• 90.4kg
  • 150hp
  • contact us

This powerful engine is developed for helicopters and gyrocopters and is equipped with a forced cooling system. While hoovering the natural airflow is not sufficient to cool down the cylinder heads. So a fan driven by the crankshaft, blows air along the aluminium air boxes.

Thanks to the modified camshaft and inlet collector the UL350IHPS generates up to 150HP at 3500 rpm. This forced cooling system has an integrated oil radiator.

The forced cooling system can be installed on all ULPower engines which mean they can all be used in helicopter applications.

  • 4 stroke, 4 cylinder, horizontally opposed
  • Dual (redundant) electronic spark ignition (variable timing)
  • Electronic multipoint fuel injection (pressure and temperature compensated)
  • Electronic RPM limiter
  • Direct propeller drive
  • 5 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 3503 cc [213.77 cu in]
Bore 105.6 mm [4.157 in]
Stroke 100 mm [3.937 in]
Compression Ratio 8.7 : 1
Firing Order 1 - 3 - 2 - 4
Direction of Rotation Clockwise - Pilot's view
(ISA conditions)
315 Nm (232 ft.lbs) @ 2800 rpm
Power rating
(ISA conditions)
150 hp @ 3500 rpm /  131 hp @ 3000 rpm
Installed weight 78.4 kg [172.8 lbs] (including starter motor and alternator) + 12kg (forced cooling inclusive oil cooler and lines)
DC output 30 Amp
Oil capacity Min 2,5L
Fuel MOGAS with min. 97 RON/88 MON (= 93 AKI) octane rating or AVGAS

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 UL350iHPS engine corrected to the International Standard Atmosphere conditions at sea level.


Dimension Weight
Maximum dimension in X direction (length)* 685.0 mm [26.9 inch]
Maximum dimension in Y direction (width)* 736 mm [28.97 inch]
Maximum dimension in Z direction (height)* 550 mm [21.6 inch]


  • Dry weight of the basic standard engine from serial production: 66,1 kg (145,73 lb)
  • Ready-to–fly weight: 90,4 kg (199.3 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 UL350 ±18l.
(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.