Hello people.

I am new here. found this forum while researching supercharged v12s. i own a S2 XJ12L and am looking at supercharging the beast. I am thinking of ditching the standard efi and go aftermarket with fuel & spark. also want around 7 litres and single or dual superchargers. will be putting a turbo400 in, mine is the model 12. also wondering if anyone is running serious horsepower & torque as occassional drag runs will be required. So I am tossing the idea of the 9inch centre conversion, but would prefer to stay all jaguar if its tough enough. Ive already done a big block chevy series 3 previously and it was a beast, just not very refined. so a potent ***** is what ild like this time round. Any technical info, suppliers etc would be greatly appreciated as this should be finished in the next year or 2 and im keen to get started. With a supercharged engine I would like to get around 6-700 horsepower if its possible. also very interested in raceheads if there are any in existance for sale ie broadspeed,twr group44 things like that.

Many thanks...

 

Well after a couple of days it seems there aren't any v12 experts out there. Sorry to hear it. Have fun jag owners and I will work it out myself coz I'm a ***** lover( jaguars of course)

 

Kirby Palm stuck 2 on his XJ-S, the same guy who wrote "Experience In A Book" Help for the XJ-S Owner. There was a picture of it on Jag-Lovers, but the site is down or something. He lives in Florida USA, maybe you can track him down.

 

There are a number of V-12 experts on the board. Some of them hail from Australia.

They just may not be interested in aftermarket SC applications.

The lack of interest in no way diminishes their expertise.

 

Thankyou for the responses, I have contacted v12 sales( no response yet for nearly 3 weeks)and Rob Beere in uk. Ron seems to be the man of knowledge and parts, although didn't realize that a potent kitty could cost$30k 7.4l race spec 650hp 700lbft

 

Sorry 600ftlbs
Does anyone know of all 6l cranks are forged or cast

 

Hi Dad,

You will find more interest if you post in the tech section for your model.
You might also be interested in the twin screw discussion that is going on in the X308 section.
I don't believe we have seen you in the new members intro section yet?

 

6.0L cranks came both ways,, early were forged ,, later cast.

but remember FORD knows a lot about cast cranks,, easily handle 600hp.

 

i may as well toss this in, I'd go twin turbo,, not engine drive S/C.

remote mount twin turbs. very doable.

 

Daddycool454

Big Block I think that teddykan or tedykan in South Africa on Jag-lover might be able to help, and Kirby Palm who hung 2, one on each bank and uses his as a daily driver might be able to help you out. Like ronbros, I've been thinking twin turbo's for myself.

I wish I could rememberwhat brand of SC's Kirby was using, and if I can ever get back on Jag-lovers I'll let you know.

Bill

'83 XJ-S

 

How have you progressed with your build? If you are interested I have a few ideas on SC the V12. Where in Sydney do you live?

The Broadspeed heads were flat heads with combustion chambers machined into them. There is a guy in Melbourne Norman from the E Type Factory who know a lot about high performance V12's

 

You're probably thinking of Bradley Smith's XJS:

Bradley Smith XJS in Detail

He passed away a few years ago. The car comes up on Ebay now and again

Cheers
DD

 

Bradley used twin whipple superchargers, I love PD blowers BUT I think on the XJS this would prove impossible to get traction without drag radials.

Lister used twin Albrex centrifugal SC's - this is my preference - after 2 years of research. The XJS V12 is a very torquey engine

 

I've got 6L and 7L TWR blocks, with forged TWR cranks, big valve heads, competition valve spring kits, long duration cams, IMSA magnesium throttle bodies, etc etc...get in touch if deadly serious....

 

Hello everyone, well just got married this weekend past, so after I finish paying for it, probably feb next year I can get started. I haven't done anything yet as I promised my wife to be I wouldn't start until after the wedding. Anyway that's done and I have spoken to a couple of people. Recently went to motorex

 

And saw some awesome cars but no jaguars. Looks like I might have to increase the excitement here in Sydney of a potent kitty. Will keep you all informed as I get started. Looking at the kenne bell as a potential supercharger also, although that will require a significant induction system...

 

You're in Sydney, have you not seen the Twin-Turbo XJS from Bruce at Jagworks?

1977 JAGUAR XJS V12 TWIN TURBO Race car - CAMS LOG BOOK - JAGworks#

 

I have this 6.0L V12 to go in the XJS next year



I plan to use a CF supercharger where the PS pump is, and install an MR2 electric PS pump

 

I have had the opportunity to get under and in this beast. Bruce was nice enough to put it on the hoist so I could have a good look underneath. It is currently running a 5.3L with twin t03 turbos and would you believe a STOCK radiator. No overheating issues even at full tilt around Mt Panorama.

I last saw this running at the super sprint a couple of months ago and it sounds AWSOME.

 

7L will require either 84mm stroke crank and 93.5mm bore 6.9L, 93.5 is max overbore on stock liners. You can offset grind the crank and use chev small journal rods this should give you close to 84mm stroke.

I wll have my Jag TH400 available next year if you are interested. I have a 4l60e to go in. Although your block bolt pattern is different so will require the block to be re-drilled.

The stock Jag diff will be fine Bruce is running the stock diff in the TT XJS. I also have an assortment of ratios, I am not using. Be careful going too low - when Gary Walker build the first XJS TT his had 3.07 and this was too low he ended up with 2.88's, he said even with 285 rear tyres it would smoke the rears easily.

500hp is not too hard on the flat head engines but go further and be prepared to $$$$$$$$$$$$$. You can get bigger valves in the flat head engines easily - BUT the exhaust valve is quite shrouded by the cylinder wall (opposite to the SBC). A bore increase helps.

The

The 6.0L is good for 450hp NA so SC should be ok for 500-600 I expect more like 550hp. Where the V12 shines is the AWSOME spread of torque