Benz BZ 4S In-line Engine


Display Status:

This object is on display in the Boeing Aviation Hangar at the Steven F. Udvar-Hazy Center in Chantilly, VA.

Benz BZ 4S In-line Engine

Collection Item Summary:

Benz & Cie of Mannheim, Germany, manufactured nearly 6,500 Benz BZ 4S engines between 1914 and 1918. The engine followed the usual German practice of having a separate water-cooled cylinder bolted to the crank case by long studs. The studs passed through the crank chamber top half and secured the crank shaft bearings between the top and bottom halves of the crank case.

The BZ 4S powered various German reconnaissance, bomber, and infantry patrol aircraft, including the Ago C.II, C.IV, and C.VII; A.E.G. J.I and J.II; Albatros J.I and C.VII; D.F.W. C.V; Halberstadt C.V; and Junkers J.I.

Collection Item Long Description:



Inventory Number


Physical Description

  • Type: Reciprocating, In-line, 6 cylinders, liquid cooled
  • Power rating: 205 kW (275 hp) at 1,500 rpm
  • Displacement: 18.8 L (1,149 cu in.)
  • Bore and Stroke: 145 mm (5.71 in.) x 190 mm (7.48 in.)
  • Weight: 385 kg (848 lb)

Credit Line

Found in collection


Country of Origin



Length 149.9 cm (59.0 in.), Width 53.1 cm (20.9 in.), Height 131.3 cm (51.7 in.)

Data Source

National Air and Space Museum

Restrictions & Rights

Do not reproduce without permission from the Smithsonian Institution, National Air and Space Museum


PROPULSION-Reciprocating & Rotary