Hirth HM 508 (original) (raw)

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1930s German 8-cylinder inverted-V aircraft engine

HM 508
Type	Inline inverted 'V' piston engine
Manufacturer	Hirth
Major applications	Messerschmitt Bf 108

The Hirth HM 508 was an air-cooled, eight-cylinder, 60° cylinder bank angle inverted-V aircraft engine built in Germany in the 1930s.[1] It had a bore and stroke of 105 mm × 115 mm (4.1 in × 4.5 in) and developed 210 kW (280 hp) at 3,000 rpm.

HM 8U

HM 508A

HM 508B

HM 508C

270 PS (266 hp; 199 kW)[2]

HM 508D

280 PS (276 hp; 206 kW) at 3000 rpm[3]

HM 508E

150 kW (200 hp)

HM 508F

HM 508G

HM 508H

180 kW (240 hp), low fuel consumption variant, with centrifugal supercharger geared at 3.86:1 crankshaft speed for long-range record breaking aircraft.

• Ambrosini S.7
• Gotha Go 146
• Gotha Go 149
• Heinkel He 116
• IMAM Ro.63
• Messerschmitt Bf 108
• Siebel Fh 104
• Weserflug We 271 Experimental aircraft

Specifications (HM 508D)

[edit]

Data from Flugzeug-Typenbuch. Handbuch der deutschen Luftfahrt- und Zubehör-Industrie 1944,[4] Jane's fighting aircraft of World War II,[3] Jane's all the World's Aircraft 1938[5]

General characteristics

• Type: 60° V-8, inverted air-cooled piston engine
• Bore: 105 mm (4.13 in)
• Stroke: 115 mm (4.53 in)
• Displacement: 7.96 L (486 cu in)
• Length: 1,292 mm (50.87 in)
• Width: 683 mm (26.89 in)
• Height: 815 mm (32.09 in)
• Dry weight: 222 kg (489 lb) dry, unequipped

241 kg (531 lb) wet, equipped

Components

• Valvetrain: 1 inlet and 1 exhaust under-valve per cylinder driven by pushrods and rockers
• Supercharger: Centrifugal supercharger geared at 4.47:1 crankshaft speed
• Fuel system: 2x Pallas-Zenith 65 VAH2 carbutettors
• Fuel type: 87 Octane gasoline
• Oil system: Pressure system for crankshaft, pistons and reduction gear at 1.5–2.5 atm (22.04–36.74 psi; 1.52–2.53 bar): splash lubrication for camshaft and supercharger
• Cooling system: Air-cooled
• 1x Double Bosch magneto

Performance

• Power output:

• 280 PS (276 hp; 206 kW) at 3,000 rpm (5 minutes) at sea level

• 258 PS (254 hp; 190 kW) at 2,920 rpm (30 minutes) at sea level

• 225 PS (222 hp; 165 kW) at 2,790 rpm (max. continuous) at sea level

• Compression ratio: 6.2:1

• Specific fuel consumption: 0.220 kg/PSh (0.492 lb/(hp⋅h); 0.299 kg/kWh) at max continuous

• Oil consumption: 0.005 kg/PSh (0.011 lb/(hp⋅h); 0.007 kg/kWh) at max continuous

• Power-to-weight ratio: 1.266 PS/kg (0.566 hp/lb; 0.931 kW/kg)

• B.M.E.P.: 10.2 atm (10.3 bar; 150 psi)

• Reduction gear: Stoekicht sun and planet gears 0.666:1

Comparable engines

• Argus As 10

Related lists

• List of aircraft engines

1. ^ Gunston, Bill (1989). World encyclopaedia of aero engines (Fully rev. 2nd ed.). London: P. Stephens. p. 77. ISBN 1-85260-163-9.
2. ^ 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. pp. 398–399. ISBN 381120484X.
3. ^ a b Bridgman, Leonard, ed. (1989). Jane's fighting aircraft of World War II (1995 ed.). New York: Military Press. p. 294. ISBN 0517679647.
4. ^ 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. pp. 400–401. ISBN 381120484X.
5. ^ Grey, C.G.; Bridgman, Leonard, eds. (1938). Jane's all the World's Aircraft 1938. London: Sampson Low, Marston & company, ltd. pp. 60d – 61d.