Benz BZ-4 Note: This item is currently in storage. The Benz BZ-4 is a six-cylinder, liquid-cooled, in-line engine of 200 hp. The German A.G.O. C II, Albatross, D.F.W. CV, Halberstadt C III and Halberstadt CV reconnaissance aircraft were among those using this engine. Click here to return to the Featured Accessions index.