3.2.2.3. Ventilation of the engine
Ventilation of the engine is necessary that in the case of a bent shaft there was no harmful excessive pressure.As piston rings cannot carry out rather densely sealing, combustible gases get into a case of a bent shaft. Mix of hot oil and vapors of fuel can create the excessive pressure which harmfully influences the krivoshipno-conrod mechanism. In order to avoid it gases have to be sucked away through a connecting hose of the engine and be burned.
The closed ventilation of the engine does not demand maintenance.