I got a few IMs asking about high performance mods on the JV6. First of all- it was NEVER called the AJ30- like Wikipedia claims- it was the AJ61 (the AJ30 was the Lincoln 3.9 Jag based V8). The AJ67 was the supercharged X type V6 which was cancelled.
I thought I'd outline the mods I'd do for a NA X type V6 and how to get there.
All data above is BMEP data measured on an engine dyno (at Whitley) about 20 + years ago except the “X400SS” curve which is a target curve I made up from the above.



I usually like to use Vol Eff data but I’m inputting this into vehicle simulation- so it’s more convenient.



X400= 2001-2009 Jaguar X type 3.0- transverse application- AWD, continuous denso VVT. Rated at 231 bhp, but most actually make around 218 bhp
X200= 1998-2001 Jaguar S type 3.0- RWD longitudinal, 2 stage VVT, rated at 240 bhp, but some made close to 250 bhp

X202= 2002 onwards Jaguar S type 3.0 (with new intake manifold with reduced throttled volume -down from 9 litres to 7.5) and VVT is continuous. RWD Longitudinal. 240 bhp, 12.6 bar BMEP

X600 was a middle engined project I was lead on- the original light weight F type- which would have used the X400 transverse powertrain. I managed to get about 190 kWs out of this- NA from a 3.0 Probably close to 260 bhp if take as DIN rather that SAE. This project got cancelled unfortunately.

I know I shouldn’t be spending money on my winter beater but I have so much data and legacy on this.

The X400 and X202 base engines, cams, ports are all identical

You can see how terribly bad the X400 is compared to the longitudinal X202 was.

• This is down to Ford forcing us to use a Y piece and single exhaust due to some irrelevant design guideline- this adversely effected torque up to about 2500 rpm
  
• The back pressure going from about 250-300 mbars up to 500-700 mbars (depending on the bank!) and
  
• Due to a know-it-all project guy not understanding that packaging alone doesn’t allow a V6 intake manifold resonate the way it should and DID on my X200 and X202 dual mode intakes (the X400 is still quad mode but two of the modes don’t work well!).
  

For the X600 I used the X400 base engine, had the back pressure dialed down to 400 mbars, may be less, went dual separated exhaust and used the very low loss intake airbox from the XJ6 series. I didn’t do a resonance type manifold but focused on low restriction instead (this is why the X600 doesn’t quite have the peak BMEP of the X202 and X200). The X400 X type peak BMEP is low due to the poorly designed resonance manifold and we also found that the excessive back pressure hit peak BMEP hard also (at those mid level rpms the vvt optimized overlap is quite high).

When the X600 F type was cancelled along with the super charged Jaguar X type”R”, me and SVO ended up putting the X600 mid engined Powertrain back into the X type as a ‘super sport’ mid sporty car. For that project I designed a more aggressive cam. Stock cam is 246 Intake period and 249 exhaust, (exhaust is pretty long as standard), and my reprofiled intake cam (shown below) is 252 IP. The supersport also got killed while Jaguar/ford focused on exciting diesels






My plan is to resurrect the super sport.

Shouldn’t be too difficult, I’ll get two intake cams made (unlike the Jaguar V8- there are cam blanks readily available for the direct acting Jag V6), get a separated exhaust system made up, split to the rear tanks, and use Alfa Romeo 159 GTA rear exhaust silencers (the Alfa has the same firing order as the Jag, same drive train layout – Fiat foisted a nasty transverse platform onto them too and they tried to make it handle like RWD also, and very similar exhaust valve opening point on the cam profile), modify the very lossy standard X400 intake airbox- as per some testing and simulation we did:






The intake losses across the airbox for the exceptional X202 S type were only 28 mbars! For the X type it went up to 57 mbars at peak power- most of the losses were at the entry (only a small part of the air cleaner element was being used and there are a lot of re-circs with the box

We’ll see if we can’t shoot for 260 bhp plus and this shouldn’t cost much either. The 32 bit Denso ECU is accessible too.

At the moment the 0-60 is about 6.8 seconds. I should be able to get it down to the mid to high 5s.

 

Awesome! Thank you very much for posting this

 

I've been trying to glean as much as I can from the specs for the Mountune developed race AJV6, the Noble M12/M400, the original Duratec 2.5L race prototype, any high performance Duratec V6 build-ups, & Aston Martin V12 engine designs, particularly the AM21. Been trying for a while now to get a good look at the cylinder head assembly to see if the kept the pent-roof design or went with something else, but I've had limited success so far. Since it's the only V12 that utilizes DAMB heads, it's possible/probable that the R&D from the X600 made it's way into it.

It was stated in the specs for the One-77 that the combustion chamber was machined, the inlet valves went to 12mm & exhaust valves to 11mm, with a bore increase to 94mm. Was thinking about trying to mimic those specs to an AJ-V6, but wondered if you ever experimented with bore sizes during your development testing. On a side note, any thoughts on piston-guided rods in an application like this, besides it being overkill?

 

Hi, I'm sure Aston did learn from us. Mazdas DAMB engine had a lot of commonality with ours and it only came to my knowledge much later. It's likely the same with the Aston. The valve angles and head geometry on that engine are probably almost exactly the same. In the FOrd empire- its much much lower risk to use something that's proven than undertake even more single cylinder experimentation and validation.

We looked at piston guided rods they're supposed offer some frictional benefits but its probably marginal. If its easy to implement- I'd pursue it, if not, Im not sure I would.

The bore centres are 102 on this engine, so provided you have a decent cylinder head gasket that seperates the bead between bores, there's enough cover factor for good sealing. Only other thing to look out for is the water jacket. 94 seems fine.

If I were doing a one off custom- I'd probably get custom pistons at 94mm and go an extra 2mm on the stroke.

In production for the JV6 upgrade (which got killed)- we were looking at a 3.2 litre V6 with a 92.5 mm bore. It was to be GDi.

It got canned because Ford didn't want invest the money at a time when Jaguar wasn't bringing in their high target revenues they wanted. It was planned to be slotted into Land ROver variants too (and I would have probably prefered it to the ridiculous AJ126 solution).

It got canned- we had to lay off a bunch of people. There was a time when Volvo was tasked with putting their incredibly huge and tall 'Short I6' into the X202/X250 platform. Volvo assured them they could do it. A year down the line when we'd already laid off a bunch of people, they came back and said they couldn't meet the 'aggressive' power and torque targets (no surprise when you look at the pitiful power and specific torque their engines have always piddled out) and had to turbo charged for the lower models. At the time- this wasn't going to fly. I wasn't upset when the Short I6 into S type replacement (XF) got canned and they soldiered on with the old JV6. That was a very different Jaguar. A Jaguar where quality was still high on the priority list, where we never would have dreamed about killing our own engines in favour of a BMW twin Turbo-regardless of its credentials :-(

 

Count.
Have you done any research on the Ford Cyclone engines and now the latest generation EcoBoost engines? I have been slowly researching the latest generation Ford engines and that they might be able to replace our Jaguar engines.
Everything I read says the new engines use the same basic block dimensions, but have been beefed up internally and have new DAMB direct injection heads. Ford makes transverse versions of these engines with a 6F55 6 speed trans and associated PTO. Possibility exists that some of these part could be adapted to fit onto our V6.
(My research to date indicates that the new engine with trans and PTO may be 2" too wide to fit in our engine bay. - Wider transverse transmission)
But we might be able to learn from what they have done to up the HP so much in the Duratechs and Ecoboosts.

 

Just tried to add a post and it vanished, so if this duplicates, I apologise...

@Count Iblis ,

Thank you for sharing this. I came across this whilst trying to look up exactly what my Cleveland V6 is, having looked internally and not been able to find anything.

As somebody spending his daytime at CV3 4LF, I'd really love to catch up and pick your brains about what may or may not survive here still regarding your work streams.

In my non-work life, I have a 2.5 estate that's been near enough killed off my an LPG conversion so I'm about to swap it with a 3.0 engine that's off a fractionally newer car, although weirdly has a different fuel rail which I can't find any record of in CAD and will clash with the J1 engine cover I retrofitted to mine without any issue (deleted for 04MY).

Finding this thread though has given me a 'burden of knowledge' problem, because as I am about to do this swap, and with that gross 'Y-piece' between the hot ends and the flexi in dire need of replacement, I was already having night sweats at the thought of having to actually pay for the privilege of fitting another pipe with the pressed looking joint. It all clicked as a I once owned an A4 2.8 quattro that had two pipes run all the way alongside the prop before joining at the fuel tank and only serving one back box, and the same with a 330Ci in the family, albeit that from an i6, not a V. So, if there's anything that may have made it as far as CAD, I'd love to see it, or appreciate any guidance on the best way to join the two banks close to the exhaust or things to avoid? Now would be the only sensible time to do it...

Airbox-wise, I thought the surviving SVO-built R wagon had the triple feed airbox, but my pics from Gaydon don't support it being used, so I'll try and see if there is an geometry for the 03MY core offering, as I do recall something about an extra feed into the box very similar to what you have mocked up on your image.

Have you had any joy recreating this on your actual car?

Final question, for now, the resonator on the rubber-flexi duct between the airbox lid and throttle body; do you know if it's purely there for a resonant issue, or does it benefit, or more like damage, performance by disrupting airflow?

There are very few people left from those days so my source of contacts is even decreasing to ask questions, so it would be exceptionally good to hear from you!

 

That’s weird about the fuel rail: my understanding is that the S type and X350s went from 32 bit denso ECU to an ‘emissions upgrade’ that was PANPAG to get through emissions (torque based).



The X400 to my understanding soldiered on with the 32 bit as by this time Jaguar had given up on this car and all but left it hung out to dry.



As for the exhaust the SVO ‘super sport’ NA car went for a single external pipe but it had a separator inside effectively making a ‘double D’ within that pipe. It stayed separate up to the rear tank.



It may be too specialist to get that double D made up, so I would just keep a dual system up to the rear tank . I wouldn’t go bigger diameter than twin 48 mms each (Yes I know the X400 2.1 uses dual 51s but that was a huge mistake!- it lost a a lot of low speed torque).

Then once I got to the rear tank- I’d go as big a diameter as possible- as by that time tuning effects/low speed torque isn’t effected by the system geometry (or more precisely- it tunes below the rpm range).

So you might as well focus on lowering the X types considerable back pressure back there.



The airbox I showed a picture of- was a development done at Mann and Hummel for the X450 3.2 litre car (under Wolfgang Reizle) but was canned. I don’t think or rememeber what the X400 “R” variant used. I wouldn’t pay too much attension to that red estate car for show- no one knows what build level that was- and it was probably put together hastily for publicity and show purposes- nore sure how technical the people were and how fastidious they were in adhering to AP, SP and CP (old Ford speak- for stage gates) level specs.



Knowing how non technical other depts. Can be at Jag….



I haven’t built this mythical car yet but may do in the future. The car is worth so little- considering how much I put into it, Im probably gonna keep it. It has zero rust although I no longer need a winter car.

My plan as to do the above, including the air box mods, and exhaust, use Alfa Romeo rear silnecers- something like a 159 V6 Q4- as the firing order of their V6 is identical to the Jag V6. I’d either use that one or a super sprint Alfa type. The X types in dire need of lowering the back pressure. The X200 really is a lot better in that regard.



Eventually, I’d probably bore out the engine and offset grind the crankshaft to get a 3.4 litre motor.



But none of this is cheap.



The mechnicals would probably be ok, as long as stuff was kept lubricated. It was all sized for the X400 R which never appeared and even a good breathing 3.4 litre with dual exhaust and free breathing intake wouldn’t approach the torque of that X400 R.



The other aspect that needs looking into is the throttle body, its way too small a diameter (sized for idle speed smoothness) at 60 mm.

Anyway, I hope this helps.



Cheers and good luck!

 

Great to hear from you!

Fuel Rail Current: note horizontal connector centre left of image


Fuel Rail Next: Connector now angled, extreme LHS of image


Only real hassle here is the newer condition writes off the engine cover in that area, or at least needs a cut out. I could swap the rail from the 2.5, but means taking it off the injectors again, and as you may know, the brass-nutserts in the lower plastic intake manifold aren't the best if you have to keep taking the upper ally one on-and-off constantly. The 3.0 is out of a newer car than my 2.5 but only by months and they're both 'E' series VIN numbers. Weirdly, or perhaps not, there's no CAD for the revised fuel rail condition.

On the 32bit, I don't know if the changes would be visible but the late modules, although having later MY prefix, down to the casing level the PCM is still as per job one. Same info on X200 suggests the PCM changed at 06MY to a new housing and connector head which as you suggest, by this time all X400 focus was on diesel sales until end of life realistically, I don't think NAS markets even saw the 09MY facelift (I was about to say MCF but more like LCF!), the 3.0 was still available in the wagon body in the UK, but I do recall seeing a 3.0 stunning blue 09MY saloon being built at Halewood that was destined for Japan!

I've had a bit of a play on CAD with a twin design but trying to do all sections with all bends on a single plane to give me a chance of assembling that, which I largely can until I get near the prop centre bearing which is when the package gets really tight, so I can't get back to the fuel tank, but I could get a Y-piece just around that bearing and that would leave enough space for a single centre resonator between the bearing and the tank, my car currently has a stainless potentially more performance oriented replacement for the original 'toblerone' shaped one; somewhere in between the car being built and me owning the car, some absolute muppet had paid a Powerflow franchise for remove the rear silencers / mufflers so they'd cut them where the pipes enter and put a straight piece of mild steel on from there with some stainless tips, including a horrible angled bend, and in the centre section, they'd got some generic no-brand resonator replacing the original which, when it started to rot away, I removed and found someone had taken what looked like a tin / can-opener to the top side presumably to remove the wadding but make it look more standard to an MOT tester from underneath... another option might be to twist the two pipes through 90deg such that by the prop, the two banks are vertically aligned rather than horizontally aligned, likely pushing the lower of the two deep through the ground plane which is probably what the design standards pushing for a single pipe were aiming to avoid. In more recent years, we've had some flattened pipes which allow for more intense packages and also potential flat floor aero, but way beyond the scope of a 20 year old X-type I'm afraid!!

What I've modelled so far is continuing the same 57OD as the existing Y-piece which is also what X200/250/350/351 with the same V6, but, I think that also has a lot to do with having a common-ish cold end with V8s. The other thing really striking me is how nasty the pressed 'banjo' looking outlet is, especially on the front cat (LH bank) which can't be doing it any good at all. If money was no option, and performance the goal, I imagine a smaller 'sports' cat would be an option that could more easily resolve the outlet into a 90deg radius bend instead of a frying pan!!

On the exhaust, I think whatever I am able to do though will be an improvement, but I have to remember ultimately my goal is to swap the 2.5 for a 3.0, I just can't bring myself to pay for that vile original Y-piece so I can definitely do something better, but getting into really unlocking things like the catalyst package constrictions or getting the double pipe all the way back to rear subframe is realistically out of scope. I'm open to reducing the diameter on the pipes between the cats (which are dia57 at their outlets) and the new Y-piece which will probably have to be at the prop centre bearing. I can't share the images of what I've drawn for the exhaust for fear of getting the sack.

On the airbox, I've found a lot of evidence after doing a bit of 'carcheology' since I first wrote on here that goes along with your helpful insights on the development including 3.0 and 3.2 GDI and multiple attempts at the AJ67, I can also see several companies which I probably can't say on here. Weirdly all the data associated with the third intake feeds seems to be deleted and the CAD proposals only preserve the carryover elements of the designs, one concept even refers to as 'Alfa-type', but key bit is missing in everything I've found. There's probably some 'jlr' generic numbers rather than proper DS's, but I've come up with my own anyway, accepting a flexible hose, which is just as well because I haven't figured where I'm going to take the extra air from, whether that's to the RHS of the two intakes already above the rad, or whether to pull from a void of cooler air somewhere. The key bit is this however:



^the nozzle itself is an FDM RP part but to resist shearing of layers there's some steel rod inserts running perpendicular to the layer lines

I was thinking about the throttle whilst cleaning mine up the other day and thinking it seemed quite paltry and hardly larger than the one on my MGF (1.8 K-series, the Rover, not the Honda for our American friends ). For the NASP vs SC running gear, from what I can tell the transfer case was changed between the two, but potentially more to do with the 'R' running 6 speed M66 trans (I think with a Volvo p/n from what I saw) rather than the 5 cog MTX-75

As for your own project, it's great to have someone with a connection to the car putting so much love into one. Even within the business there are a lot of people that don't really know what went into the car and buying the outside view of it as 'just a rebadged Mondeo' which is kind of offensive to those who did put their hearts and souls into the real car and don't realise how much is unique or at least uniquely tuned to the Jag. For the grief we got, it may as well have been, and probably still performed as well in the market... The two shared an architecture which is just plain good engineering across an automotive firm, and lateral sharing of 'right-sized' platforms within an architecture works better than trying to make a the same platform work in three-wheelbases which is not truly scalable architecture, it's three lengths of the same platform which means you're always compromised at one or both extremes whether that's cost, weight, performance, size, aero etc etc, and we now can see the 'big-three' German OEMs doing largely the same thing on their sub-compact execs (A3, A-Class and 1 series including saloon variants) that are now as larger or larger than the D-segment compact execs were at the turn of the century in terms of platform sharing across their businesses or joint ventures and all three being transverse.

If it's OK Count, I will drop you a private message to pick your brains on a couple of things that can't really be said in the open!

 

Just .2c about PCMs:
Pre-2006 X350, X200 had a Denso SH7055 based PCMs, 32bit, 512k flash size
2006-up ones had a Denso SH7058 based PCMs, 32bit, 1024k flash size (same as X150/X250)
All X400 had only SH7055 ones.
Besides a different connectors SH7058 is torque based PCM (7055 is still more airflow than torque). Also the flashing routines of that two types are pretty different.