Vapour lock is a term used to describe when fuel vaporises in the fuel system of an engine, resulting in a disruption of fuel flow. The spelling of this word can be explained using the International Phonetic Alphabet (IPA) as /ˈveɪpər lɒk/. The "v" sound is pronounced as a voiced bilabial fricative, while the "ou" in "vapour" is pronounced as the diphthong /aʊ/ in British English. The "o" in "lock" is pronounced using the short vowel /ɒ/, resulting in the word "vapour lock".
Vapour lock is a technical term that is commonly used in the realm of automotive engineering and refers to a condition where the flow of liquid fuel is interrupted or hindered due to the formation of vapour bubbles in the fuel line. It occurs within the fuel delivery system, typically in the fuel lines, pump, or carburetor, and results in difficulties or completely halting the engine's operation.
The phenomenon of vapour lock occurs when the fuel vaporizes prematurely instead of reaching the combustion chamber. This usually transpires when the temperature of the fuel rises significantly, causing the liquid fuel to transform into vapour before entering the engine. The vapour bubbles then create an obstruction in the fuel delivery system, impeding the continuous flow of fuel to the engine, which results in a loss of power and often leads to engine stalling or failure to start.
Vapour lock can be caused by various factors, including extremely high ambient temperatures, inadequate cooling of the fuel lines, low fuel levels, or a malfunctioning fuel pump. It is more commonly associated with older vehicles that have carbureted fuel systems as compared to modern cars with fuel injection systems.
To mitigate vapour lock, various measures can be taken, such as insulation of fuel lines, installation of heat shields, ensuring proper cooling of the fuel pump, and maintaining adequate fuel levels. Additionally, modern fuel injection systems are designed to reduce the occurrence of vapour lock by pressurizing the fuel and utilizing cooling mechanisms.
The term "vapour lock" originated in the early 20th century and is derived from two distinct words: "vapour" and "lock".
1. Vapour: The word "vapour" refers to the gaseous form of a substance, typically at a temperature below its boiling point. In the context of vapour lock, it refers to the formation of vapor or gas within a closed system, causing disruption or blockage.
2. Lock: The word "lock" in this context means a stopping or obstruction. It can be traced back to the Old English word "loc", which implies something that is closed, tight, or secure.
Therefore, "vapour lock" can be understood as the obstruction or blockage caused by the formation of gas or vapor within a system.