A compression-ignition “split-cycle” engine (100) comprises: a
cylinder block (200) with an expansion cylinder (6) having an expansion
piston (7) that is adapted to move alternatively between a
top dead center (ETDC) and a bottom dead center (EBDC) by a
crankshaft mechanism (20) that causes a predetermined position of the expansion
piston (7) to correspond to a predetermined
crankshaft angle; a compression cylinder (2) having a compression
piston (1) that is adapted to move alternatively between a CTDC and a CBDC according to a predetermined angular phase shift in
delay to the expansion piston (7); a
cylinder head (30) that closes the cylinders and comprises a
crossover passageway (5) with an opening (5a) in constant communication towards compression cylinder (2) and an opening (5b) having a transfer valve (4) towards expansion cylinder (6), an intake valve (3) and a
exhaust valve (9); a means for opening / closing the transfer valve (4); a means for opening / closing
exhaust valve (9) at predetermined moments of the alternative cycle of the pistons, and a fuel
injector (8) in the
crossover passageway (5). The opening movement of the transfer valve (4) is carried out in advance 20° or more of
crankshaft angle with respect to the crankshaft angle of the ETDC, such that from the opening instant up to reaching the ETDC there is a substantial
equalization of pressure between the cylinders, such that between the ETDC and the CTDC a transfer occurs of the comburent fluid between the two cylinders, and such that
injector (8) injects the fuel (8a) starting from the achievement of the ETDC.