Zündapp 9-092

9-092
	Rear view of the 9-092 engine on display at the Technikmuseum Dessau (note:displayed upside-down)
Type	Air-cooled inverted inline-four engine
Manufacturer	Zündapp
First run	1938
Major applications	Gotha Go 150, Siebel Si 202B
Number built	c.200
Developed from	Zündapp Z 9-090

The Zündapp 9–092 or Z 92 was a German four-cylinder, air-cooled, inline aero engine made by Zündapp and used in light aircraft of the late-1930s.^[1]

Design and development

The engine was developed from the smaller Zündapp 9-090. This inverted engine featured dual gear-driven camshafts with the valve rocker cover acting as the oil tank. It featured a single Bosch magneto ignition system. A total of approximately 200 engines were produced.

Applications

Engines on display

Preserved examples of the 9-092 engine are on public display at the Deutsches Museum, Munich and Technikmuseum Dessau.

Specifications

Data from Flugzeug-Typenbuch. Handbuch der deutschen Luftfahrt- und Zubehör-Industrie 1944^[2]

General characteristics

Type: Four-cylinder air-cooled inverted inline piston aircraft engine
Bore: 85 mm (3.35 in)
Stroke: 88 mm (3.46 in)
Displacement: 2 L (122.05 cu in)
Length: 800 mm (31.5 in)
Width: 350 mm (13.8 in)
Height: 560 mm (22.0 in)
Dry weight: 60 kg (132 lb) dry, unequipped

65 kg (143 lb) wet, equipped

Components

Valvetrain: 1 inlet and 1 exhaust under-head valve per cylinder driven by pushrods and rockers
Fuel system: Downdraught carburettor
Fuel type: 78 Octane gasoline
Oil system: pressure feed at 0.2–0.35 atm (2.9–5.1 psi; 0.20–0.35 bar)
Cooling system: Air-cooled

Performance

Power output:

50 PS (49 hp; 37 kW) at 2,300 rpm (30 minutes) at sea level
45 PS (44 hp; 33 kW) at 2,225 rpm (max. continuous) at sea level
40 PS (39 hp; 29 kW) at 2,150 rpm (cruise) at sea level

Specific power: 25 PS/L (0.40 hp/cu in; 18.39 kW/L)
Compression ratio: 6.2:1
Specific fuel consumption: 0.220 kg/PSh (0.492 lb/(hp⋅h); 0.299 kg/kWh) at max continuous
Power-to-weight ratio: 0.833 PS/kg (0.373 hp/lb; 0.613 kW/kg)
B.M.E.P.: 9.8 atm (9.9 bar; 144 psi)

References

^ Flight - 'The Belgrade Show' - 9 June 1938, p. 561. Retrieved: 18 December 2012
^ Schneider, Helmut (Dipl.Ing.) (1944). Flugzeug-Typenbuch. Handbuch der deutschen Luftfahrt- und Zubehör-Industrie 1944 (in German) (Facsimile reprint 1986 ed.). Leipzig: Herm. Beyer Verlag. p. 419. ISBN 381120484X.