Hirth HM 504

HM 504
Hirth HM 504 installed in a Klemm Kl 35
Type	Inline piston engine
Manufacturer	Hirth
Major applications	Bücker Bü 131

The Hirth HM 504 is a four-cylinder air-cooled inverted inline engine. The 504 was a popular engine for light aircraft of the 1930-40s and it was used to power a number of Germany's trainer aircraft of WWII. The engine featured a cast magnesium alloy crankcase. The Hitachi Hatsukaze Model 11 was a Japanese licensed version.

Applications

• Bücker Bü 131
• Bücker Bü 181
• BŻ-1 GIL
• Klemm Kl 35
• Repulogpegyar Levente II
• BŻ-1 GIL (helicopter)

Specifications (HM 504)

General characteristics

• Type: 4-cylinder air-cooled inverted inline
• Bore: 105 mm (4.13 in)
• Stroke: 115 mm (4.53 in)
• Displacement: 3998 cm³ (244 cu in)
• Length: 957 mm (37.70 in)
• Width: 505 mm (19.90 in)
• Height: 726 mm (28.60 in)
• Dry weight: 104 kg (230 lbs)

Components

• Valvetrain: 1 inlet and 1 exhaust valve per cylinder
• Fuel type: 77 octane
• Cooling system: air

Performance

• Power output: 105 hp at 2500 RPM
• Compression ratio: 6.00:1
• Power-to-weight ratio: 2.87 lb/hp at cruise speed

See also

Related development

• Hitachi Hatsukaze
  

Comparable engines

• Alfa Romeo 110
• Blackburn Cirrus Minor
• de Havilland Gipsy Minor
• Elizalde Tigre IV
• Menasco C4 Pirate
  

Related lists

• List of aircraft engines
  

References

Bibliography

• Gunston, Bill. World Encyclopaedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9

External links

• Göbler-Hirthmotoren Company website