Is a 60 series Detroit diesel a 2 cycle or 4 cycle engine?

A DDC 60 Series is a 4 stroke cycle engine. The 2 strokers are: 51, 53, 71, 92, 110, & 149 series engines with the number of cylinders and configuration as a prefix.

Example: 6-71 is a 2 stroke with 6 cylinders of 71 cubic inch displacement per cylinder.

8v-92 is an 8 cylinder engine of 92 c.i. displacement per cylinder in a "V" configuration.