3.4 S type engine into xk 140

The '56 140 I purchased came without engine/trans/drive train. Also engine mounts were removed from the frame. Previous owner had inserted a chevy engine. I am attempting to return it to an XK engine installation. My dilemma is I have a rebuilt engine from a 65 3.4 S type and I am trying to determine what modifications I will need to do to make that work. I realize the bell housings between a 140 and an S type are different, mechanical clutch vs hydraulic. Does anyone know if the BH for a 140 will fit on the S type engine?
If not I may need to go to a hydraulic throw out bearing with the S type BH.

I have a 140 transmission, does anyone know if it will mate up properly with the S type BH?

There are other possible issues such as the wider oil sump on the S type engine, which may interfere with the exhaust pipes, but one problem at a time.
Thanks for your consideration.

Trans on engine is from S-type

Why don’t you fit the whole engine and transmission from the Stype to the XK. I appreciate the gear lever will require a remote linkage to bring the lever further back, but you would gain syncro on all 4 gears plus overdrive.
You need to use the flywheel, bell and starter motor together, as mixing and matching creates starter motor problems. You would be best converting to hydraulic clutch.
I have a MK9 in bits at the moment and might be able to answer some of your questions.

PS. The 140 bell housing will fit the engine but not the Stype gearbox, as the later gearbox front bearing and oil seal are retained by a machined recess in the bell housing rear face, whereas the old gearbox has its own bolted on cap.

I’d love to use the entire unit from the S-type, but like you say, the shifter would need to be brought back at least 10". Wouldn’t know where to begin with that.

A switch to an XJ top cover will get you the first couple of inches and a cranked-back lever will get you another couple, easily. If the knob is still a few inches forward of stock do you really have such short arms or worry about non-originality in a non-original car? Measure everything very carefully and I bet the difference is easily driveable. I would swap your cover for cost of postage

I’m just thinking ahead where I would rather not need to modify the trans tunnel or the carpet set if I don’t have to. What year XJ? And the XJ cover will not interfere with the OD?

I looked into fitting the full syncro box to my Mk9 and encountered the same gearbox top problems, although I was looking for another 10 inches. I’d almost worked out a provisional solution and it wasn’t that difficult.
Regarding the sump. Several sumps were fitted since xk120 days and with better oils being produced the capacity reduced each time. The sump fitted after the Stype one on the later XJ6 had the ‘ears’ cut off, so that might be an option if you can’t find an old straight tin sump. You would need to check what type of oil seal you have fitted. The asbestos rope might have been replaced by a modern conversion, and some early tin sumps just had a scroll with no oil seal.
I still would go for fitting the 4 syncro box as it transforms the car, overdrive is an extra bonus as well.

The covers are the same or OD/no OD. The knuckle is slightly different, so has to go with its cover, and of course the XJ version used a switch in the gearknob but a normal stick fits. Complete cover and forks/rods etc. are an easy swap.

Ok, thanks guys. I’m going to look at what I have at the shop today and do some more research.

As you have the all syncro S box go with it. The rear engine mounts can be fabricated,
as I have done on my 120. If you can locate a XJ top coxer it`s possible to extend as
photo, I have used this method on MK7 /SS100 and XK…
Peter B

BTW do you have the S type flywheel, which is the same as MK2 / 1.
Are the gearbox and engine from the Stype?

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Yes, the engine and gear box are from the s type. I guess I will go down that path. Thanks mike.

The gearbox mounting didn’t take much weight, the pair of rear engine mounts took virtually all of it.
What tachometer arrangements had you in mind as I think the 140 had a mechanical take off from the back of the exhaust camshaft whereas the Stype had a generator on the back of the inlet camshaft.?

I salvaged the engine and trans from the ’65 S type. I also salvaged the dash board and instruments. I intend to use the tach from the S type so I can use the generator on the inlet cam.

That’s quite a fancy extension you have their Peter. Would that be 1/4” aluminum plate welded up?
I take it the rods have extensions welded onto them as well?


Hey Peter,
I am open for swapping covers. See attached images. Is this what you are looking for?

I’m not ‘looking for’ anything. I was just offering to give you a longer XJ cover to help get your stick further back.

I don’t want payment for the cover but I don’t want to be left with half a gearbox or lose money for offering either. So if you send me that item I’ll switch covers and you can pay postage for me to send my long one back. You must replace the selector quadrant (thing the stick fits to) and special bolt and fibre washers & spring because the long top one is different and they need to stay with each top.

PM me your phone number if interested and we’ll sort the details.


Yes Mike welded, but only this rod to extend.
Peter B.

Hi Peter,
Sent you a PM.


Hi Peter,
I have received the XJ trans cover from Peter Crespin and I am taking it in to be extended. Because of the distortion of the aluminum due to the welding did you have to re-bush the center rod bushings? I need to add 4 inches to mine and there is a concern that the center piece being welded in will distort and the holes may no align.


It would take some work, but if you construct a simple jig, based on a piece of bar in the shift rod holes, would give you a better chance to maintain alignment.