190 CN4 – air-cooled four-cylinder boxer engine
Design and Features
It is the most powerful engine in MVVS's offer. Its cylinder unit is based on a proven 50 cc air-cooled engine.The exhausts are oriented to the underside, under the engine. Crankcase made by precise CNC machining from solid material. The crankshaft is mounted in four ball bearings. The connecting rod has both eyes fitted with needle bearings. The pistons are made of aluminum alloy with a high silicon content. The piston has a special surface treatment that reduces friction and ensures longer life. Aluminum alloy cylinders have an internal working surface treated with the nikasil method.
The engine is typical for smooth running, easy starts and a flat course of torque.
The preparation of the mixture is controlled by two Walbro carburettors with a choke and a diaphragm pump. The ignition is battery powered with electronics and a microprocessor controlled ignition timing and with safety functions.
Technical Specification
| Model | 190 CN4, boxer, 2-stroke, 4-cylinder | |
| Displacement | 191 cm3 | |
| Air/water-cooled | ✔ / X | |
| Bore/Stroke | 40/38 mm | |
| Max. output (without generator) | 20,5 PS (15,3kW) @ 6500 min-1 | |
| Practical RPM range | 3000 - 5900 min-1 | |
| RPM range | 1000 - 9000 min-1 | |
| Weight (without generator) | 4421 g | |
| Spark plug | NGK M10 (CM-6) | |
| Fuel | Unleaded 95-octane fuel | |
| Lubrication | Oil (Mobil Racing 2T) with petrol in mixture 1:40 | |
| Recommended propeller | Mejzlik 32x12 (2B), 31x12 (2B), 30x13 (3B) | |
| Recommended headers | 2x 3426LR | |
| Recommended exhausts | 2x 3511 or 2x 3611 | |
| Fuel supply | 2x Carburettor (HDA189) | EFI system |
| Weight of fuel supply | 2x 128 g | 400 g |
| Ignition | 2x ICU-B | 2x ICU-BI |
| Weight of ignition | 2x 264 g | 2x 168 g |
| Fuel consumption 4000 RPM | 5,37 l/hour | 3,94 l/hour |
| Fuel consumption 5100 RPM | 7,5 l/hour | 4,73 l/hour |
| Fuel consumption 5700 RPM | 7,35 l/hour | 7,1 l/hour |
| Operating enviromental limits | 3000 m | 5000 m |
| Endurance time | Approx. 300 hours (every 100 hours check) | Approx. 360 hours (Check every 80 hours check) |
| Start-ability | X | ✔ |
| System programming | X | ✔ |
| Engine control | X | ✔ |
| Installation ease | ✔ | X |
| Electric starter with controller | ✔ | ✔ |
| Ignition | 2x ICU-BS | 2x ICU-BSI |
| Weight of starter (and controller) | 686 g | 686 g |
| Static thrust | Propeller 30x13 | Propeller 32x12 |
| RPM | 7000 min-1 | 5900 min-1 |
| Thrust | 45 kg | 36 kg |
