What am I?

This class has sub classes within it:

Class 2 is for 2 Wheel Drive Rally Cars from 1451cc up to 1650cc normally aspirated.

Class 2A is for Cars from 1451cc up to 1650cc with only 2 valves per cylinder.

Class 2B is for Cars from 1451cc up to 1650cc with more than 2 valves per cylinder.