Hirth HM 512
{{Short description|1930s German aircraft engine}}
| {{Infobox Aircraft Begin
| name=HM 512 | image= | caption= }}{{Infobox Aircraft Engine |type=Air-cooled inverted V-12 piston engine |manufacturer=Hirth-Motoren G.m.b.H, Stuttgart |designer=Hellmuth Hirth |national origin=Germany |first run= |major applications= |produced= |number built=small numbers{{harvnb|Gunston|1989|pp=76–7}} |program cost= |unit cost= |developed from=Hirth HM 506 |variants with their own articles= }} |
The Hirth HM 512 was a 12-cylinder development of the earlier, 6-cylinder HM 506, produced in the late 1930s. Both were supercharged, inverted V, air-cooled engines.{{cite web|last1=Pearce|first1=William|title=FKFS Gruppen-Flugmotor A, C, and D|url=https://oldmachinepress.com/2016/03/24/fkfs-gruppen-flugmotor-a-c-and-d/|website=oldmachinepress.com|accessdate=8 May 2016}}
Design and development
The HM 512 shared the same bore and stroke (105 mm × 115 mm) and 6:1 compression ratio with the rest of the HM500 series air-cooled engines. Other shared features were Hirth's use of roller bearings in the crankshaft and at both ends of connecting rods. The crankshaft was of typical Hirth multipart design, the 12-cylinders requiring 7 roller bearings. Like the HM 508, the drive was geared down by 1:1.5.
Variants
Applications
Specifications (HM 512A)
{{pistonspecs
|
|ref=Flugzeug-Typenbuch. Handbuch der deutschen Luftfahrt- und Zubehör-Industrie 1944,{{cite book |last=Schneider |first=Helmut (Dipl.Ing.) |title=Flugzeug-Typenbuch. Handbuch der deutschen Luftfahrt- und Zubehör-Industrie 1944 |date=1944 |publisher=Herm. Beyer Verlag |location=Leipzig |isbn=381120484X |edition=Facsimile reprint 1986 |language=German |pages=402-403}} Jane's all the World's Aircraft 1938{{cite book |title=Jane's all the World's Aircraft 1938 |editor1-last=Grey |editor1-first=C.G. |year=1938 |publisher=Sampson Low, Marston & company, ltd |location=London |editor2-last=Bridgman|editor2-first=Leonard|page=61d}}
|type=Inverted 60° V-12-cylinder air-cooled piston
|bore={{cvt|105|mm|2}}
|stroke={{cvt|115|mm|2}}
|displacement={{cvt|11.94|L|cuin}}
|length={{cvt|1542|mm|2}}
|diameter=
|width={{cvt|665|mm|2}}
|height={{cvt|815|mm|2}}
|weight={{cvt|270|kg|0}} dry, unequipped
::::{{cvt|314|kg|0}} wet, equipped
|valvetrain=1 inlet and 1 exhaust under-valve per cylinder driven by pushrods and rockers
|supercharger=Light alloy centrifugal type, driven at 4.4 times crankshaft speed.
|turbocharger=
|fuelsystem=SUM 807 carburetor with automatic mixture control and equipped for inverted flight.
|fueltype=87 Octane gasoline
|oilsystem=Metered fresh oil to cylinder barrels and crankshaft bearings at {{cvt|3.5|-|4.5|atm|psi bar|2}}. Splash lubrication for supercharger and camshaft. Stökicht Sun and planet reduction gear lubricated by high pressure oil.
|coolingsystem=Air-cooled
|power=
:*{{cvt|400|PS|hp kW|0}} at 3,110 rpm (1 minute) at sea level
:*{{cvt|360|PS|hp kW|0}} at 3,000 rpm (5 minutes) at sea level
:*{{cvt|330|PS|hp kW|0}} at 2,910 rpm (30 minutes) at sea level
:*{{cvt|300|PS|hp kW|0}} at 2,810 rpm (max. continuous) at sea level
|specpower={{cvt|30.01|PS/L|hp/cuin kW/L|2}}
|compression=6.2:1
|fuelcon=
|specfuelcon={{cvt|0.220|kg/PSh|lb/hph kg/kWh|3}} at max continuous
|oilcon={{cvt|0.003|kg/PSh|lb/hph kg/kWh|3}} at max continuous
|power/weight={{cvt|1.333|PS/kg|hp/lb kW/kg}}
- B.M.E.P.: {{cvt|9.71|atm|bar psi}}
- Reduction gear: Stoekicht sun and planet gears 0.666:1
}}
References
{{Reflist}}
=Works cited=
- {{cite book |title= World Encyclopaedia of Aero Engines |last=Gunston |first=Bill |edition=2 |year=1989 |publisher=Patrick Stephens Ltd |location=Wellingborough |isbn=1-85260-163-9}}
{{Hirth aeroengines}}
Category:Hirth aircraft engines