Cracks behind sleeves IH350 block

[Mtjohnso]

Pulled the sleeves on the IH350 C175 engine. Was cleaning the surface of the engine block wall in preparation for installation of new sleeves. Then I felt an uneven spot. Upon close inspection I found cracks in 3 of the 4 holes. Some horizontal, some vertical.
These are dry sleeves.
There was no water in the oil so the old sleeves sealed off the path for any water leaks from these cracks. There were no deformities in the sleeves. There do not appear to be any other cracks in the block.
My plan is to seal these cracks, hone them and install new sleeves. I do not think there is a structural issues.
Thoughts on how to seal or resolve this issue?

 

[Janicholson]

My opinion is that there are risks in doing that. (not danger)Honing the native bore will make it a tad looser. Conducting heat is critical. If you put the thin sleeves in it the shape could be distorted by vertical cracks. I would first scout for a good used block, then as a last resort, I would put them in wet with sealant after cleaning the native bores to metal. Jim

 

[used red MN]

My plan is to seal these cracks,

How will you seal them? Sealing the sleeves at the top and bottom of their outside diameter to the block would probably be your best plan. Although this is probably a sketchy and possibly problematic repair.

 

[Fritz Maurer]

It only costs 150/hole for a bore and repair sleeve. I say 'only ' not because it's not my money but figure the cost of replacement block, must be hot-tanked before checking for cracks , your time spent driving/ hauling/shipping....and then finding out the replacement block is cracked too..... the price might be comparable to fixing your own block.

HOWEVER...... since the block is cracked and NOT the sleeves you removed, means someone else has already installed new sleeves over the cracks and run it.

I don't think I would hone them though.... you might mess up the sealing ability that apparently already exists in this situation.

 

[rrlund]

I knocked a hole in the block on Dad's Ford 8N trying to get the sleeves out. A good sized hole at that. I smeared some Permatex around it and put the new sleeve in. That was 30 years ago or more. It's still going.