• 108kg
  • 180hp
  • contact us

This 5.2 liter, 6 cylinder engine delivers up to 180 hp and runs on minimum 95 oct mogas!

With only 108 kg (238 lb) you will love this engine.

We are pleased to inform you that the NEW UL520i (from 223501 ) engines have an updated ECU map which will allow the engine to run on MoGas 91 RON fuel . This possibility will open up many doors in regions where customers are struggling to obtain higher octane fuel .
IMPORTANT REMARK: for 520i engines with a serial number lower than 223501, you still need to use minimum 95 RON fuel (labelled as 91 AKI fuel in USA / Canada). (Contact your dealer if you would like to update the ECU map in order to be able to run your 350i / 520i engine on 91 RON)

  • 4 stroke, 6 cylinder, horizontally opposed
  • Dual (redundant) electronic spark ignition (variable timing)
  • Electronic multipoint fuel injection (pressure and temperature compensated)
  • Electronic RPM limiter
  • Direct propeller drive
  • 7 bearing crankshaft with surface hardening treatment and additional large thrust bearing (ball bearing type)
  • Single central camshaft
  • Push rods, tappets and OHV (hydraulic compensators have not been used)
  • Wet sump forced lubrication with integrated pressure regulator
  • Ram air cooled cylinders and cylinder heads
  • Integrated permanent magnet AC generator, external rectifier-regulator
  • Electric starter
  • Electric fuel pump and pressure regulator to eliminate vapor lock and facilitate starting even under adverse conditions
Displacement 5254 cc
Bore 105.6 mm
Stroke 100 mm [3.937 in]
Compression Ratio 8 : 1
Firing Order 1 - 4 - 5 - 2 - 3 - 6
Direction of Rotation Clockwise - Pilot's view
Maximum Torque
(ISA conditions)
425 Nm [313 ft.lb] @ 2600 rpm
Power rating
(ISA conditions)
180 hp @ 3300 rpm / 170 hp @ 2800 rpm
Installed weight 108 kg (including starter motor and alternator)
DC output 50 A
Oil capacity Min 3,5 L
Fuel MOGAS with min. 95 RON / 87 MON (= 91 AKI ) octane rating or AVGAS
NEW 520i engines with a serial number above 223501, can run on 91 RON / 83 MON fuel (labelled as 87 AKI fuel in USA / Canada)

Power / Torque curve

The power and torque curve of the engine has been established by repeated dyno tests, which were performed at sea level and in weather conditions close to the ISA standard. The following graph shows the real, available power and torque coming from the crankshaft of the UL520i engine corrected to the International Standard Atmosphere conditions at sea level.

Power vs Density Altitude

The following graph shows the calculated available power of the UL520i engine at different RPM settings, WOT (wide open throttle) and varying density altitude.

Power vs MAP


Dimension Weight
Maximum dimension in X direction (length)* 723 mm [28.4 inch]
Maximum dimension in Y direction (width)* 736 mm [28.97 inch]
Maximum dimension in Z direction (height)* 472 mm [18.6 inch]


  • Dry weight of the basic standard engine from serial production: 93,3 kg (205 lb)
  • Ready-to–fly weight: 108 kg (238 lb)

For more details please check the technical data document.

Fuel consumption (Liter/hour)

Specific fuel consumption

These are values at full throttle. When cruising estimated average is UL520 ±25l.
(depending on type of plane, personal style of flying, cruise speed , climate circumstances)

The following is a list of the ULPower engine standard design features, all included at no additional cost.

  • Dual (redundant) electronic spark ignition (variable timing)
  • Multi-point electronic fuel injection with automatic altitude and temperature compensation
  • Electronic RPM limiter
  • Rubber mounts
  • Alu ram airboxes
  • Breather with Oil/Air separator (including: temperature resistant hoses and banjo connections)
  • Direct propeller drive
  • ECU (electronic control unit) and mil spec wiring loom
  • Wet sump forced lubrication with integrated pressure regulator
  • Stainless steel exhaust and muffler included
  • One electric fuel pump, two fuel filters, fuel pressure regulator (not included with the UL520T)
  • Oil and air filter
  • Oil and air temperature sensors, Oil and fuel pressure sensors, Air pressue sensor which provide data read-out through RS232 OR CANBUS

Extra options

  • EGT Sensor kit
  • CHT Sensor kit
  • Fuel connection kit
  • Oil Cooler kit
  • Double ecu
  • Different types of prop flanges
  • Different exhaust systems
  • Swiveling oil pick-up tube
  • Dual alternator
  • Forced air cooling
  • Intercooler kit

Please contact us for more info / prices

Collection of ULPower spare parts
More questions? We've got you covered!

Visit our engine FAQ or contact us.

Note: Pictures may not always represent the exact colour or shape.
All prices indicated are excluding taxes and transportation costs.
Deliveries to private individuals within the European Union are subject to 21% Belgian VAT. Prices subject to change without notice.