Parts

Question 1

Define the term “Diesel engine”

Answer 1

A diesel engine is a mechanical machine that produces power by burning oil (diesel fuel) mixed with air and compressed in a cylinder by a piston.

Question 2

Listed the principle component parts of a diesel engine?

Answer 2

Cylinder, piston, connecting rod, crankshaft, camshaft, timing gears, valves/ports

Question 3

Describe the principle component parts of a diesel engine?

Answer 3

1. ) cylinder – the cylinders is the housing in which fuel–air mixture is burned.
2. ) piston– the piston is the cylindrical part, closed at one end, which slides in the cylinder.
3. ) connecting rod – the connecting rod is the part that connects the piston to the crankshaft and thereby transmits piston thrust to the crankshaft.
4. ) Crankshaft – the crankshaft is the main shaft of the engine. It is turned by the connecting rods. The crankshaft converts piston linear motion to rotary motion suitable for driving an electric generator or other machinery.
5. ) Valves/ports– the valves/Ports are openings through which air enters and exhaust gases exit the cylinders.
6. ) Camshaft – the camshaft is an auxiliary shaft of the engine. It rotates to open and close the intake and exhaust valves. The camshaft is normally rotated a chain and gear combination which is connected to the crankshaft. It may also be driven directly from the crankshaft by a combination of gears.
7. ) Timing gears – The timing gears rotate the camshaft so that the intake and exhaust valves are open at the correct time relative to the position of the piston in the cylinder.

Question 4

What is a diesel cylinder?

Answer 4

A diesel cylinder is the housing in which fuel –air mixture is burned.

Question 5

What is a diesel piston?

Answer 5

The piston is the cylindrical part, closed at one end, which slides in the cylinder. The piston converts the expansion force of combustion to linear (straight – line) mechanical motion.

Question 6

Define the term connecting rod for a diesel engine?

Answer 6

The connecting rod is the part that connects the piston to the crankshaft and thereby transmits piston thrust to the crankshaft.

Question 7

Define the term crankshaft as it pertains to a diesel engine?

Answer 7

The crankshaft is the main shaft of the engine. It is turned by the connecting rods. The crankshaft converts piston linear motion to rotary motion suitable for driving an electric generator or other machinery.

Question 8

Define the term valves/ports as it pertains to a diesel engine

Answer 8

The valves/ports are openings through which air enters and exhaust gases exit the cylinders.

Question 9

Define the term cam shaft as it pertains to a diesel engine?

Answer 9

The camshaft is an auxiliary shaft of the engine. It rotates to open and close the intake and exhaust valves. The camshaft is normally rotated by a chain and gear combination which is connected to the crankshaft. It may also be driven directly from the crankshaft by a combination of gears.

Question 10

Define timing gears as it pertains to a diesel engine?

Answer 10

The timing gears rotate the camshaft so that the intake and exhaust valves are open at the correct time relative to the position of the piston in the cylinder.

Question 11

The internal combustion process of a diesel engine involves a sequence of four events, what are they?

Answer 11

Intake, compression, power, exhaust.

Question 12

Define intake?

Answer 12

Air is admitted into the cylinder

Question 13

Define compression?

Answer 13

Air is compressed by the piston into a smaller volume. The pressure is increased and the temperature is increased.

Question 14

In the Combustion and power process. What is power?

Answer 14

Power is where the fuel is injected into the cylinder with the compressed air. The air fuel mixture is burned and expands. The expansion of the burned mixture forces the piston away from the cylinder head.

Question 15

In the combustion power process of a diesel engine what is exhaust?

Answer 15

Exhaust - is the gas resulting from burning of the air fuel mixture and expelled from the cylinder.

Question 16

Two-stroke cycle means what per revolution?

Answer 16

Two-stroke cycle means one power stroke out of each revolution.

Question 17

Four stroke cycle means what pertaining to revolution?

Answer 17

Four stroke cycle means one power stroke out of two revolutions

Question 18

What are the diesel engine operating characteristics?

Answer 18

1. Burns diesel fuel, which is a light oil.
2. Fuel and air mix in the cylinder. Air enters and is compressed. Fuel is injected into the high temperature air.
3. High compression ratio (14:1 to 25:1; maximum cylinder volume: minimum cylinder volume).
4. Heat of compressed air ignites the fuel.

Question 19

What is a diesel engines compression ratio?

Answer 19

14:1 to 25:1

Question 20

What are the diesel engine auxiliary support systems?

Answer 20

1. Intake air – Provides combustion air
2. Fuel oil – Provides fuel for combustion
3. Exhaust – Removes combustion gases and reclaims lost power
4. Lubrication – Provides lubrication to the engine parts
5. Cooling – Provides coolant to keep the engine cool
6. Starting air– provides compression air to start the engine

Question 21

Describe how fuel and air are combined and burned in a diesel engine?

Answer 21

Fuel is injected into compressed air in the cylinder and ignited by the heat of the compressed air.

Question 22

Describe why, in a two stroke and four stroke engine of the same size, a two-stroke engine is capable of producing more power?

Answer 22

Because for the same number of engine revolutions the two-stroke engine has more power strokes.