| Diesel engine principles are pretty straight | | | | intake air in the cylinder which allows |
| forward for the experienced mechanic but what | | | | compression to take place, the HEAT OF |
| about regular everyday people who have never | | | | COMPRESSION is reached when the piston |
| taken the time to find out more about a | | | | reaches the top of the cylinder, the diesel |
| diesel engine and how it works? | | | | fuel is then injected into the cylinder at |
| | | | the precise time. |
| I am going to explain in layman's terms the | | | | |
| basic principles of a diesel engine. | | | | 3} POWER STROKE: |
| | | | |
| WHAT'S THE DIFFERENCE BETWEEN A GASOLINE | | | | After injection takes place an explosion |
| ENGINE AND A DIESEL ENGINE?...a quick | | | | occurs in the cylinder because of the |
| overview. | | | | combination of heat and atomized diesel fuel. |
| | | | This causes the piston to be forced downward |
| The first thing you should know is a gasoline | | | | which produces torque and the horsepower |
| engine and a diesel engine are totally | | | | required from a typical diesel engine. |
| different. A gasoline engine is constructed | | | | |
| much lighter than the heavier built diesel | | | | 4} EXHAUST STROKE: |
| engine and runs on an air/fuel mixture | | | | |
| combined with a high energy spark that is | | | | After the power stroke the piston moves |
| timed to ignite the air/fuel mixture inside | | | | upward once again while the exhaust valves |
| each engine cylinder at the precise time | | | | open allowing the previously ignited gases to |
| creating power and torque [turning force] | | | | escape to the atmosphere out the exhaust |
| which drives your vehicle. | | | | system. |
| | | | |
| A diesel engine uses high compression [intake | | | | As mentioned before each cylinder goes |
| air that is compressed / squished] into a | | | | through this exact sequence over and over in |
| very small space inside each cylinder causing | | | | a set firing order. For instance, a 6 |
| extreme heat! This is called 'Heat Of | | | | cylinder diesel engine has a firing order 1- |
| Compression' which ignites a very fine high | | | | 5- 3- 6- 2- 4 This is the order that each |
| pressure mist of diesel fuel that is injected | | | | cylinder goes by, following the 4 strokes |
| into the cylinder at the exact time. | | | | mentioned above. This sequence has been |
| | | | engineered to allow the diesel engine to run |
| So you now know that a gasoline engine needs | | | | smoothly with no imbalance. |
| a high energy spark to run while a diesel | | | | |
| uses 'Heat Of Compression' | | | | DIESEL ENGINE TRIVIA: Today's high |
| | | | performance diesel engines. |
| THE FOUR STROKE PRINCIPLE | | | | |
| | | | Fuel passes through the injector at speeds of |
| Every engine today runs on FOUR STROKES or | | | | nearly 1500 miles per hour - as fast as a jet |
| FOUR CYCLES- both these terms mean the same. | | | | plane at top speed. |
| Here is how the four stroke diesel engine | | | | |
| operates. | | | | Fuel is injected into the combustion chamber |
| | | | in less than 1.5 milliseconds, the same time |
| The four strokes are: | | | | it takes for a camera flash to go off. |
| INTAKE-COMPRESSION-POWER-EXHAUST. The | | | | |
| pistons, valves and injectors work together | | | | The minimum amount of fuel injected into a |
| in each cylinder in a set sequence over and | | | | diesel engine is one cubic millimetre - about |
| over. | | | | the same volume as the head of a pin. |
| | | | |
| 1} INTAKE STROKE: | | | | Volkswagen has developed a 1 litre diesel |
| | | | powered car that got 100 kilometres out of |
| Intake valves in the cylinder head open | | | | .89 litres of fuel {60 miles on |
| allowing pressurized air to enter each | | | | approxiamately 3/4 of a quart of fuel!} |
| cylinder while the piston is travelling | | | | |
| downward.{the pressurized air supply is made | | | | There is much to learn about diesel engines |
| possible by the TURBOCHARGER which pushes air | | | | and a ton of information online. If you have |
| into the intake system giving the diesel | | | | ever considered buying a vehicle with a |
| engine a boost of air to keep up with | | | | diesel engine you have my blessing! The extra |
| instantaneous injection of fuel} | | | | cost will be to your benefit, so I recommend |
| | | | finding out more about diesel engines before |
| 2} COMPRESSION STROKE: | | | | you decide which one to choose.. |
| | | | |
| When the piston starts to make it's way back | | | | I hope you have found this information on |
| upward the valves close which traps the | | | | diesel engines helpful! |