Q6. With reference to two stroke, slow speed engines:
Explain what is meant by the term thermal stress and how this can cause cracking of the crown surfaces; (4)
Sketch a cross section of a piston, labelling the MAIN components and indicating coolant flow; (8)
State a cause of EACH of the following defects:
(i) Burning of the crown upper surfaces; (2) (ii) Carbon deposits in the cooling spaces. (2)