Benz Bz.IV

Bz.IV
A Benz Bz.IV at the National Air and Space Museum's Udvar-Hazy Center (2017)
Type	Inline piston engine
National origin	Germany
Manufacturer	Benz
First run	c. 1916
Number built	6,400
Developed from	Benz Bz.III

The Benz Bz.IV was a German six-cylinder, water-cooled, inline engine developed for aircraft use. Deliveries began in 1916, and some 6,400 were produced.

Design and development

The Bz.IV was a dual-camshaft design, with two intake and two exhaust valves per cylinder. The cylinders were cast iron surrounded by a sheet metal cooling jacket. The crankcase was aluminium and pistons were initially steel but later versions had aluminium pistons. A high compression version of the engine (Bz IVsü) was produced from 1917 onwards ^[1] . In February 1918, pistons from a Bz.IV were the first captured aluminium pistons to be examined by the British Ministry of Munitions. ^[2]

Variants

IV

(1916) Main production variant produced by Benz & Cie.

IVmarta

(1916) Licensed production of the Benz Bz.IV in Austria-Hungary by Magyar Automobil Részvény Társaság Arad (MARTA). The Marta produced version was heavier and had a lower compression ratio than the German original.

IVsü

(1917) Overcompressed version producing 205 kW (275 hp) at altitudes above 2,000 m (6,562 ft). Also known as the IVs, IVü or IVaü. The "ü" in the model description stands for überverdichtet (German: "overcompressed”) while the "s" denotes the use of steel cylinder liners. ^[1]

Applications

• AEG C.VI
• AEG J.I
• AGO C.IV
• Albatros C.VII
• Albatros C.XIV
• Albatros J.I
• Chitty 2 (racing car)
• DFW C.V
• Dobi-II
• Friedrichshafen FF.49
• Friedrichshafen G.II
• Halberstadt C.III
• Halberstadt C.V
• Junkers J.I
• LFG Roland C.III
• LVG C.VI
• NAVO RK-P4/220
• Pfalz D.XII
• Pfalz D.XIV
• Siemens-Schuckert R.III
• Siemens-Schuckert R.IV
• Siemens-Schuckert R.V
• Siemens-Schuckert R.VI
• Zeppelin-Staaken R.IV
• Zeppelin-Staaken R.XVI

Specifications

Data from ^[3]

General characteristics

• Type: 6-cylinder, water-cooled, inline aircraft piston engine
• Bore: 145 mm (5.7 in)
• Stroke: 190 mm (7.5 in)
• Displacement: 18.825 L (1,148.8 cu in)
• Length: 1,990 mm (78.3 in)
• Width: 530 mm (20.9 in)
• Height: 1,150 mm (45.3 in)
• Dry weight: 370 kg (815.7 lb)

Components

• Valvetrain: Twin inlet and exhaust valves operated by pushrod actuated double rockers
• Fuel system: Two Benz 2-jet carburettors feeding three cylinders each
• Fuel type: Gasoline specific gravity 0.72
• Oil system: Pressure feed at 0.2 MPa (28 psi): 50% Vacuum Heavy, 50% Sternol
• Cooling system: Water-cooled

Performance

• Power output: 170 kW (228.0 hp) at 1,400 rpm
• Specific power: 9.1 kW/L (0.2 hp/cu in)
• Compression ratio: 4.91:1
• Fuel consumption: 85.2 L (150 imp pt) / hour
• Specific fuel consumption: 0.495 L/kW/hr (0.65 pts/hp/hour)
• Oil consumption: 2.6 L (4.5 imp pt) / hour
• Power-to-weight ratio: 0.3796 kW/kg (0.231 hp/lb)

See also

Related lists

• List of aircraft engines

References

1. Düsing, Michael (2022). German & Austro-Hungarian Aero Engines of WW1. Vol. 1. Aeronaut Books. pp. 197–205. ISBN   9781953201515.
2. "Report on Aluminium Pistons from 230 HP Benz Engines". Flight . 4 July 1918.
3. Grey, C.G. (1969). Jane's All the World's Aircraft 1919 (Facsimile ed.). David & Charles (Publishing) Limited. pp. 1b to 145b. ISBN   978-0-7153-4647-1.

Bibliography

• Grey, C.G. (1969). Jane's All the World's Aircraft 1919 (Facsimile ed.). David & Charles (Publishing) Limited. pp. 1b to 145b. ISBN   978-0-7153-4647-1.
• Kroschel, Gunter and Helmust Stützer. (1977) Die deutschen Militarflugzeuge 1910-1918 Wilhelmshaven: Lohse-Eissing Mittler.