Hello! Newbie here with 6 litre XJ12

[oversteerxj12]

Hi fellow jag lovers, I'm a new member and have a 1993 XJ12 which I've had moth-balled nearly 4 years and am finally throwing some money at to get how I want her.
She is wearing Aston Martin DB7 wheels and I have just ordered GAZ adjustable front shocks and custom made height adjustable rear shocks.
I am lowering the car around 75mm and am currently rebuilding the front suspension with superflex poly wishbone bushes and new drop-links and roll bar bushes.
I'm cleaning everything up and painting as I go.
Rear end just needs A-frame bushes, has anyone got any experience of changing these? I take it I will need a special tool to press them out and in?
Engine wise I am taking the heads off to re-grind the valves and replace the stem seals. I'm also fitting a new timing chain while I'm at it. Any tips or advice on this?
I have a full stainless TT extractor exhaust system on its way from AJ6 Engineering, together with free-flow air-filters and a chip to get the fuelling right. Anyone have any experience of these mods on the V12?
I've also installed matching leather late XJS front seats mounted on the XJ12 frames with all the electrics connected and working, so now I feel like I'm sat IN it rather than ON it, and have a nice old school MOMO wheel to replace the huge old bus wheel.
This little lot should see her on the road, legal, driving like a dream with around 360bhp, the next stage will be getting her painted as she has the usual XJ40 bubbles here and there and a totaly knackered tailgate.

Just thought I'd share my enthusiasm with u all and any answers to my queeries would be well appreciated!

Edited by oversteerxj12 on Friday 24th October 11:34

[x200sxy]

Think the AM wheels look great on the XJ40. Superb looking car.

[exgtt]

Thats a lovely looking motor mate. These things have a coolness on par with MK1 Golfs when done right like yours.

Out of interest where did you buy the shocks and springs from? Theres 4 shocks on the back right?

Ps watch your sump! I would imaging that v12 being quite close to the ground!!

Edited by exgtt on Thursday 18th September 14:29

[oversteerxj12]

Cheers mate, I'd argue cooler than mk1 golfs with 6 litres, 12 cylinders and rear wheel drive but I catch your drift
There are only two shocks on the back of XJ40s, a change from previous Jags IRS along with the rear discs changing from inboard to outboard due to excess heat and being a nightmare to service.
The shocks are direct from GAZ, with the rears having to be custom made with height adjustable spring platforms.

P.s. As regards the sump I learnt from experience after ripping open the sump on my old E30 BMW lowered 4". Yes honestly, 4"!

Edited by oversteerxj12 on Friday 19th September 18:42

[Kieran XJR]

That's a great looking forty, like that!

I'm going to do a rebuild on my suspension soon, thinking of using Superflex bushes, what does it ride like on those?

[oversteerxj12]

Kieran XJR said:

That's a great looking forty, like that!

I'm going to do a rebuild on my suspension soon, thinking of using Superflex bushes, what does it ride like on those?

To be honest I don't know yet!
It's not been on the road (legally!) for 3 years and needs all this work for it's MOT.
Will hopefully be sorted in 2-3 weeks now depending how the engine rebuild goes.
Problem is that I have no garage so I'm doing all this in the street and am somewhat dependent on the weather!
Will keep you posted tho.

[WDRV12]

oversteerxj12 said:

Engine wise I am taking the heads off to re-grind the valves and replace the stem seals. I'm also fitting a new timing chain while I'm at it. Any tips or advice on this?
I have a full stainless TT extractor exhaust system on its way from AJ6 Engineering, together with free-flow air-filters and a chip to get the fuelling right. Anyone have any experience of these mods on the V12?

Edited by oversteerxj12 on Monday 15th September 13:21

Yes loads of experience on these, If your taking off the heads then you may need a "head tool" to pull them off. A few people have these for sale or loan . Dont try using crow bars or such like you will "kill the machined faces" while the heads are off take time to port match the manifolds ,both inlet and exhaust, its worth every penny and minute you spend. Larger throttles are simple to change and give a much better response etc TT exhaust are good but if you can stretched to the cost of tubular manifolds then thats where you'll find better power. Timing chain can only really be done when the heads and sump are off and change the front crank seal whilst the covers off. Timing and tappett clearances are a must to get right if you want any power from it and are a good reason why "old " V12's run badley and become thirsty !!

[oversteerxj12]

WDRV12 said:

oversteerxj12 said:

Engine wise I am taking the heads off to re-grind the valves and replace the stem seals. I'm also fitting a new timing chain while I'm at it. Any tips or advice on this?
I have a full stainless TT extractor exhaust system on its way from AJ6 Engineering, together with free-flow air-filters and a chip to get the fuelling right. Anyone have any experience of these mods on the V12?

Edited by oversteerxj12 on Monday 15th September 13:21

Yes loads of experience on these, If your taking off the heads then you may need a "head tool" to pull them off. A few people have these for sale or loan . Dont try using crow bars or such like you will "kill the machined faces" while the heads are off take time to port match the manifolds ,both inlet and exhaust, its worth every penny and minute you spend. Larger throttles are simple to change and give a much better response etc TT exhaust are good but if you can stretched to the cost of tubular manifolds then thats where you'll find better power. Timing chain can only really be done when the heads and sump are off and change the front crank seal whilst the covers off. Timing and tappett clearances are a must to get right if you want any power from it and are a good reason why "old " V12's run badley and become thirsty !!

Good advice, thanks!
Unfortunately I can't stretch to tubular manifolds much as I would love to, it might not seem like a car to run on a budget but seriously I am doing this on a shoestring!
I have considered larger throttles and probably will go down that route when funds allow, it's not quite as straightforward on the XJ40 as on the XJS though, as there are restrictive elbows between the air-boxes and throttle bodies which I would have to remake in a larger diameter to get the most from bigger throttles. One for the future though.
Definitely will be looking into port matching and, of course, re-shimming the tappets. Are tappet shims a dealer only part or do you know of any decent independent suppliers for bits like these?
Also, If I can get the heads off cleanly is there any need to skim them? It's not been overheated and nothing leaks as is. If so, how much can/should be taken off the heads and is upping the CR by much worthwhile?
Many thanks in advance!

[300bhp/ton]

Love the V12's. Had a 5.3 XJS myself and my Dad had a 1993 XJ12.

They sound great with a sporty exhaust.

I'd be tempted to look at getting parts made, either yourself or custom for the intake. The stock airboxes aren't very good. A decent cold air induction kit is what you want.

And I agree about the TB comment.

You can buy pretty much any tubing and bends you need from places like this. As well as decent cone filters: http://www.merlinmotorsport.co.uk/SAMCO-HOSE-&...

Top hat plates for TB's are available online as well if you need them.

[oversteerxj12]

300bhp/ton said:

Love the V12's. Had a 5.3 XJS myself and my Dad had a 1993 XJ12.

They sound great with a sporty exhaust.

I'd be tempted to look at getting parts made, either yourself or custom for the intake. The stock airboxes aren't very good. A decent cold air induction kit is what you want.

And I agree about the TB comment.

You can buy pretty much any tubing and bends you need from places like this. As well as decent cone filters: http://www.merlinmotorsport.co.uk/SAMCO-HOSE-&...

Top hat plates for TB's are available online as well if you need them.

Cheers for the link.
I have plenty of plans in the pipeline for this car but just want to get it legal and running properly for starters. Problem with cone filters is drawing hot air from the engine bay, which does get rather hot in these cars! I will probably holesaw an additional inlet into the airbox drawing cold air via tubing from down by the fog light area, then look into bigger elbows and enlarged throttles.
I seem to have a fair amount of the car now sat in various rooms of my house and heaps of shiny new bits just waiting to go on! Am picking up my exhausts tommorow too, can't wait!
Once there are a few bits back on the car I will post some pics showing progress.

[300bhp/ton]

oversteerxj12 said:

300bhp/ton said:

Love the V12's. Had a 5.3 XJS myself and my Dad had a 1993 XJ12.

They sound great with a sporty exhaust.

I'd be tempted to look at getting parts made, either yourself or custom for the intake. The stock airboxes aren't very good. A decent cold air induction kit is what you want.

And I agree about the TB comment.

You can buy pretty much any tubing and bends you need from places like this. As well as decent cone filters: http://www.merlinmotorsport.co.uk/SAMCO-HOSE-&...

Top hat plates for TB's are available online as well if you need them.

Cheers for the link.
I have plenty of plans in the pipeline for this car but just want to get it legal and running properly for starters. Problem with cone filters is drawing hot air from the engine bay, which does get rather hot in these cars! I will probably holesaw an additional inlet into the airbox drawing cold air via tubing from down by the fog light area, then look into bigger elbows and enlarged throttles.
I seem to have a fair amount of the car now sat in various rooms of my house and heaps of shiny new bits just waiting to go on! Am picking up my exhausts tommorow too, can't wait!
Once there are a few bits back on the car I will post some pics showing progress.

cool pics are always good

On the airbox front, I can't remember what the 6.0 litre used. The 5.3 had tiny little airboxes bolted to the TB. The used small panel filters and the inlet trumpet was way too small.

In fact, the XJS airboxes were actually the ones from a 2.0 litre TR7 making 105bhp, so it shows how restrictive they are.

Some decent cone filters, and a nice big bore section of tubing would make quite a difference. Yes under bonnet temps climb, but once moving they are no where near as bad. You may be able to to fab up some ducting from infront of the rad.

A pair of these would work well: http://www.knfilters.com/universal/apollo.htm

Locate the filter & filter housing as far forward as you can. Run the ducting tube to the front of the car and buy a length of silicon hosing and a 90 degree aluminium elbow joint to attach to the TB. For the crank case breathers you could plumb them into the filter housing or use "to-atmosphere" mini filters.

[groomi]

For a really hardcore look, you could lose of the inner headlights and pop the filter just behind.

[oversteerxj12]

groomi said:

For a really hardcore look, you could lose of the inner headlights and pop the filter just behind.

Yeah, I had considered that, would certainly look cool and work well.
I just have too much to do and no time and am so keen to just get it running and usable!
I have got a pair of K+N panel filters for the original boxes which, I am assured with additional cold air ducting, should flow well enough for 400bhp.
After that I believe the way that the exhaust valves are recessed into the head on the HE engine becomes the most restrictive factor so everything else is pointless without head work.

On the headlight front, the bowls of the lights are rather corroded needing replacement. I am toying with sticking in a set of lights I have from an early nineties 7 series beemer with the projector stylee smiley face things, might look cool and a bit different!

I got my exhausts today as planned, mmm shiny metal bits! Lovely quality so hope it all fits well.
I also opted for a 'Super enhanced ECU' off AJ6 engineering seeing as though they were burning me a new chip to suit the new exhaust anyway. Should make for a pretty quick motor with about 365bhp and a very fat torque curve.

I've also refurbished all the wheels now, stripped/primed/painted inside and out with new tyres and re-balanced.

I've also stripped the front suspension and have started grinding up, priming and hammeriting the ARB and wishbones.

I had originaly gone down the route of adjustable spring seats with standard springs but it was just too soggy and the spring plates were sat too low off the wishbones so I am going to have to get springs custom made, prob 20% stiffer and around 50mm lower than standard.
Ordering them tommorow me-thinks.

Pics to follow soon!

Edited by oversteerxj12 on Saturday 11th October 00:20