Engine numbers on flywheel, crankshaft

Does anyone have (or can take) pics of the engine number on the flywheel of an XK engine?
Also on the crankshaft?
All help appreciated!

I can take one of the engine number on an E-type flywheel, does that help? Not saying there isn’t one, but I can’t recall seeing an engine number on a XK120 flywheel or crankshaft.

Confirmed. The only places I found the number on my XK120 engine were on the head and the usual place over the oil filter. Different story on my E-type engine.

First photo, E-type. Second photo, lightweight XK120 flywheel. Only number on it is the N 35 X near the B balance mark.

While we are talking about engine stampings, does anyone know the significance of the letters VYO stamped on the timing chain cover and the block next to it on the left side of my motor? I never noticed them until recently.

The timing cover and block are a matched set, were put together before the top and bottom decks were machined together, then stamped with identifiers before they were separated for assembly work, so they could be reunited later.

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Yes. The timing cover, block and main caps are all stamped with a three letter code that identifies them as a machined set. You can see the letters BSD stamped along the lower pan rail and the corresponding main cap stamping in the photo below.


Thanks. There is always something to learn.

My enquiry here started because an XK owner here reported to me the numbers and letters on his flywheel BV4373. I guessed that the V4373 was the engine number from which the flywheel had come (but this was not as obvious as you might think, as the original engine for this particular car was not V4373!). But what was the “B”? A clue from Terry McGrath led me to this - which was already in effect picked up by others on this list:
XK120 workshop manual: for refitting the flywheel: “Turn the engine until Nos. 1 and 6 pistons are on T.D.C. and fit the flywheel to the crankshaft flange so that the “B” stamped on the periphery of the flywheel is at approximately the B.D.C. position, when the dowel and bolt holes are in line. (This will ensure that the balance mark “B” on the flywheel is in line with the balance mark on the crankshaft, which is a group of letters stamped on the crank web just forward of the rear main journal.)”
Thanks for the pics of the timing case numbers too! Happy to see more of those.

SO: are we redefining “matching numbers” here?!! Show me your flywheel!!

Hi Mike, Great information, thanks! From what XK120 did that flywheel come? Do you know the story of the car?

Hi Bob, What car do you have? Reply privately if you prefer elmgreen at ihug dot com dot au.

Unfortunately, I can’t recall how I received it. I would have to check the parts book and service manual, but I believe that the car I own, 672027, early April, 1952, is too early to have come with it originally.

John, The chassis # is S 813007 DN. I am not too concerned about clones and I think there is some benefit to having the information out there. This forum shows time and again that people are interested in more issues than the factory tracks.

VS 1119

Date: Mon, 28 May 2001 From: “R,J,G&KReilly” Subject: [xk] Front Cover Matched to Block I noticed something interesting about our engines. The front timing cover is marked on the left side with the same two letters as the main bearing caps and the corresponding letters on the block. This means each front cover is matched to its specific block just like the main bearing caps are. The reason has to be that they were bolted together with the two alignment pins in place before the final machining of the top deck (head interface) and the bottom deck (oil pan interface) as well as the line boring of the main bearings. Then they were separated, and possibly some other machining operations may have been done before they were cleaned and reunited for the assembly work. Rob Reilly

Is there nothing new under the sun?!

Hi Bob, I agree with what I think you are thinking - i.e. that we are better off shining as much light as possible on what is original and correct for our cars, rather than hiding the information for fear that someone will make a “clone”. Of course, diligent a cloner could well undertake a detailed study of what we see on forums like this and make a very convincing clone, but the free availability of well-informed information is the best way to guard against clones being accepted as genuine. A prime example is a superb looking XK120 resto-mod offered for auction in recent years, claiming a correct XK120 chassis number, but which was withdrawn from the auction when the real car with that chassis number came up for sale a few weeks before the auction (a wreck in the USA). If the auction house had allowed the car to be offered without a chassis number, and if the seller of the real car in the USA had offered it online without a chassis number, the scam would never have been unearthed. All the big auction houses insist on chassis numbers etc these days - as does Bring A Trailer. They hate someone coming back after buying car at auction and claiming the car that was sold was not in fact, as claimed (say), “numbers matching”. So, let’s keep “shining the light”.

Hi Mike, The block with the BSD stampings, is that your 3.8 litre Mk IX block NC1265-8?

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Thanks, Morris! Love to know more about your car, too!

The numbers on my early 6-bolt crank. Don’t really know what they mean, but they’re nothing to do with the engine number, for sure!

Forgot to check the flywheel for numbers.

chris if these numbers are cast in they will be part of cranks forge numbes as an unmachined item.
Almost certainly somewhere on it should be some sort of number hand stamped with number stamps?