MOTORENFABRIK HATZ in West Germany has been manufacturing air-cooled and water-cooled diesel engines for the last 78 years. Our single-cylinder, 70 Series, has met with worldwide success. Our new single-cylinder line. SUPRA, builds on that success and introduces several unique features including a new mass balancing system, both clockwise and counterclockwise rotation, and encapsulation for noise reduction. This paper describes the overall design features of the SUPRA including the unencapsulated as well as the encapsulated design.