Cracks on C69A block
 

I picked up a C69A block and after cleaning noticed some ripple-like lines on one side. Magnafluxing does not show these to be cracks, so I'm wondering if these are just irregularities in the casting. The side of the other bank is smooth. There is a short crack near the water pump mounting, probably from freezing, and I think that will be repairable, but I'm concerned about these other lines.


My question is - are these marks typical of some castings? Perhaps the Canadian foundry had different quality control.

Re: Cracks on C69A block
 

Nothing to worry about.

Re: Cracks on C69A block
 

I have a similar "crack" on the side of my block - I cleaned it really well and decided it was a casting flaw and only cosmetic. I believe your's are the same. Especially if you have had them magnafluxed.

I think I posted a photo here.

Mart.

Edit: I did. Here's the thread.
https://www.fordbarn.com/forum/showthread.php?t=243362

Re: Cracks on C69A block
 

Looks common to me, seen the same thing on a lot of blocks.

Re: Cracks on C69A block
 

Yep same here. The C69A block out of Canada is a good one too. I think these have the later insert bearings a la 8BA.


GB

Re: Cracks on C69A block
 

I have a '39 Canadian Merc block. It has similar ripples. Normal, as far as I'm concerned.

Re: Cracks on C69A block
 

Casting sand shift in the mold before or during the pour?
The pour line was fed molds via a long vertical arms hanging from a overhead chain/conveyor. Ladle accidentally bumped the the mold while pouring?
Improper cast sand mix, mold not packed tight enough.
Could be many reasons for the cause.

Re: Cracks on C69A block
 

It could just be shrinkage but there are other possibilities. It's not uncommon to see ripples & blemishes on the outer surfaces or the castings. I understand how they made the cores but I'm not sure how they prepared the outer shell mold. The shell might get blemishes from the workers tying the cores inside it. There wasn't a lot of room in there while assembling the mold. The tie wire resembles baling wire and it had to be tied up in there.

Todd may have a good idea how that may have been done.