UL390i | ULPower Aero Engines

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	3888 cc (237.2 cu in)
Bore	105.6 mm [4.157 in]
Stroke	74 mm [2.913 in]
Compression Ratio	8.16 : 1
Firing Order	1 - 4 - 5 - 2 -3 - 6
Direction of Rotation	Clockwise - seen from cockpit
Maximum Torque (ISA conditions)	320 Nm [236 ft.lb] @ 2800 rpm
Power rating (ISA conditions)	140 hp @ 3300 rpm / 130 hp @ 2800 rpm
Installed weight	100 kg [220 lbs] (including all accessories, oil and exhaust)
DC output	50 A
Oil capacity	Min 3,5 L [0.92 US gal]
Fuel	Regular unleaded automotive gasoline with min. 95 RON/ 87 MON ( 91 AKI) AVGAS 100LL or AVGAS UL91 may also be used if regular fuel is not available.

Performance

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 UL390i 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 UL390i engine at different RPM settings, WOT (wide open throttle) and varying density altitude.

Power vs MAP

Dimensions & weights

Dimensions

Dimension	Weight
Maximum dimension in X direction (length)*	723 mm [28.4 inch]
Maximum dimension in Y direction (width)*	654 mm [28.97 inch]
Maximum dimension in Z direction (height)*	472 mm [18.6 inch]

Weights

Dry weight of the basic standard engine from serial production: 85,3 kg (188 lb)
Ready-to–fly weight: 100 kg (220.4 lb)

For more details please check the technical data document.

Fuel consumption

Fuel consumption (Liter/hour)

Specific fuel consumption

These are values at full throttle. When cruising estimated average is UL390 ±21l.
(depending on type of plane, personal style of flying, cruise speed , climate circumstances)

Price & options

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