What does a spark plug do in a gasoline engine?
AnswerIgnites the fuel-air mixture
The spark plug fires a spark that ignites the compressed mixture.
Vehicles · Facts & stats
Engine facts & stats
7 fact-checked facts about engines and how they work, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
What does horsepower measure?
AnswerPower
Horsepower is a unit of power, the rate of doing work.
Going deeper
What is the order of a four-stroke engine cycle?
AnswerIntake, compression, power, exhaust
Air and fuel come in, get squeezed, ignite, then leave as exhaust.
How is fuel ignited in a diesel engine?
AnswerBy the heat of highly compressed air
Diesels compress air so much it gets hot enough to ignite injected fuel.
A Wankel engine is what kind of engine?
AnswerA rotary engine
It uses a triangular rotor instead of reciprocating pistons.
Expert level
Who built the first practical four-stroke internal combustion engine in 1876?
AnswerNikolaus Otto
The four-stroke cycle is often called the Otto cycle.
One mechanical horsepower equals roughly how many watts?
Answer746
One mechanical horsepower is about 745.7 watts.
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