His work resulted in a six-cylinder water-cooled engine with increased bore which was capable of delivering 185 hp (138 kW) at 1400 rpm.

After a successful type test in February 1916 the engine was assigned the designation C.III (C for Conrad) by the German military.

[1] Due to insufficient production capacity at the Deutsche Motorenbau-Gesellschaft, the engine was produced by the Nationale Automobil-Gesellschaft (NAG).

[1] After NAG subsequently adapted the engine, it was uprated to 210 hp (157 kW) and successfully type tested in November 1916.

The Conrad C.III (Nag) engine was primarily allocated for training machines because it was found to be too heavy for use in fighter aircraft.