Has this 3.4 block been lined?

Hi all,
About 6 months ago I purchased a basket case XK150. the car had been gutted, and the roof cut off with an angle grinder. The original engine was gone, but another 3.4 from an XK150 was part of the package.
The seller at the time muttered something about having spend a lot of money on the engine, but the appearance made this claim dubious; The generator was gone, and an alternator bolted in place with a piece of angle iron and a coach bolt. The spark plug connectors were made from plastic coated bullet connectors, and the carbies were missing pieces.

Last week I finally got around to stripping down the engine as I didnt trust to simply install and try and fire it up.
The sump was held on with 1/2 a kilo of silicone, but once I got into the heart of the engine, things looked better.

(Engine as found)

Engine with your silicone sir?

New bearings and rings, but the pistons were domed. A search of the part number showed them to be 9.1 compression for a 3.8 litre.


A search of this forum says that having a 3.4 block bored to 3.8 is a bad thing, due to the thin walls. The 3.8 has dry liners pressed in.

Ok, my question to the forum is this… I THINK the PO had liners installed into the 3.4 block. I think I can see a line between the block and the liner, but I am not sure if this is just caused by machining… If anyone can confirm if this block is lined I would appreciate it…


Cheers, Jon (Melbourne Australia)

Its been a long time since I looked inside the XK engine but that step at the base of the bore looks like it is a sleeve. Quite a thin one but as I say, been a long time.

Thanks Robin,

That was my uneducated opinion as well. I can feel the ridge with my fingernail, and the ‘ring’ of the block material that you can see above the machined area is still rough. I cant see how an unmachined area could be lower than the machined area, unless it is a sleeve that has been inserted and then machined down.

Cheers, Jon.

I have bored many engines on a Rottler boring machine. This looks sleeved to me. But I always left the sleeve a few thou proud of the surface and then cut it down to flush. All the XK blocks I bored were 3.4, either C4820 or C8610 (from memory).

Thanks Art, It is a C8610 block.
The deck is flat and flush; the ‘ring’ I referred to is at the bottom of the bore. i.e. crankshaft end
So far this is sounding promising to use the block… It’s almost a 3.8 disguised as a 3.4 The massive amounts of additional horsepower this ‘sleeper’ will have will surprise everyone at the lights when I go Fast n Furious on their arses! :wink:
Cheers, Jon.

I have bored two of these blocks to 3.8 myself. The improvement is in
torque, maybe HP. I used std size E pistons. (so did you by the letter
grade I see on the top) When Jaguar bored these to 3.8 for experimental
reasons they had more failures than they could afford for a production
item. Maybe because they were put under heavy load like racing, maybe
not. I had several Mk7 blocks on hand and some free time at work. The
people who say this can’t be done are just librarians, not machinists.
They have paper cuts when some of us have skinned knuckles. I expect
your engine to run but no guarantees how long if pushed hard.

Art