How many movies have M. S. Viswanathan and Y. G. Parthasarathy collaborated on?

They have worked on 4 movies together! Their first movie together was Sila Nerangalil Sila Manithargal (1975) and was their highest rated movie together. They have not worked together since Oru Nadigai Nadagam Parkiral (1978). They are most known for their drama films together.