Patent ID: 8726878

Claim:
An internal combustion engine comprising: a cylinder head having a cylinder head base, a cylinder wall, and a piston movable along a cylinder axis and having a piston crown, a main combustion chamber being formed between said cylinder head base, said cylinder wall, and said piston crown, said cylinder head base having recesses for allowing valve connecting crosspieces to be set back with respect to said cylinder head base; a pre-chamber fitted into a bore in said cylinder head and fixed relative to said bore in a peripheral direction of said bore, a longitudinal axis of said bore being substantially parallel to said cylinder axis, a pre-chamber combustion chamber being formed in said pre-chamber; and a ring of transfer openings connecting said pre-chamber combustion chamber to said main combustion chamber, each of said transfer openings forming an angle with respect to said cylinder axis, said angle of each of said transfer openings located at a respective one of said recesses being greater than said angle of each of said transfer openings located distant from said recesses.