Hirth HM 508

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.

Variants

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.

Applications

Specifications (HM 508D)

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

References

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

[Gunston-1] Gunston, Bill (1989). World encyclopaedia of aero engines (Fully rev. 2nd ed.). London: P. Stephens. p. 77. ISBN 1-85260-163-9.

[schneider508C-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.

[FAoWWII-3] Bridgman, Leonard, ed. (1989). Jane's fighting aircraft of World War II (1995 ed.). New York: Military Press. p. 294. ISBN 0517679647.

[schneider-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.

[JAWA1938-5] Grey, C.G.; Bridgman, Leonard, eds. (1938). Jane's all the World's Aircraft 1938. London: Sampson Low, Marston & company, ltd. pp. 60d–61d.

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