Abnormal Iron in 273 Cylinder Bore

[Torqueflite]

I broke down a 1965 273 and found an odd-looking/feeling area of bore in one cylinder. The block is standard with .004" taper. This area appears and feels rougher than the surrounding wall, almost like the iron frothed up during casting. At first, I thought it was rust pitting, but it doesn't look like any pitting I've come across, and there is no sign of standing water in any cylinder. My concern is how deep it goes and if boring will open up more of it. Looking at the outside of the cylinder through the water jacket, I see no abnormality in this area.

The machinist will have the last word on whether the cylinder will clean up at .030, .040 or require a sleeve, but I'm curious if anyone else has come across a similar type of oddity in the cylinder wall.

 

[Moparpuller]

I broke down a 1965 273 and found an odd-looking/feeling area of bore in one cylinder. The block is standard with .004" taper. This area appears and feels rougher than the surrounding wall, almost like the iron frothed up during casting. At first, I thought it was rust pitting, but it doesn't look like any pitting I've come across, and there is no sign of standing water in any cylinder. My concern is how deep it goes and if boring will open up more of it. Looking at the outside of the cylinder through the water jacket, I see no abnormality in this area.

The machinist will have the last word on whether the cylinder will clean up at .030, .040 or require a sleeve, but I'm curious if anyone else has come across a similar type of oddity in the cylinder wall.View attachment 1715897551

Looks like it had water in it at one point Possible head gasket seeping

 

[Inertia]

Is that a front cyl , mark toward front ?

Perhaps too long of a water pump bolt ?

 

[Bewy]

Sleeved in a prior life?

 

[RustyRatRod]

Bore it and rock on.

 

[gzig5]

Looks like carbon build up to me, but I haven't slept at a Holiday Inn lately. Maybe see if that scribe will flake some of it off? That is too thin and uniform to be some sort of inclusion the casting IMO.

 

[toolmanmike]

Only your machinist will know for sure.

 

[Torqueflite]

Looks like carbon build up to me, but I haven't slept at a Holiday Inn lately. Maybe see if that scribe will flake some of it off? That is too thin and uniform to be some sort of inclusion the casting IMO.

Nothing flakes off. The rough area seems as hard as the rest of the bore.

 

[Torqueflite]

Only your machinist will know for sure.

Definitely. I've not come across something looking like this, so I was curious if others have. It'll either get cleaned up or sleeved.

 

[pishta]

that thing would have smoked.....Got a ball hone? It looks like a .020 would clean that right up.

 

[cudamark]

Melted piston? Whatever it is, you want to remove it. If it won't clean up with a rebore, either sleeve it or get another block. Mag it first to make sure it's not a seeping crack.