Internal Combustion Engines Flashcards
A diesel engine requires five supporting systems in order to operate
Air intake, exhaust, cooling, lubrication, and fuel injection
The back and forth motion of one or more pistons is transformed into the rotary motion of the crankshaft
Reciprocating engines
Diesel engines are not self speed limiting because the air entering the engine is
Always the maximum amount
Engine speed is limited solely by
The amount of fuel injected into the engine cylinders
Diesel engines require a _____ to control the amount of fuel being injected into the engine
Speed limiter (governor)
A diesel engine does not require ____
An ignition system
In a diesel engine, the fuel is injected into the cylinder as ____
The piston comes to the top of its compression stroke
When fuel is injected in a diesel engine, it vaporizes and ignites due to
The heat created by the compression of the air in the cylinder
Terms used to define the displacement of an engine
Bore and stroke
Displacement is measured in
Cubic inches or litres
Diametre of the engine’s cylinders
Bore
The distance the piston travels from the top of the cylinder to the bottom
Stroke
Bore x stroke x number of cylinders equals
Displacement
Highest point of travel by the piston
Top dead center
Lowest point of travel by the piston
Bottom dead center
There are ____ degrees of crankshaft travel between TDC & BDC
180
All events that occur in the engine are related to
The location of the piston
For a diesel engine, power is rated in
Units of horsepower
The power transmitted to the pistons by the gas in the cylinders and is mathematically calculated
Indicated horsepower
Amount of useable power delivered by the engine to the crankshaft
Brake horsepower
Indicated horsepower can be as much as ___ higher than brake horsepower
15%
The difference between indicated and brake horsepower is due to
Internal engine friction, combustion inefficiencies, and parasitic losses
Ratio of an engine’s brake HP and its indicated HP
Mechanical efficiency
Mechanical efficiency of a four cycle diesel
About 82 - 90 percent