The body design is fine, except for a hood louvers, A MUST ! Another priority is a vent to bring outside air into the cabin . Other than that there's just not enough room to list all the engineering blunders Jaguar "engineers" made on this engine, starting with the idling and cooling system and ending with the IRS and 10 bolt Dana.
Lawrence

 

There are no engineering faults on these old Jags. Anything that appears to be an engineering fault is really just "an interesting design feature".



Cheers
DD

 

What's wrong with the IRS?

 

I think that the modern incarnation of the XJS as a high-performance GT in Coupe or Convertible form is the 5.0 supercharged runout version of the XKR-S.

Therefore, I'm thinking more about all the improvements that were quite feasible and could have happened by the end of the XJS life in 1996 if Jaguar had felt that it was profitable to do so. So, in no particular order:

- compulsory fitment of ZF manual gearboxes on both 4 litre & 6 litre models
- AJ16 supercharged engine fitted in 4 litre models
- lower hood stack when lowered
- separate rear window switches
- cupholders in front part of centre armrest (as fitted on x300)
- standard heated, lumbar adjustment & height adjustable front seats
- straight-through centre exhaust pipes on all models
- compulsory sports suspension on all models
- ability for front centre vents to blow hot air
- twin lights inside the standard ovoid glass units

All possible, all desirable & many already fitted by some owners!

Paul

 

When the XK8 first came out I hated it, specifically as compared to my XJS. However, as time went by, I started to change my attitude towards that model, I guess that I started to look at it for what it was on its own, rather than super imposing my XJS over it and I came to realize
how superior the car really was over the XJS, as a machine in every aspect. And that big wood veneered dash is the best I've ever seen, including Rolls and Bentleys. Then, the so-so later XK design makes those early XK8's look even better. I wouldn't mind to own one along with my XJS, but hey! The XJS would always be the boss around here.

Cheers,

 

Grant remember that Sad Picture I sent of the Radiator Cap off my Merc, I've just found something even Sadder than that!

So get the JD ready and prepare to fall off the Wagon (I'll PM you a Pic.)

 

Hi Paul

I've found plenty of X300 Armrests but they don't appear to have any Cup Holders in?

 

Hi Greg

Are you saying that you can get an Aston Head to fit on the existing V12 power plant?

If so what sort of money are we talking about and what sort of figures (approx) for HP 0-60 and Top Speed?

 

Alan, concentrate! I am saying that two cylinder heads from a Jaguar AJ6 engine, as fitted to all 3.6 litre XJS and other Jaguar saloon cars, will fit straight onto the Jaguar 5.3 litre V12, PROVIDED one of the heads is cut and welded to get the cam drive and the exhaust and intake in the right place, and various other mods that need to be done such as cam drive chains, pistons, etc etc. Hence big money.
But is has been done and the thing makes huge power, because, and only because, the cylinder head on the AJ6 is a far better design, having 4 valves per cylinder, a far better combustion chamber shape, and better induction manifolding etc etc.
I am not repeat not, recommending any Aston bits whatsoever. Just mentioning that the Aston V12 is a good engine because it shares much design similarity with the AJ6 - as does just about every other modern petrol engine with 4 valves per cylinder, twin cams and a pentroof combustion chamber - which is most of them including the Ford Zetec 4 cylionder twin cam and the Ford 2.5 litre V6! This configuration could easily make 450 BHP in an ordinary road-going state of tune.
We are talking 50 or 60 thou GBP possibly 100, plus shipping from Oz, plus somehow getting it into the XJS - hence my desire to re-engineer the front end!
Greg

 

IRS ?? First off for the guy that don't fully work on his XJ-S (not me)! Every try to get the inboard brakes worked on, shop to do it, $price$. Don't forget these cars are over 20 years old, how many Jaguar tech's still work @ the dealer that remember inboard brakes. Second, I THINK or @ least this can be made into a semi hi performance sports car via 5sp, gearing, engine mods, whatever, for this person that likes to "bang a shift", "see what it will do", etc . Yes the four rubber mounts are a weak point. Ten bolt diff's in the XJ-S vs a 12 bolt ,9in Ford, type etc, in a hi horse/torque sense has is no argument at all. Even though a "?few know of 700HP? XJ=S's that hold up fine.......
IMOP the stock Jaguar IRS is designed and meant for the "Blvd Cruiser" type ready to pay big buck for inboard brake work. Driven NORMALLY in acceptable weather the well maintained STOCK IRS & 10 bolt will probably last a long time. A little off the subject, just my answer/opinion to a question
Lawrence

 

Hi Greg

Got it now!

Just a bit over excited at the prospect of an Aston Martin-esq powered XJS.

It sounds like it would be cheaper to take a V12 out of a 'Scrap Aston' and go from there.

 

Rear disks rarely need replacement, but even then it's not particularly difficult or time consuming to do, compared to outboard brakes. Only key piece of equipment is a frame type hoist, but any major shop will have that.

Replacing rear pads is no more difficult than any other car.

 

I think the electronics part would be much more difficult than the mechanical part of doing an engine swap. Depends upon how integrated the Aston's electronics are with the rest of the car.

 

JDM Import Aston Martin 5 9 V12 Vanquish Complete Motor Transmission 2001 2005 | eBay
engine and trans with a booboo manifold.... cpu's too
lots of pictures


it looks better undressed
?dap Aston Martin 2012 DBS 6 0L V12 Motor Engine Block and Heads 4G4E 6015 Ad 1 | eBay

it will fit... just look here... have a bucket ready for those with weak stomachs...
http://jalopnik.com/5819712/your-cha...-aston-martin/

 

OB,

You could get them with or without the cupholder section. Fit straight on an XJS with some modification to catch, I believe. I think the same applies to x308 cupholder armrests. Jaguar even have some of them in limited colours new.

Paul

 

Thanks for posting that, very interesting and it doesn't seem too expensive in the Scheme of things, although I wouldn't know where to start with putting that in.

So as for me I would probably be best to stay with the Engine that I have got.

Though if I ever win the Lottery, then who knows. anything is possible providing you've got enough Cash.

 

Hi Paul

It looks as though I've been finding the ones without Cup Holders, although I did see a new one for over £100!

Maybe I'd better have a look round the Scrapyards.

 

I believe all the X300's in North America came with the cupholder armrest as standard. The mechanism was fairly flimsy, most are broken. That usually means the cupholder part stays open, and won't stay in the latched position. Jaguar did make a repair kit for them.

 

A great deal cheaper to buy an Aston V12!
Greg

 

No good criticising the XJS for not being a Corvette or an muscle car. What you call a boulevard cruiser I call a Grand Tourer, built to do 400 or 500 fast miles in a day and leave the two glamourous occupants feeling fresh, GREAT, comfortable and ready to do it all again the next day!


Ditto the axle, when the car was launched, the best rear axle in the world for that combination of roadholding, grip, comfort, ride, NVH suppression. I agree the "modern dream XJS" of the thread would have something more modern (see my post, for example) but I think to knock the original for not being what it was not intended to be, and not serviced any more by the main dealer is a bit unfair.
Greg