What is pre-ignition caused by hot combustion chamber surfaces prior to spark discharge called________________?
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Answer: B. preignition
Explanation
Preignition occurs when hot spots inside the combustion chamber ignite the fuel prematurely. This ignition happens before the spark plug fires during the compression stroke. It creates opposing pressure forces that can severely damage internal engine components. Hot spots can be caused by carbon deposits, overheated spark plugs, or sharp edges. Premature combustion increases peak cylinder pressures and causes engine knocking. Control of combustion chamber temperatures prevents this unwanted early fuel ignition.
High-performance engines require proper cooling and clean chambers to prevent preignition. Uncontrolled preignition can lead to melted pistons and cracked cylinder heads quickly. Engine management systems monitor knock sensors to adjust timing and prevent damage. Auto-ignition generally refers to spontaneous ignition of end gas without a flame front. Retarded ignition delays the spark timing relative to top dead center positions. Detonation is an explosive auto-ignition of the end gas following normal spark ignition.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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