Question 210Motor Plants - 1st Asst/Chief

The correct answer is C) The ratio of oil mist to air in the crankcase. The size of a crankcase explosion due to a hot spot is primarily dependent on the ratio of oil mist to air in the crankcase. When the oil mist reaches a certain concentration and is ignited by the hot spot, it can cause a violent explosion. The temperature of the hot spot, the amount of debris in the oil, or the water content in the oil are not the primary factors that determine the explosion size. Instead, the concentration of the oil mist is the critical element that governs the potential for a large crankcase explosion.