The current 4 cyl. Alfa engines are basically identical. The 1,4 (now discontinued), 1,6 and 1,8 shares the same 82 mm bore, only the stoke differs. The 2,0 have 83 mm bore and due to the long stoke (91 mm) it’s fitted with two counter rotating balancing shafts. When the 147 was lanced the 105 hp 1,6 replaced the 1,4 but doesn’t have the inlet cam variator – as Numan says. The engine block is identical to the ones used in various Fiat and Lancia models – it’s named the Modulo engine family – in 4 and 5 cyl. form, the 5s having balancing shafts like the Alfa 2.0 (4 cyl.).