Hi,
Sonic testing a block is a way of checking how thick the cylinder walls are. If they are too thin the block should not be used.
Magnafluxing is a dye they put on parts such as rods, heads,crank,etc to see if there are any tiny cracks in the metal.
Shot peening is used after the rods are magnafluxed and found to be good. Small round balls are shot at the metal part to pound the metal molecules , this makes the part alot stronger.
good Luck,
Perry.
