Was the Failure Catastrophic or Can I Drive My 1977 XJ12 Jaguar This Season? 

White (or creame, or whatever) is a beautiful colour. Chrome and white is sexy combi nation.

You lost me on this one - why did you not simply verify whether the roll pin on the distributor shaft has not sheared first? you mentioned this possibility during the intro so I was expecting this to be your first check? I'm sure you know what you are doing but I'm confused now - hopefully its going to be a simple fix

Love the v12 never had it happen to me but can see how that pin could wear or shear hopefully that's it best of 🤞

The jackshaft is a red herring I think. The position would be critical if it was a dog type drive, but as it is a geared drive, the jackshaft can be in any position provided that you locate the distributor correctly to align the rotor with the correct position for TDC, which you have now done. As the timing still doesnt seem quite right ( she is very lethargic on throttle response) I would begin to wonder whether the timing chain has slipped, and your cams are out . I dont believe that this is an interference engine, so serious damage unlikely to ensue, as the valves cant hit the pistons (but check to be sure!) . Your idea of removing a cam cover to check the cam timing is a good one, and should provide a definitive answer. On the XK engine, the cam sprockets are bolted on to the cam, and if those bolts came loose, the timing would slip. I'm not sure how the sprockets are attached on the V12, but that would be another obvious thing which could have hapenned. Finally, you are sure the distributor was securely located in the block?

The broken distributor pin was my first thought when you mentioned the bump followed by popping back through carb. Either that or the distributor was loose and had jumped a tooth on the worm gear. The pin would have been my first go to.

That was very interesting to see the internals like that, thank you for filming it 😊

I hope it will be up and running soon, it's the perfect car for a long trip.

That's a different view of the engine. Why would the distributor jump by the car hitting a bump? Surely that would mean something else is broken like the dizzy casing allowing the thing to move in the block.

Nice detective work. Fingers cross the dizzy swap will fix the issue. Those USB cameras come in very handy.

If the dizzy is freely spinning, I'm having a hard time wrapping my head around the roll pin shearing as a probable cause. Surely it would have to become seized to exert that much force on the pin. Why not stick the borescope into the timing chain tensioner access hole in the timing cover and see if the plastic tensioner is cracked? I know that rubber plug is a pain but it seems like it'd be worth the peace of mind. Good luck with it Adam!

Adam I hope that is the problem like you say a easy fix good look and I will be waiting to see the outcome best regards Andy Allen.

No jackshaft on the X305 6.0. Just an idler in its place. 😊

Stick a plug in number 1 on the other engine and you'll know if its on a compression stroke. :-)

Thumb up!

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