My S-type is currently for sale as I’ve been offered another S-type which needs a lot of work but is worth saving. One of the things to address is no engine or gearbox.
I’m not precious about putting the ‘right’ engine in an am interested in a more modern power plant. It doesn’t have to be a 400bhp V8 beast, just something reliable and more modern.
In the UK the X300 XJ6 can be bought cheaply as many are rusty now, so one option might be a 3.2 6 cylinder and auto box.
Has anyone done a similar conversion or something else?

Regards,
Mark

 

The swap you propose has certainly been done in Mk2s so should be equally possible for your S. I was seriously considering it for my Mk2 and feel the AJ6/16 is an excellent choice. It's lighter and more powerful than the XK and is as tough as any engine there is. In the end, I decided against through fear of the UK DVLA removing the car's historic status - their rules are vague. I might also have been a little influenced by the loss of the XK cam covers.

No swap is easy. The first requirement of engineering design is to avoid two parts occupying the same space. That's not as trivial as it sounds and you will certainly be moving parts around. Then there are the mechanical connections, mounts and drive train. For the electronic control of the engine, it's probably easier to start from scratch with an aftermarket ECU rather than trying to transplant from the donor car. However, it's an extra cost to add in. If I remember correctly, the 4HP22 gearbox of the 3.2 X300 is mechanically controlled, which might make things easier than the electronic gearbox in the 4 litre.

In summary, there are a lot of things to think about and plan; there are difficulties, but the swap is possible.

 

That's a very good point, the AJ16 engine is wide at the bottom with accessories and the S Type engine bay isn't. Moving those around would take some fabrication, including belt tensioners. Space is limited and it's not easy. Yes, the 3.2 does have the mechanically controlled transmission.

I would be tempted to go with a 4.0 for reasons of the ECU. The European cars had immobilizers built into the ECU and Canada/USA cars (only) didn't. Not having to implement the security system makes the job much easier. However, Canada/USA only got the 4.0 cars, with the electronically controlled 4HP24 transmission, not the 3.2. If you're taking the wiring from a donor car for the engine ECU it's not difficult to keep the harnesses for the transmission ECU as well.

What was the transmission in the S Type originally? The transmission tunnel/floorpan of the S Type varies if the car was originally manual or automatic. The automatic of the original was wide and short relative to modern automatics, so you would likely have to modify the tunnel to get a 4HP24 to fit.There is a crossmember at the back, so it would take some metalwork to get it right.

Assuming the floorpan can accommodate it, if it was me I would get an XJ6 4.2 XK engine and a manual with overdrive transmission. Possibly use some sort of aftermarket EFI/engine management to give it modern drivability, but it would be a much simpler project. I would use a 4.2 because they are common (but look original), and have extra bosses on the block to add additional brackets. A 4.2 is less prone to detonate than a 3.8 as well. Then you could have an alternator and power steering ( and future air conditioning) much easier than using a 3.4 or 3.4 block, and it would be a bolt in to the car.

 

A 4.2 engine should fit into the s type engine bay which is pretty much the same dimensions as a MK2. The overall dimensions of the block are pretty much the same as 3.4/3.8.
The spin on oil filter and housing will not fit. You will need an earlier filter and housing off a 2.4,3.4 or 3.8 engine.
The 4.2 engine mounts and accessories will need to be removed and you will find that the holes left correspond to the earlier mount system as on your current S type.
You would also have to fiddle around with the front pulleys as the original crankshaft pulley on the 4.2 is too long to fit behind the radiator.
I would stick to carburettors as the EFI system on a series 3 XJ6 requires extra plumbing and sensors on the fuel system.
You can put carbies on a series 3 motor. A friend of mine was running triple carbies in a S3 XJ6. But dual 2-inch cabies off any 4.2 motor are adequate.
I would try to find a 4.2 motor with a manual overdrive box attached (which is far more likely in England) Most XJs imported to Australia were automatics.

 

There were some where the filter pointed straight up, those would work. My Daimler had one, and they were also used on some Series II XJ6. Part number EAC5802 for the Daimler, C44361 for the XJ6. Not what (if any) difference there is.

 

Having installed a GM aluminum block LS1 V8 I know first hand if you are determined even a wide big V8 will fit, but an easier option would be either the Toyota 2JZ or the Nissan RB twin cam straight 6 turbo engines would easily fit with room to spare and provide much more power and reliability than the XJ6. No matter what you install there will always be some custom fabrication so you might as well get decent power for all of that effort.

Here is a money no object 2JZ into the classic Jaguar to give you inspiration; it can be done without all the custom touches with far less money,
Both the 2jz and RB twin cam engines will easily put down 400-600 HP with very little work and be a reliable engine for many miles. The RB is easier to find in the UK vs the LS V8. For me in the US the LS V8 is inexpensive yet lighter than the stock engine and my engine is about 500 HP right now and a reliable daily driver.

 

There is a youtube channel called "BA in the garage" where the guy has a series of videos with a 1960's Jaguar S-Type where a previous owner started the installation of a AJ6 into the car. I don't think there was any major modification to the crossmember or frame structure of the car to accomplish this. I would urge the original poster of this thread to take a look at the video series to see more details of the conversion.

 

The easiest and cheapest route to a compact Jaguar is to buy an X-type. It's an excellent car, better than the contemporary BMW 3xx to drive, and extremely reliable. However, we don't do this stuff because it's easy. You have to decide what you want, originality, non-original but of the time, modern but Jaguar, an out and out blast, maintaining historic registration with the DVLA, ... ? What's the priority, doing the project or obtaining the final product? How much can you do and how much will you contract out? And, of course, what's the budget?

If you don't care about the engine, the V6 from a modern S type might be a nice choice. Are you set on an automatic? Modern electronically controlled boxes are wonderful, but the more recent they are the more they are integrated into the computer systems of the engine and the rest of the car. If you're not seriously into electronics, that becomes quite a big deal. Also non-Ford ZF boxes have their ECU internal to the box. The gearbox can require even more planning than the engine.

Regarding the 4.2 and its carburetion, twin SUs are the most convenient for fitting into the space. They are close to original and look great. Re-building them can become expensive. My inclination is to go to injection. Injectors can be fitted inside the SUs. Another, but more difficult to fit route is injection with a Weber type manifold or individual throttle bodies. The Series 3 XJ manifold fits if you turn it upside down. The final option, my preference, is make your own plenum and manifold.

 

When people here say "The Series 3 XJ manifold fits if you turn it upside down" does that mean just turning it upside down and bolting it on the head without any other modifications or does that mean cutting the runners off outside of the injectors, flipping the plenum and then welding it back on?

 

Steve, It means it's possible to turn it upside down and it will bolt on without interfering too much with parts you can't move. However, you have to do some awkward mods to the water rail and the injectors are inaccessible. If you look carefully at the photos in the link below, they appear to have used this arrangement.

https://www.jaguarhunter.org.au/Tech...es/MK2_EFI.htm

My own plan is to use the series 3 manifold, but chop the runners a few inches from the injector bosses and fabricate the rest of the system: U-bends to extend the runners and come back up to a plenum about level with the water rail. The objective is a system that works well, but is reasonably inexpensive and easy to make. However, I've a huge amount of bodywork to repair and replace before I get to do much on it.

 

That is the route I'm going to take as a next winter project. I currently have adapters that put an injector on top of the SU's and I'm having trouble with even fuel distribution. I think fuel puddles behind the bridge at low speed and then gets sucked in when I open the throttle. I am having trouble getting repeatable results, which makes it impossible to tune.

I made a manifold out of some stainless tubing with a 90 and a 45° bend and had plates laser cut to fit to the existing manifold carb mounting points and a flat plate to bolt the TBI unit to. The TBI is a General Motors unit, used on the 1988-95 trucks and Suburbans. They are very durable and seem to last forever. I've driven some high mileage GM trucks and the TBI units give no trouble. The injectors for the 5.7L match the flow rate of the ones I have now, so tuning will be minimal. I like these TBI units as they are self contained. The idle speed control and throttle position sensor are all there, as well a vacuum ports for the brake booster and ECU. I'll have to connect the wiring and figure out a throttle cable, but that shouldn't be too difficult.

The head and manifold are off a parts car, I'm using it for mock up purposes.

 

Jagboi, That's nice work. I can't wait to get to that stage. What did you do for the trigger wheel as space is tight at the front of the engine?

 

I obtained a 36-1 wheel from a Ford Escort 1.9, and then I machined a shoulder in the pulley of the 3.8. I made it a slight interference fit, and then I heat shrunk the trigger wheel onto the pulley at the correct orientation. I am using the Ford EDIS ignition system, and then made a bracket to hold the pickup sensor. The sensor came from a Crown Victoria.

Many Fords used a 36-1 wheel, so it was a matter of looking at cars in the junkyard until I found one that was the right size to use with the Jaguar pulley. Some Fords have grooves machined into the front pulley, the one I used was a discrete piece that was pressed onto the crankshaft damper.

In the last photo the sensor is unplugged, as I had the front suspension removed. The machine shop didn't give enough skirt clearance when the engine was machined, and the first time I drove it hard up a hill the engine seized. I dropped the pan and pulled out the two pistons that had seized and cleaned up the internals and then reassembled with two new pistons. Running fine so far!

 

Thank you! The idea was that if I ever wanted to return to the original carbs, I could; so I'm trying to make the modifications as bolt in as possible and reversible. The original Jaguar manifold is far from ideal from a flow point of view, but the choices are limited for what fits a B type head.

My "Plan B" if this doesn't work well, is I have a manifold from the J60 military engine and I'll put the TBI on top of that. The military engine had a big Solex downdraft carb, so replacing the carb with the TBI would be simple. The downside is that it is designed for a straight port head, so I'd need to change the head. I do have a head from a low miles XJ6 in my stash of spare parts, but that's a lot more work than bolting on my manifold in place of carbs.

It's interesting that the J60 manifold is clearly based on the 4.2 E type manifold, but converted to downdraft, rather than side draft. Jaguar was clearly making as few new patterns for casting as they could get away with. I'm not sure how ideal the flow path is either!