OS MAX RE 49 PI-II

Swept chamber volume 4.97 cc. Air-cooled four-stroke motor. A further development of the existing Wankel motor, Order No. 1801, with numerous improvements:

- New carburettor with mixture control and air intake trumpet
- Unlike the previous version, can be operated with fuel containing synthetic oil
- Designed for a normal type "F" glowplug
- New, more effective silencer

The OS MAX RE 49 PI-II motor is a rotary-piston engine based on the principle developed by Dr. Felix Wankel. Instead of the reciprocating piston and cylinder of a conventional engine, the rotary-piston engine features a three-lobed rotor which rotates in a circular path inside a housing in the form of a twin-lobed trochoid, whilst also rotating itself. This planetary movement is determined by an eccentric shaft, a hollow gear in the rotor and a fixedpinion in the engine's crankcase; the result is that the intake / combustion chamber enlarges and diminishes cyclically. The fuel / air mixture drawn into the engine is compressed and forced into the combustion chamber where it is ignited and expands, generating a force acting upon the eccentric shaft. Spring-loaded sealing strips at the edges of the rotor prevent the gases flowing from one compartment into another. Intake and outlet are controlled by transferports, as in a conventional two-stroke piston engine.

Pronounced fins on the combustion side of the trochoid provide effective cooling, and the motor has no tendency to overheat. The characteristic feature of the rotary engine is the virtually complete absence of vibration, in marked contrast to conventional piston engines of comparable power, which cannot compete in this respect. The engine works on the four-stroke principle, and for thisreason is very easy to silence effectively. The carburettor provides proportional control of engine speed. The engine is supplied with a mounting ring which provides a simple, reliable method of attachment to the nose bulkhead of the model's fuselage using a three-point mounting.