Cracked cylinder block

How can I easily tell if my cylinder block is cracked? I have a couple of spare XJ engines that I picked up years ago and I was told one of the blocks had a crack in the cylinder wall. I can't see anything obvious.

I would rather not put it into operation to find out!

 

Usually a Cracked Block is rather obvious. It's a Cracked Head that can be almost invisible.

The "Old School Method" is:

Tie it up an suspend it from something overhead.
Use a screwdriver handle or a hammer handle and "Ring" it.

If it has a flat, dull ring to it ... it's suspect!
If it "Rings True" then it might be OK.

The right way is to have it checked-out by a Machine Shop.
They'll either X-Ray it or Magna-Flux it to inspect for a crack; someplace.

 

If it's off the engine, machine shops will Magna-flux it free !
just bring it in clean. That's for the iron liner only. Aluminum cracks take a process of spreading on a dye, then a "developer" that shows cracks.
That one might cost a little.

 

Alrighty then. I'll try the old school method first of beating it with a hammer to see if it screams in tune.