The Walter NZ 85 was a seven-cylinder, air-cooled, radial engine for aircraft use built in Czechoslovakia by Walter Aircraft Engines in the late-1920s.

Using common cylinders and parts from the earlier Walter NZ 60 (Novák-Zeithammer) engine the NZ 85 and the nine-cylinder NZ 120 were designed together.^[1] Lightened and tuned developments were known as the NZ 90 and NZ 95.

• Aero A.34
• Avia BH-20
• Avia BH-29
• Breda Ba.15
• Couzinet 30 (intended application)
• Gribovsky G-8
• Hopfner HS-8/29
• IMAM Ro.5
• Letov Š-118
• Orta-Saint Hubert G.1
• Savoia-Marchetti S.56
• Shavrov Sh-1

Data from Němeček.^[2]

• Type: Seven-cylinder radial piston engine
• Bore: 105 mm (4.13 in)
• Stroke: 120 mm (4.72 in)
• Displacement: 7.27 L (444 cu in)
• Length: 741 mm (29.2 in)
• Diameter: 990 mm (39.0 in)
• Dry weight: 125 kg (276 lb)

• Fuel system: Zenith carburettor
• Cooling system: Air-cooled

• Power output: 74 kW (99 hp)

Comparable engines

• Armstrong Siddeley Genet Major

Related lists

• List of aircraft engines

• Gunston, Bill. World Encyclopaedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9
• Němeček, Václav. Československá letadla I (1918-1945) (Czechoslovak Aircraft I (1918-1945)). Third edition, Naše vojsko, Prague. 1983.