XJ Coupe with a supercharged 6?

[HaylingJag]

Men of infinite wisdom,

whilst waiting for my 77 XJ Coupe to have its new undercarriage sorted, sills & floors etc, i have been pondering over the possibility of fitting a 6 cyl S/C engine and box. Now dont get me wrong, i know the 4.2 xk is a good motor but the thought of 300+ horsepower up front in the coupe is enticing.
Probably spurred on by the Mk11 Beachams V8sc as seen at Goodwood this year!

Interested if anyone has any info on the install, has done it themselves to a Coupe or Saloon, and was it indeed worth the time/money invested. I understand that there are a lot of opinions on "modernising" and i am keen to hear all sides of the debate.

For info i do have a donor vehicle available with strong mechanicals if needed, and once in the Coupe it would become a long term keeper. Also, what thoughts would you have on long term investment values if the drivetrain deviates from standard.

cheers
Darren

[Spitbarnatt]

I may be wrong but if you look at the V8sc MK II's it looks like they use everything from the x308. Not just the engine and box, but the whole centre console and even the steering wheel and column/ switchgear. To be honest that is probably easier if you have a complete doner car than trying to get the engine and gearbox working on an aftermarket ECU. There was a thread somewhere with someone putting a 6cyl sc into a series 1 xj saloon. I think it was on retro rides or turbosport. Personally it is a project I would love to do myself, I even have a lwb s2 Daimler and I did have a running XJR8 but I'd never have the time so I sold the XJR.

[XJ Flyer]

Depending on the budget a 6 litre V12 from an XJ40 with some tuning mods maybe including a big bore liner kit taking it to 6.8 and 5 speed Getrag would probably suit the character of the car better and be quicker too.

[Swoxy]

Wow. Please do it.

[a8hex]

I've seen an XJ-Coupe which was being fitted with the engine from the XJ40.
I asked why the owner wasn't doing the obvious thing and going for the SC AJ26, but apparently the project had started that long ago they'd not been so easy to find. It does sound an interesting proposition.
There's a D-Type rep which has been showing up in the Mags for sale for years that has SC AJ26, in a sub 1 ton car that has got to be interesting.

[HaylingJag]

Spitbarnatt said:

I may be wrong but if you look at the V8sc MK II's it looks like they use everything from the x308. Not just the engine and box, but the whole centre console and even the steering wheel and column/ switchgear. To be honest that is probably easier if you have a complete doner car than trying to get the engine and gearbox working on an aftermarket ECU. There was a thread somewhere with someone putting a 6cyl sc into a series 1 xj saloon. I think it was on retro rides or turbosport. Personally it is a project I would love to do myself, I even have a lwb s2 Daimler and I did have a running XJR8 but I'd never have the time so I sold the XJR.

True, i have studied the MkII in detail and had a good chat with Dave, the owner of the former Patrick Head example. I too was thinking of at least the centre console and steering column invading the interior although retaining the characterful dash of the Series 2. I have a full running XJR-6 to call on though i also feel that it would be sacrilegious to rob this of life to achieve the Coupe dream.

D

[HaylingJag]

XJ Flyer said:

Depending on the budget a 6 litre V12 from an XJ40 with some tuning mods maybe including a big bore liner kit taking it to 6.8 and 5 speed Getrag would probably suit the character of the car better and be quicker too.

Broadspeed replica would be nice too. but as i have the "donor" vehicle, which owes me nowt, then i think i could get this done on a relatively modest budget. i also like the idea of a sober looking sleeper

D

[BDF!]

XJR swap were already done to E-Type, XJ and XJS. Not an easy job they say.

E-Type with XJR engine

http://www.patsetypes.co.uk/

The XJR serie I was looking for is here http://www.driftworks.com/forum/drift-car-projects...


Here is an XJS-XJR for sale (for long) in US


http://www.ebay.com/itm/SUPERCHARGED-JAGUAR-XJS-CO...

Also in an XK

http://www.jaguarforums.com/forum/xj-x300-xjr-26/x...

Edited by BDF! on Wednesday 8th January 21:52

[HaylingJag]

nice one BDF, this is what i was looking for. That installation in the XK looks so right.

thanks for the legwork, im going reading

[tortop45]

I all so have an xj coupe so congratulations to you,regarding its classic value when modifing it well youve just got to look at prices of other modified cars out there for sale,as i see it yes it will devalue your car and will make it harder to sell later on down the road.there was one on ebay with the wrong engine in it about 2-3 months ago it didnt sell.But saying that ive fitted a 4 speed manual gearbox into my daimlar doublesix coupe which came out of an xjs of the same era,coz its what i wanted so if thats want you want just do it .

[QuiteQuietCerb]

a mate of mine has been considering this for his 77 coupe as his engine seized. However, he's gone down the route of a 4.2 injected from a series 3 car. It gives about 200 brake and with a few mods it cam go to up to 230-240. It will suit the car better i think that the s/c engine, unless you can bear the cost of all the mods in the engine bay, electronics, and brake/suspension upgrades. When we looked into it, we estimated about 6-7k for the work, vs about 1-2k including series 3 engine (second hand)

[XKRacer]

I just bought a X308 XJR to use as a donor, I only really want the engine and ancillaries, rads etc, the lot is going into an XJS with a manual box, should make an interesting car for the customer

[HaylingJag]

That's gonna be a nice car

Just ball park, but if both the xjc and the xjr were driven into your workshop what would be the cost of implant to the stage of driving away the xjc- supercharged?

Cheers
D

[richw_82]

Mine is the white series 1 XJ6 that pops up every now and again. Its currently got an AJ6 in it as I couldn't get my head around the X300 XJR's security and at the time my megasquirt knowledge was pretty poor.

The mechanical details are simple. The AJ16S bolts in using XJS 3.6 engine mounts. No cutting no welding no fuss! Wiring loom is either standalone, or you can pick apart the X300 item for the bits you need. Feed it into the cabin through the redundant hole for the steering column on the passenger side, power is fed off the crash/inertia switch.

Fuel system is XJ6 S3 4.2 injected, as you get all the correct fittings, and they go straight into a Coupe.

Whil my initial attempt came to nothing, co-operating with some other people has seen an XJ Series 1, and more recently a coupe fitted with the XJR engine, and I have the megasquirt files to run it. I'll be cracking on again with mine this summer, as a house move got in the way so the car's in storage..

Regards,

Rich

[HaylingJag]

Good info Rich, thank yu.

i have a mechanic local to be who is very good at the suoercharging and fuelling of Peugeots and he seems more than happy to take the job on if this is the way i want to go. Interestingly the, fuel supply from the series 3, is the twin tanks/pumps not "man" enough for the job or are they specifically there to supply carbs?

cheers
D

[richw_82]

The fuel tanks from the S3 are fitted with return lines and vents, and have a larger bore feed pipe for the Bosch fuel injection pump. It seemed to me there was no point reinventing the wheel to make a working fuel system for my S1 when Jaguar had already done the hard work for me!

The original SU pumps (or the in tank submerged pumps if you have a later S2) are capable of providing quite a lot of fuel, but not at enough pressure for fuel injection - and definitely not enough for the demands of a supercharged engine.

Edited by richw_82 on Monday 13th January 14:11

[andyps]

As the XJ coupe has the same basic chassis as the XK8/R would the V8 fit reasonably easily?

[BDF!]

richw_82 said:

The original SU pumps (or the in tank submerged pumps if you have a later S2) are capable of providing quite a lot of fuel, but not at enough pressure for fuel injection - and definitely not enough for the demands of a supercharged engine.

I doubt the XJ12 S3 fuel pump (not submerged) used to feed the hungry V12 will not be strong enough to feed the XJR.

andyps said:

As the XJ coupe has the same basic chassis as the XK8/R would the V8 fit reasonably easily?

Paul Banham tried to drop a Jag V8 in his XK180 replica prototype and it's said to fit.

[richw_82]

BDF! said:

I doubt the XJ12 S3 fuel pump (not submerged) used to feed the hungry V12 will not be strong enough to feed the XJR

The XJ12 S3 has the same Bosch injection pump as fitted on the S3 4.2 injection. There's no difference in fuel tanks, pump, filter or any of the plumbing in the boot.

If you tried the non-submerged pumps off a carbed V12, you still wouldn't maintain the fuel pressure.

[BDF!]

I have a carbed V12 XJ S1, Rich, 2 double fuel pumps are needed to feed the beast which uses to drink up to 8 MPG
I also have V12HE's XJS and XJ's, much sober but stil heavy drinkers. Same fuel pump was used on many European fuel injected cars at the period. How many MPG are supposed to be achieved with an XJR?

Edited by BDF! on Monday 13th January 19:54