You would need to swap over most of the top of the engine since you do have different cooling paths and other things like that. But, the block is fairly common. BUt, this is where your problem is going to lie. The internals of the block are different between the NA and supercharged versions. Different crank, different pistons (supercharged is less compression)., etc. So, if you take a NA block and put the supercharger on it, you are likely to at a minimum have an engine that is going to run rough. Potentially you can damage a block.

If you are saying that you are taking the whole engine and swapping that in, like I mentioned above, you are going to need to convert over a lot of the cooling piping and whatnot. Then your issue comes in that you will then need to get the ECU reprogrammed to handle a non-supercharged engine. You can't just swap the ECU as there are numbers inside the ECU that the car checks every time you start the car to verify that the car is not being stripped of parts and sold.

So, can it be done. Yes. But, it is not going to be a simple engine swap though either. You are going to have to swap a lot of things over.

 

The cost associated with this is astronomical compared to just selling the car and buying an XJ S/C. You're about to throw a ton of money out the window as well as suffer a lot of significant installation and tuning issues. Sell the car and buy an S/C. Take the money you would've spent on the swap and use that for mods.

 

That is correct for the 4.2 litre engine but is it for the 5 litre? My mechanic has taken a block from a Range Rover and fitted it to a 5 litre XKR. Some of the bolt on items have to be changed but the basic block is the same.

 

What Thermo stated in post #4 is absolutely correct. The internals as well as the ECU etc are VERY different between the 5.0 NA engine and the 5.0 SC engine.

The SC engine has a compression ratio of 9.5 whereas the NA engine has an 11.5 compression ratio. Which obviously means something is different internally between these two engine types.

Looking at my workshop manual the bore and stroke is exactly the same for the SC and NA engines so would presume the crank is the same.

 

I haven't looked, but the common ways to adjust compression ratio are; different pistons, chamber size and shape in the head.

 

Eric, in the case of the XJ, this is all done with the shape of the pistons. The lower compression ratio is needed to prevent knocking (pre-detonation, diesel effect, whatever you want to call it). You start pushing lots of air into the engine, when you go to compress it, you reach a point where the pressure rise starts getting too rapid, it will cause any combustible thing (oil, left over exhaust gases, etc) to spontaneously burn. You lower the compression ratio, you slow the rate of pressurization.

jackra, I seem to recall seeing at one point that the SC 5L motors have a forged crank where the NA 5L motors have a cast crank.

 

Here is the difference in piston design between the NA and SC models. As posted above this is just the tip of the iceberg concerning all the differences between the two models.




The 5.0L has forged rods but cast pistons and cast spheroidal Graphite iron crankshaft.






This is from the 5.0L technical guide which will answer all the questions about what's different.
But listen to the advice already given. Sell what you have and purchase the SC model you want.
.
.
.

 

I read somewhere that the V8 XJs can't have 4WD because the transaxles can't take it.

 

Well it can't be that considering the other cars Jaguar built with AWD.
It's kind of a mystery to me because Jaguar did install AWD on the F-Type using the 550HP 5.0L SC engine. Yes the XJ is heavier so maybe the added weight was considered too much. But again the F-Pace SVR (Even more power at 575HP!) also had this same drive train and it's heavier than the XJ at around 4655 lbs.

I think the real answer is lack of demand for an expensive variation of a car that did not sell. The rumors I have heard is Jaguar lost money on every X351 they sold as production numbers never got to the level they were forecasting.
.
.
.

 

Perhaps you're right or part right. I recall a detailed discussion about it on another Jaguars forum about the possibility of fitting a V8 from an F-Pace SVR and the consensus was the weak XJ drivetrain issue. In any event, I would love to have a 2019 Supercharged V8 AWD XJL SVR!

 

There are no "weak" drive train components in the XJ? Now I will agree on weak cooling system components!
All the rear ends, transmissions and engines are shared across the entire JLR product range. Again the F-Pace is even heavier than the XJ so Jaguar has the correct hardware and it will hold up. They just decided to not offer it on the XJ in V-8 form.

Yes with the power we have in the XJR and above putting the power down is a major problem on the street. AWD would have been a nice addition for sure!
.
.
.

 

When I was in London for the Feel XE event (world premiere for the XE), I got talking with an old man who was high up in Jaguar and asked this very question. Now, keep in mind that this was 2015, but at the time, he said that Jaguar had considered it, but that the transfer case for the XJ was only rated for 458 hp. So, they would have needed to de-tune even the 470 hp 5.0L to make it work. Now, as time has gone on, Jaguar may have gotten its hands on a more stout transfer case. But, by then, the writing was on the wall for the XJ and if they were already loosing money, adding something like this would have been out of the question.