Found this while cleaning up a 26 block. Crack from exhaust valve to number 3 cylinder. I searched the forum and found mostly answers from around 2009. So what is the current thinking on how to handle this?
Pin it and sleave cylinder,and put new insert in valve.
It needs drilled and pinned to stop propagation then the cylinder bored and sleeved and a new exhaust seat installed. Not something many can do in a home shop.
Jack must have posted just as I started typing but what he says. I have one just like it. Probably a common feature on an overheated engine.
Very common on the cheap 26-27 blocks.
"cheap 26-27 blocks. "What do you mean by that ?
Very common to find a crack at cylinder number 3 or 4 on the exhaust valve seat on 26/27's. Ken and Jack gave the right way to fix it. I see this on some early single cover engines but to date haven't found one that had two covers for the valve push rods. just saying.
Lorenzo,the newer they are,the cheaper made they were.
Made cheaper as in thickness or alloy or both or .....
Here is the rest of it....
Cylinder re-sleeve, valve seat and crack repair, or, find another block!
Depends on your budget and time frame. It was working when you tore it down. If cash and time are tight you can just reface the seat and valve and lap it in. This obviously is not the perfect answer but it will work.
What does it mean to drill it and pin it?