V12 Rear Main Seal

I am replacing the rope seal in my Series 2 XJ12 (carbie engine).
Is there a more modern or neoprene seal available that does not leak?

There’s a better seal: The rope seal for a Ford 460 engine. It’s for a slightly
larger diameter, so the pieces of rope are a bit longer. They’re also graphite
impregnated. Other than that, same-o, same-o.

The rope seal generally doesn’t leak, and is generally more reliable than the
later lip seal – which won’t fit your engine anyway, at least not without
extensive modification. If you have leaks back there, you need to look at the
PCV system. You also need to confirm where the leak is actually coming
from, as the banjo bolt up top and the plug at the rear of the filter block are
both common leaks that get blamed on the rear main seal.

Remember to apply a thin bead of Loctite 518 from the rope seal groove to
the hockey stick groove on top of the main bearing cap before reinstallation.

– Kirbert

You also do not need the setting tool: it can be done using the crankshaft.

Or a strategically hit ball pein hammer will do! Just make sure the rope is very slightly proud of the block face and main bearing cap face before assembly. Not a lot! If either end of either half are too low you will build in a leak!