D-Motor LF26
The D-Motor LF26 is a lightweight liquid cooled side-valve four-stroke flat four, 2.7 litre petrol aircraft engine, produced by D-Motor in Deerlijk, Belgium.[1]
| D-Motor LF26 | |
|---|---|
| Type | Piston aero engine | 
| National origin | Belgium | 
| Manufacturer | D-Motor | 
| Developed into | D-Motor LF39 | 
Design and development
    
This direct-drive aero-engine is unusual in two respects: it is very oversquare with a bore:stroke ratio of 1.295:1, and it has a side-valve (flathead) valvetrain. The designer determined that since maximum continuous power output (65.3 kW[2]) was to be developed at only 2800 rpm, the extra weight and complexity of overhead valves (OHV) would be superfluous. The resulting engine is compact and lightweight, with a dry weight of 58 kg (128 lb),[2] and a maximum power-to-weight ratio of 1.09 kW/kg (wet; coolant fluids weigh 5 kg (11 lb)[2]). The engine has port injection, a dry sump lubrication system, and dual ignition.
Variants
    
With the aid of funding from the Belgian government,[3] D-Motor has developed a derivative 4-litre flat-six engine, the D-Motor LF39, which is claimed to produce 125 PS (92 kW) and to have dry weight of 78 kg (172 lb).[4]
Applications
    
    
Specifications
    
Reference: D-Motor[2]
General characteristics
    
- Type: 4-cylinder liquid-cooled horizontally-opposed piston engine
 - Bore: 103.6mm (4.079 in)
 - Stroke: 80 mm (3.15 in)
 - Displacement: 2690 cm3
 - Length: 611 mm
 - Width: 533 mm
 - Height: 382 mm
 - Dry weight: 58 kg with exhaust, radiator & external oil tank
 
Components
    
- Valvetrain: camshaft in block, side valves
 - Fuel system: port injection
 - Fuel type: AVGAS 100/130 or petrol 91, 93, 95, 98 RON
 - Oil system: Dry sump
 - Cooling system: liquid cooling
 
Performance
    
- Power output: Max 68.9 kW (93.7 PS; 92.4 hp) at 3,100 RPM; continuous 65.3 kW (88.8 PS; 87.6 hp) at 2,800 RPM
 - Compression ratio: 8:1
 - Fuel consumption: 16 litres/h at 100 % power
 - Power-to-weight ratio: Max 1.09 kW/kg (wet); continuous 1.04kW/kg (wet)
 
See also
    
Comparable engines
- HKS 700E
 - Jabiru 2200
 - KFM 112M
 - Revmaster R-2300
 - Rotax 912
 - Sauer S 2200 UL
 - Sauer S 2400 UL
 - Sauer S 2100 ULT
 - ULPower UL260i
 - Verner 133M
 
Related lists
References
    
- "Belgium firm offers Light Sport engine". AOPA Pilot: 40. March 2015.
 - "LF26 specifications". D-motor. Archived from the original on 16 July 2019. Retrieved 16 July 2019.
 - "Kapelstraat 198 8540 Deerlijk - News". D-motor1.vpweb.be. Archived from the original on 28 March 2012. Retrieved 10 May 2012.
 - "D-motor dmotor LF39 specifications". www.d-motor.eu. Archived from the original on 1 September 2016. Retrieved 11 August 2016.
 - D-Motor (n.d.). "X-air test plane". Archived from the original on 17 December 2010. Retrieved 2 August 2011.