Hirth F-23
| Hirth F-23 | |
|---|---|
| Type | Twin cylinder two-stroke aircraft engine |
| National origin | Germany |
| Manufacturer | Hirth |
| Unit cost | US$4423 (base price 2009) |
The Hirth F-23 is a twin cylinder, horizontally-opposed, two stroke, carburetted or optionally fuel injected aircraft engine designed for use on ultralight aircraft.[1][2][3]
Development
The F-23 is intended to compete with the 50 hp (37 kW) Rotax 503 and is differentiated from the Rotax powerplant by offering a horizontally-opposed cylinder layout. The F-23 uses free air cooling and piston-ported induction, with dual Bing 34mm slide or optional diaphragm type carburetors. The cylinder walls are electrochemically coated with Nikasil. Standard starting is recoil start. A belt reduction drive system, fuel injection, tuned exhaust and electric start are optional.[1][2]
The engine runs on a 50:1 pre-mix of unleaded 93 octane auto fuel and oil. Recommended time between overhauls is 1000 hours.[1][2]
The F-23 produces 50 hp (37 kW) at 6150 rpm and 40 hp (30 kW) at 5500 rpm.[1][2]
Applications
Specifications (F-23)
Data from Recreational Power Engineering[2]
General characteristics
- Type: Twin cylinder, two-stroke, aircraft engine
- Bore: 72 mm (2.8 in)
- Stroke: 64 mm (2.5 in)
- Displacement: 521 cc (31.8 cu in)
- Length: 247 mm (9.7 in)
- Width: 570 mm (22.4 in)
- Height: 338 mm (13.3 in)
- Dry weight: 84 lb (38.1 kg) including reduction unit, full exhaust system and electric start
Components
- Valvetrain: piston-ported
- Fuel system: 2 X Bing 34mm slide or optional diaphragm type carburetor or fuel injection
- Fuel type: unleaded 93 octane auto fuel
- Oil system: 50:1 fuel/oil premix
- Cooling system: free air
- Reduction gear: cog belt with 1.8:1, 2.2:1 and 2.5:1 ratios optional
Performance
- Power output: 50 hp (37 kW) at 6150 rpm
- Compression ratio: 9.5:1
References
- 1 2 3 4 Cliche, Andre: Ultralight Aircraft Shopper's Guide 8th Edition, page G-3 Cybair Limited Publishing, 2001. ISBN 0-9680628-1-4
- 1 2 3 4 5 Recreational Power Engineering (n.d.). "F-23 2 cycle 50hp". Retrieved 17 January 2013.
- ↑ Purdy, Don: AeroCrafter - Homebuilt Aircraft Sourcebook, page 72. BAI Communications. ISBN 0-9636409-4-1