Has anyone done this?

I'm assuming that I'll only use the "long block" from the newer donor motor and plan to transfer intake and all the other stuff from the older motor.

The big question is....will the PCM have an issue with the minor increase in displacement?

Is this a nightmare in the making?

Ken

 

DO you rally mean an '03? I thought those were 4.0 liter. I believe the biggest problem is the VVT control system whch changed from a discrete to a continuously variable design at '99.

 

For the SC engines it is relativly easy to use a 4.2 block in a 4.0 car, here is a link with some more info.
https://www.jaguarforums.com/forum/s...ad.php?t=23763

The increased volume is of no issue at all, there is enough room left in the programming. Only thing that might be difficult is to get the 4.0 manifold to fit nicely on the 4.2 heads. Probably good to start with a secondhand manifold first.

Good luck.

 

Any AJ27 engine will fit an AJ27 car and the 1999 to 2003 XJ8 engines are all 4.0 here in the U.S. so there is no increase in displacement. You can put the engine complete and it should just be plug and play.

bob gauff

 

Just to clarify...The engine is coming from the first year of the newer body style Jag. The owner told me it's an 03. Is that the first year of the new body?

 

The car may have been made in 2003 but if it is an aluminum body XJ8 then it is a 4.2 and registered as a 2004MY here in the US.

bob gauff

 

Here in the EU Jaguar actually calls it (the x350 Alu body) a MY2002.5, but in common terms we call it a MY2003. The actual build dates started already early 2002.

 

Yes it is from an aluminum body XJ8. So that means it's a 4.2 liter.

Does this present a problem if I'm transferring all of my stuff onto that long block assembly?

Ken

 

Most details are in the link provided, but I have not heard of anyone that has done it yet with a NA engine (maybe Bob or JTO or others may know?). Areas of concern are the intake manifold, and maybe the choice oil pump.

You need to work on the intake manifold. The SC cars have an aluminum intake manifold that attaches to the heads, and it is easy to port the 4.0 ones so they fit the 4.2 heads. With the NA cars the intake manifold is plastic, so that might be a bit more difficult to match depending on the amount of material you can remove to port the manifold holes to better match head intake openings. It will be obvoius for you when you see both the heads and manifold.

I assume (am not sure) that the VVT of the 4.2 engine is about the same (regarding oil pressure/volume) as the AJ27 4.0 ones. If that is the case you need the oil pump from the 4.2 engine for sure, as that one also takes the volume/pressure into account for the extra oil jets it has (like under the pistons).

Other than that, as you bring over the vvt/camshafts/flywheel/electrics etc, all will work, and the very small increase in volume is not enough to reach the limits of the ECU...

Andre.

 

Questions like yours have been going around the Jaguar Enthusiasts Club here in the UK where owners also want to swap to the newer (and better) 4.2 engine. Prognosis from the techies is that it is not wholly straighforward, but I don't know the details, maybe another UK owner knows more than me. Jaguar made some very subtle changes over the years, so tread carefully !

 

NA, not Europe -

The intake manifold setup of the 350 (4.2) is completely different than a 308 (4.0) in that the TB is located in front like an S-Type with a throttle by wire setup. It will not be transferable nor compatible with a 308 ECM.

If everything else fits, the older cable driven intake TB setup has to be reused, but I am not sure of that compatibility. 99 was a transition year. If the original engine is an AJ26, then there are going to be a lot of challenges with VVT, cam sensors, I believe crankcase sensor too, to name a few.

I personally wouldn't try an AJ26 swap to an AJ28; but, AJ27 to AJ28 might have a chance past the IM issues.

 

@SteveTech

I agree when you are talking about changing electronics etc, but that is just not the case here, and that is the main misconception everyone seems to have. Please note there have been numerous 4.2 blocks put into original AJ26/AJ27 SC cars, have done my car also.

It’s probably me that is not able to bring across what I mean, but I never suggested using the x350 4.2 intake.

Forgot that you could interpret NA as North American ;-)

NA=Naturally Aspirated
SC=SuperCharged

You can (should) reuse all of your AJ26 electronics and some specific hardware like: VVT/camshafts/cam cover/ignition coils/camshaft position sensor/flywheel (I know it isn’t a real flywheel, just don’t know the right term)/front engine cover/oil pump/oil pickup/lower bedplate (the part where the oil filter and pan is attached to), etc. Just have a look at the link provided that gives the full list.

You should also reuse your 4.0 intake (and that includes injectors TB etc), but to get an optimal airflow you need to do some porting as mentioned.

You can also use the x350 intake and new TB, it would actually be an option if you want the best possible solution (besides just to use the 4.2 block). Unfortunately it would require more work (new fuel connecitons etc), and possibly an ECU tune to recalibrate new fuel injectors that are attached to the x350 intake).