An engine block of an internal combustion engine is disclosed. The engine block may have a piston and at least one gas exchange valve. The piston may have a piston skirt having a first center axis. The piston may also have a piston head delimiting the piston skirt at the top with a diameter D. The piston head may have a piston head edge and a piston head recess with a piston recess wall having a height H. At least one valve pocket may be formed into the piston head edge. The at least one valve pocket may have a valve pocket depth T with respect to the piston head edge. The valve pocket depth T may fulfill the following condition with respect to the wall height H: 0.05 H