Q7. A. State, with reasons, THREE properties required of crankcase oil which is to be used for a trunk piston main engine.
B. Explain how a representative sample of crankcase oil would be obtained from a trunk piston engine. C. Briefly describe the action to be taken if the crankcase oil charge cannot immediately be replaced and analysis shows – (i) Water is present; (ii) Alkalinity has fallen; (iii) Viscosity has changed appreciably; (iv) Carbon content has increased.