Question

Write note on knocking and antiknocking.

Answer 1

Knocking (also knock, detonation, spark knock, pinging or pinking) in spark-ignition internal combustion engines occurs when combustion of some of the air/fuel mixture in the cylinder does not result from propagation of the flame front ignited by the spark plug, but one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front.
(Automotive Engineering) a compound, such as lead tetraethyl, added to petrol to reduce knocking in the engine