Hello everyone,

I'm looking for advice from owners of Jaguar 420's (NOT 420G). I'm in the process of converting my MK2 (which has an XJ6 4.2 engine fitted) to power steering, using original re-sealed Burman steering box and associated links etc. My original plan was to utilise a Vauxhall Astra electric pump/reservoir ( as with the Wilkinson rack conversion) mounted on the nearside inner wing. It then occurred to me that the 420's used a fan belt driven pump mounted near to the distributor (as with the XJ6). Looking at the 420 parts manual it appears that the right-hand front engine mount incorporates the bracket for the said pump (Part No C26760 - which is no longer available new). My thoughts, therefore, have now gone towards using that set-up instead (if I can locate a used mount bracket ?). I'm a little concerned though as to whether the 420 has more available space in that area than a MK2 - the brake servo intrudes into the engine bay right next to the pump/distributor area. Is that also the case with the 420. No problem is un surmountable if space is a problem I suppose - I could possibly re-locate the servo. My request for advice, therefore, is twofold - firstly can anyone say what space is available on their 420 ( a photo would be a great help ?) and secondly, does anyone have a right hand front mounting bracket (incorporating the pump bracket) that I could purchase ??

Thanks everyone for taking the time to read my post. Regards Keith

 

I recently purchased a 1983 4.2 XJ-6 motor complete with everything. I am going to transplant it to my 3.8 S type.

I will be selling the complete power steering assembly, including the pivoting bracket assembly, the pump, the hoses, and the bracket-to-block mounting bolts.

I understand the 420 engine compartment is larger and can accomodate the XJ-6 pump, my S type forms a "v" shape like the MK-2 and unfortunately there is no room for the XJ-6 pump assembly. I do not know if there is interference with the brake booster.
others will comment as to available space or other issues if any.

if you are interested in the complete assembly, send me a PM.

 

Hello again Jose,

I think you're right - space is the problem (which is probably why the likes of Wilkinsons use the Vauxhall/GM electric pump). It's a shame because if it were possible to use the 420/XJ6 pump then it would entail shorter hoses between the pump and steering box (at least on my right-hand drive car). Thanks for the offer of your XJ set-up but it looks like I will probably stick with the Vauxhall pump (I've already adapted the bracket for it - see attached picture). As you intend putting the 4.2 engine into your car I've also attached a picture of my 4.2 engine in situ and another of the upright oil filter assembly which you may want fit (as fitted to S2 XJ's).

Kind regards - Keith (CaptainQ)

 

I am going to fit the 3.8 oil filter head to the 4.2, which sits at an angle and downwards in the S type. After all, it is the same block.

What exactly did you do to connect the tachometer to the 4.2 ? The 4.2 does not have a tach generator like the 3.8.

Also I am being advised to use the XJ-6 electronic distributor.

At least in my 1984 XJ-6, the distributor has been reliable since 1989 when I purchased the car, I have replaced the cap once in all these years, nothing else has been done to it.

Since you have already done the conversion to a 4.2, I would appreciate your experience doing it.

 

We have a saying in the UK - "There's more than one way to skin a cat !" (Sounds cruel to me - I love cats !). With regards the oil filter housing, the reason I used the S2 XJ version is that I can use a more modern spin-off oil filter. But I suppose you're quite right, why not use an angled MK2 version if you have one to hand (I know that the S2 XJ upright types are quite hard to find now anyway). I've attached a section of the 420 wiring diagram which shows the connections to the tachometer - there are only three wires to connect. It's certainly a less expensive route than having your S3 cylinder head machined, the cam cover replaced with an earlier version and replacing the inlet camshaft with one that's already drilled (or getting yours drilled/tapped). Obviously you will lose your fitted time clock (unless you can find a way to alter the 420 tachometer to accept it ?). I didn't have an electronic S3 distributor to hand when I did my rebuild but, if you have the required parts, then give it a go (I used a New Old Stock S2 XJ 4.2 distributor with old fashioned points).

Good luck.

 

 

Thanks for the image. Are you saying the S type / MK-2 tachometer cannot be rewired to work with the 4.2 engine as it is? I certainly do not want to have the camshaft reworked for a generator.

Another poster in AU tells me that I need a different intake manifold to use in the 4.2.

Were you able to transfer the intake manifold from your original engine to the 4.2 or did you have to get a different manifold?

 

Hi again,

The tachometer (rev counter) for an S Type/MK2 is a slef-contained circuit (see attached MK2 wiring diagram). It has only two wires going to it (as opposed to the three on a 420/XJ). The 420/XJ tacho works on pulses eminating from the ignition circuit. On that basis I do not think it's possible to use the S Type/MK2 tacho without the camshaft-driven generator.
With regards the intake manifold, I used twin 2" HD8 carburettors from a 2.8 Series 1 XJ (same as 4.2 except for needles) together with the manifold from that car - bolts straight onto the Series 3 XJ head. Whether the Series 3 3.4 XJ
manifold (later type SU carbs) would be usable with earlier type carbs I don't know (perhaps that's what the other member was thinking of ??)