Crack or casting marks?

[Kootenay Pete]

Just curious if anyone has any idea if this is a well repaired crack on my 120hp GM 181 or if it is casting marks? The line goes the entire length and also follows the curve of the spark plug hole but doesn't appear to go around the sides.

 

[achris]

Casting mark...

And the 120 was a 153cu in. 181cu in is 3 litre (the old '140')

 

[Kootenay Pete]

Right on thank you. I was hoping it was casting, looked too consistent. And yes I meant 140, it's the one on my garage floor right now. I have the 120 in the boat right now with a cracked exhaust manifold. Didn't feel like swapping if it was just patched up. Thanks again.

 

[gr8shot]

Definitely just a casting mark. No water leaking, no problems!

 

[harringtondav]

Yes, casting mark. ...called a parting line where the upper (cope) and lower (drag) halves of the foundry mold meet.

 

[Kootenay Pete]

What a relief. That was the only concern with the 140. Thanks everyone.