Answer:
Both are correct
Step-by-step explanation:
Not all are flowers in the path of engine progress and development. There is a phenomenon that haunts technicians since the beginning of engine development and, it seems, will always be present in the lives of those who work with the engines, this phenomenon is called abnormal combustion, also known as spark knock, ping, and detonation.
During abnormal combustion the increase in temperature and pressure within the combustion chamber which can cause serious engine damage.