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.