I'm trying to identify the cooling system drain plug on my a12. I see two likely bolts in the left side of the block adjacent to the centre welch plug.

One is directly below the welch plug protruding orthogonally from the block. The other is below and behind the welch plug and protruding at an angle.

Which one is it?

It is just below the center welch plug on the left (manifold side) of the engine block. This appears about halfway down the side of the block:




It is only halfway from the top because below that is the upper half of the crankcase. The water passages only go half-down the block.

That photo above is the late-style engine. So a 1974 A12 will have it there.

The early A12 engine (1970-1974) has it in roughly the same position, but exactly under the center welch plug.

Thanks DD. I have a late model a12 and it appears I have both bolts! One directly underneath and one behind.

Attach file:

---

  IMGP3105_s.jpg (54.86 KB)

Which block casting number is that?

H79 or H50 ???

Not sure where to check the casting number, but it says M22 where it says M72 in your picture of the late model engine.

Yes, that is the block casting number.

M22: A12 block casting from 1974-1978 B210

Quote:
Orthogonally? Well I live & learn. I had to look it up but that's another word that I can add to my vocabulary.

Link 1
Link 2
Link 3
Orthogonal entertainment

Oops, edited to correct blatant spelling error.

One looks to be protruding hexagonally, but the other looks to be protruding circularly. Could be just the photo?