High Quality Content by WIKIPEDIA articles! The all alloy Alfa Romeo Twin Cam engine series was an inline-4 cylinder engine produced by Alfa Romeo from 1954 to 1994. For earlier Alfa Romeo engines featuring twin camshafts, refer to the main Alfa Romeo page. For the later 8 or 16-valve Twin Spark engines which also feature twin camshafts, please refer to the Alfa Romeo Twin Spark engine page. The Alfa Romeo Twin Cam engine was introduced in the 1290 cc Giulietta of 1954. The features of the Giulietta engine included: Aluminium alloy engine block with cast-iron cylinder liners, Aluminium alloy cylinder head with hemispherical combustion chambers, Forged steel crankshaft running in five main bearings, Double overhead camshafts driven by a double row timing chain, Camshafts directly actuate valves via bucket tappets, Two inclined valves per cylinder with near central located spark plug, Inlet and exhaust valves separated by an angle of 80 degrees.