The main changes were to the valve timing, to give earlier opening of the inlet valves compared with the earlier 2 litre engine, though design changes to the cylinder head allowed for increased inlet valve diameters and better porting.
The main changes were to the valve timing, to give earlier opening and later closing of the inlet valves compared with the earlier 2 litre engine. Design changes to the cylinder head allowed for increased inlet valve diameters and better porting.